the cell, chapter 1 complete

8/3/2019 The Cell, Chapter 1 Complete

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BIOLOGY FOR SENIOR HIGH SCHOOL GRADE XI

CHAPTER : 1

STRUCTURE AND FUNCTION OF THE CELL AS THE SMALLEST UNIT OF LIVE

By : Tri Susila Hidayati

Basic competence : describing chemical compounds , structure and function of

cell as the smallest unit of living.

The word cell comes from theLatincellula, meaning, a small room. Most cells are too small to

be seen individually with an unaided human eye and typically range in diameter from about 10 to

30 micrometer ( m ) or 0,01 to 0,03 mm. The cell is the functional basic unit of life. It was

discovered by Robert Hooke in 1665 and is the functional unit of all known living organisms.

Living things are composed of one or more building blocks known as cells that are the basic unit

of structure. Some organisms, such as most bacteria, areunicellular (consist of a single cell).

Other organisms, such ashumans, aremulticellularCells carry out the various processes that

are characteristic of `being alive`.

In 1835, before the final cell theory was developed, Jan Evangelista Purkyn observed small

"granules" while looking at the plant tissue through a microscope. The cell theory, first

developed in 1839 byMatthias Jakob SchleidenandTheodor Schwann, states that all organisms

are composed of one or more cells, that all cells come from preexisting cells, that vital functions

of an organism occur within cells, and that all cells contain thehereditary informationnecessary

for regulating cell functions and for transmitting information to the next generation of cells.
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A.Structure and function of the cell as the smallest unit of live

The cell is the functional basic unit oflife. It was discovered byRobert Hookeand is the

functional unit of all known livingorganisms. It is the smallest unit of life that is classified as a

living thing, and is often called the building block of life. Some organisms, such as mostbacteria,

areunicellular(consist of a single cell). Other organisms, such ashumans, aremulticellular.

Humans have about 100 trillion or 1014

cells; a typical cell size is 10mand a typical cell mass is

1nanogram. The longest human cells are about 135 m in theanterior horn in the spinal cord

whilegranule cellsin thecerebellum, the smallest, can be some 4 m and the longest cell can

reach from the toe to the lowerbrain stem(Pseudounipolar cells). The largest known cells are

unfertilisedostrichegg cells, which weigh 3.3 pounds.

In 1835, before the final cell theory was developed,Jan Evangelista Purkynobserved small

"granules" while looking at the plant tissue through a microscope. Thecell theory, first

developed in 1839 byMatthias Jakob SchleidenandTheodor Schwann, states that all organisms

are composed of one or more cells, that all cells come from preexisting cells, that vital functions

of an organism occur within cells, and that all cells contain thehereditary informationnecessary

for regulating cell functions and for transmitting information to the next generation of cells.

The word cellcomes from theLatincellula, meaning, a small room. The descriptive term for the

smallest living biological structure was coined byRobert Hookein a book he published in 1665

when he compared thecorkcells he saw through his microscope to the small rooms monks

lived in.

Cells in culture,stainedforkeratin(red) andDNA(green)

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There are two types of cells: eukaryotic and prokaryotic. Prokaryotic cells are usually

independent, while eukaryotic cells are often found in multicellular organisms.

Prokaryotic cells

Theprokaryotecell is simpler, and therefore smaller, than a eukaryote cell, lacking anucleus

and most of the otherorganellesof eukaryotes. There are two kinds of prokaryotes:bacteria

andarchaea; these share a similar structure.

Nuclear material of prokaryotic cell consist of a single chromosome that is in direct contact with

cytoplasm. Here, the undefined nuclear region in the cytoplasm is callednucleoid.

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A prokaryotic cell has three architectural regions:

On the outside,flagellaandpiliproject from the cell's surface. These are structures (not

present in all prokaryotes) made of proteins that facilitate movement and

communication between cells;

Enclosing the cell is thecell envelope generally consisting of acell wallcovering a

plasma membranethough some bacteria also have a further covering layer called a

capsule. The envelope gives rigidity to the cell and separates the interior of the cell from

its environment, serving as a protective filter. Though most prokaryotes have a cell wall,

there are exceptions such asMycoplasma(bacteria) andThermoplasma(archaea). The

cell wall consists ofpeptidoglycanin bacteria, and acts as an additional barrier against

exterior forces. It also prevents the cell from expanding and finally bursting (cytolysis)

fromosmotic pressureagainst ahypotonicenvironment. Some eukaryote cells (plant

cellsandfungicells) also have a cell wall;

Inside the cell is thecytoplasmic regionthat contains thecell genome(DNA) and

ribosomes and various sorts of inclusions. Aprokaryotic chromosomeis usually a

circular molecule (an exception is that of the bacteriumBorrelia burgdorferi, which

causes Lyme disease). Though not forming a nucleus, theDNAis condensed in a

nucleoid. Prokaryotes can carryextrachromosomal DNAelements calledplasmids, which

are usually circular. Plasmids enable additional functions, such asantibiotic resistance.

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Eukaryotic cells

Plants, animals, fungi, slime moulds, protozoa, & algae are allEukaryotic. These cells are about

15 times wider than a typical prokaryote and can be as much as 1000 times greater in volume.

The major difference between prokaryotes and eukaryotes is that eukaryotic cells contain

membrane-bound compartments in which specific metabolic activities take place. Most

important among these is acell nucleus, a membrane-delineated compartment that houses the

eukaryotic cell's DNA. This nucleus gives the eukaryote its name, which means "true nucleus."

Other differences include:

The plasma membrane resembles that of prokaryotes in function, with minor

differences in the setup. Cell walls may or may not be present.

The eukaryotic DNA is organized in one or more linear molecules, calledchromosomes,

which are associated withhistoneproteins. All chromosomal DNA is stored in thecell

nucleus, separated from the cytoplasm by a membrane. Some eukaryoticorganelles

such asmitochondriaalso contain some DNA.

Many eukaryotic cells areciliatedwithprimary cilia. Primary cilia play important roles in

chemosensation,mechanosensation, and thermosensation. Cilia may thus be "viewed

as sensory cellularantennaethat coordinate a large number of cellular signaling

pathways, sometimes coupling the signaling to ciliary motility or alternatively to cell

division and differentiation."[7]

Eukaryotes can move using motileciliaorflagella. The flagella are more complex than

those of prokaryotes

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Subcellular components

All cells, whetherprokaryoticoreukaryotic, have amembranethat envelops the cell, separates

its interior from its environment, regulates what moves in and out (selectively permeable), and

maintains theelectric potential of the cell. Inside the membrane, asaltycytoplasmtakes up

most of the cell volume. All cells possessDNA, the hereditary material ofgenes, andRNA,

containing the information necessary tobuildvariousproteinssuch asenzymes, the cell's

primary machinery. There are also other kinds ofbiomoleculesin cells. This article lists theseprimary components of the cell, then briefly describe their function.

Membrane

The cytoplasm of a cell is surrounded by a cell membrane orplasma membrane. The plasma

membrane in plants and prokaryotes is usually covered by acell wall. This membrane serves to

separate and protect a cell from its surrounding environment and is made mostly from adouble

layer of lipids(hydrophobicfat-like molecules) andhydrophilicphosphorusmolecules. Hence,

the layer is called aphospholipid bilayer. It may also be called a fluid mosaic membrane.

Embedded within this membrane is a variety ofproteinmolecules that act as channels and

pumps that move different molecules into and out of the cell. The membrane is said to be

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'semi-permeable', in that it can either let a substance (moleculeorion) pass through freely,

pass through to a limited extent or not pass through at all. Cell surface membranes also contain

receptorproteins that allow cells to detect external signaling molecules such ashormones

Cytoskeleton

The cytoskeleton acts to organize and maintain the cell's shape; anchors organelles in place;

helps duringendocytosis, the uptake of external materials by a cell, andcytokinesis, the

separation of daughter cells aftercell division; and moves parts of the cell in processes of

growth and mobility. The eukaryotic cytoskeleton is composed ofmicrofilaments,intermediate

filamentsandmicrotubules. There is a great number of proteins associated with them, each

controlling a cell's structure by directing, bundling, and aligning filaments. The prokaryotic

cytoskeleton is less well-studied but is involved in the maintenance of cell shape, polarity and

cytokinesis.

Genetic material

Two different kinds of genetic material exist:deoxyribonucleic acid(DNA) andribonucleic acid

(RNA). Most organisms use DNA for their long-term information storage, butsome viruses(e.g.,

retroviruses) have RNA as their genetic material. The biological information contained in an

organism isencodedin its DNA or RNA sequence. RNA is also used for information transport

(e.g.,mRNA) andenzymaticfunctions (e.g.,ribosomalRNA) in organisms that useDNAfor the

genetic code itself.Transfer RNA(tRNA) molecules are used to add amino acids during protein

translation.

Prokaryotic genetic material is organized in a simple circular DNA molecule (the bacterial

chromosome) in thenucleoid regionof the cytoplasm. Eukaryotic genetic material is divided

into different, linear molecules calledchromosomesinside a discrete nucleus, usually with

additional genetic material in some organelles likemitochondriaandchloroplasts(see

endosymbiotic theory).

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http://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Receptor_%28biochemistry%29#Transmembrane_receptorshttp://en.wikipedia.org/wiki/Receptor_%28biochemistry%29#Transmembrane_receptorshttp://en.wikipedia.org/wiki/Hormonehttp://en.wikipedia.org/wiki/Hormonehttp://en.wikipedia.org/wiki/Hormonehttp://en.wikipedia.org/wiki/Endocytosishttp://en.wikipedia.org/wiki/Endocytosishttp://en.wikipedia.org/wiki/Endocytosishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Microfilamenthttp://en.wikipedia.org/wiki/Microfilamenthttp://en.wikipedia.org/wiki/Microfilamenthttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Microtubulehttp://en.wikipedia.org/wiki/Microtubulehttp://en.wikipedia.org/wiki/Microtubulehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNA_virushttp://en.wikipedia.org/wiki/RNA_virushttp://en.wikipedia.org/wiki/RNA_virushttp://en.wikipedia.org/wiki/Retrovirushttp://en.wikipedia.org/wiki/Retrovirushttp://en.wikipedia.org/wiki/Genetic_codehttp://en.wikipedia.org/wiki/Genetic_codehttp://en.wikipedia.org/wiki/Genetic_codehttp://en.wikipedia.org/wiki/MRNAhttp://en.wikipedia.org/wiki/MRNAhttp://en.wikipedia.org/wiki/MRNAhttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Translationhttp://en.wikipedia.org/wiki/Translationhttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Nucleoid_regionhttp://en.wikipedia.org/wiki/Nucleoid_regionhttp://en.wikipedia.org/wiki/Nucleoid_regionhttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Chloroplastshttp://en.wikipedia.org/wiki/Chloroplastshttp://en.wikipedia.org/wiki/Chloroplastshttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Chloroplastshttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Nucleoid_regionhttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Translationhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/MRNAhttp://en.wikipedia.org/wiki/Genetic_codehttp://en.wikipedia.org/wiki/Retrovirushttp://en.wikipedia.org/wiki/RNA_virushttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Microtubulehttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Intermediate_filamenthttp://en.wikipedia.org/wiki/Microfilamenthttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Endocytosishttp://en.wikipedia.org/wiki/Hormonehttp://en.wikipedia.org/wiki/Receptor_%28biochemistry%29#Transmembrane_receptorshttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Molecule


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A human cell has genetic material contained in thecell nucleus(thenuclear genome) and in the

mitochondria (themitochondrial genome). In humans the nuclear genome is divided into 23

pairs of linear DNA molecules calledchromosomes. The mitochondrial genome is a circular DNA

molecule distinct from the nuclear DNA. Although themitochondrial DNAis very small

compared to nuclear chromosomes, it codes for 13 proteins involved in mitochondrial energy

production and specific tRNAs.

Foreign genetic material (most commonly DNA) can also be artificially introduced into the cell

by a process calledtransfection. This can be transient, if the DNA is not inserted into the cell's

genome, or stable, if it is. Certainvirusesalso insert their genetic material into the genome.

Organelles

The human body contains many differentorgans, such as the heart, lung, and kidney, with each

organ performing a different function. Cells also have a set of "little organs," calledorganelles,

that are adapted and/or specialized for carrying out one or more vital functions. Both

eukaryoticand prokaryotic cells have organelles but organelles in eukaryotes are generally

more complex and may be membrane bound.

There are several types of organelles in a cell. Some (such as thenucleusandgolgi apparatus)

are typically solitary, while others (such asmitochondria,peroxisomesandlysosomes) can be

numerous (hundreds to thousands). Thecytosolis the gelatinous fluid that fills the cell and

surrounds the organelles.

9
http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Mitochondrial_genomehttp://en.wikipedia.org/wiki/Mitochondrial_genomehttp://en.wikipedia.org/wiki/Mitochondrial_genomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Mitochondrial_DNAhttp://en.wikipedia.org/wiki/Mitochondrial_DNAhttp://en.wikipedia.org/wiki/Mitochondrial_DNAhttp://en.wikipedia.org/wiki/Transfectionhttp://en.wikipedia.org/wiki/Transfectionhttp://en.wikipedia.org/wiki/Transfectionhttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Organ_%28anatomy%29http://en.wikipedia.org/wiki/Organ_%28anatomy%29http://en.wikipedia.org/wiki/Organ_%28anatomy%29http://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Golgi_apparatushttp://en.wikipedia.org/wiki/Golgi_apparatushttp://en.wikipedia.org/wiki/Golgi_apparatushttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Peroxisomeshttp://en.wikipedia.org/wiki/Peroxisomeshttp://en.wikipedia.org/wiki/Peroxisomeshttp://en.wikipedia.org/wiki/Lysosomeshttp://en.wikipedia.org/wiki/Lysosomeshttp://en.wikipedia.org/wiki/Lysosomeshttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Lysosomeshttp://en.wikipedia.org/wiki/Peroxisomeshttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Golgi_apparatushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Organ_%28anatomy%29http://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Transfectionhttp://en.wikipedia.org/wiki/Mitochondrial_DNAhttp://en.wikipedia.org/wiki/Chromosomehttp://en.wikipedia.org/wiki/Mitochondrial_genomehttp://en.wikipedia.org/wiki/Genomehttp://en.wikipedia.org/wiki/Cell_nucleus


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Cell nucleus eukaryotes only - a cell's information center

Thecell nucleusis the most conspicuous organelle found in aeukaryoticcell. It houses

the cell'schromosomes, and is the place where almost allDNAreplication andRNA

synthesis (transcription) occur. The nucleus is spherical and separated from the

cytoplasm by a double membrane called thenuclear envelope. The nuclear envelope

isolates and protects a cell's DNA from various molecules that could accidentally

damage its structure or interfere with its processing. During processing,DNAis

transcribed, or copied into a specialRNA, calledmessenger RNA(mRNA). This mRNA is

then transported out of the nucleus, where it is translated into a specific protein

molecule. Thenucleolusis a specialized region within the nucleus where ribosome

subunits are assembled. In prokaryotes, DNA processing takes place in thecytoplasm.

Mitochondria and Chloroplasts eukaryotes only - the power generators

Mitochondriaare self-replicating organelles that occur in various numbers, shapes, and

sizes in the cytoplasm of all eukaryotic cells. Mitochondria play a critical role in

generating energy in the eukaryotic cell. Mitochondria generate the cell's energy by

oxidative phosphorylation, usingoxygento release energy stored in cellular nutrients

(typically pertaining toglucose) to generateATP. Mitochondria multiply by splitting in

two. Respiration occurs in the cell mitochondria.

Organelles that are modified chloroplasts are broadly calledplastids, and are involved in

energy storage throughphotosynthesis, which uses solar energy to generate

carbohydrates and oxygen from carbon dioxide and water.

Mitochondria andchloroplastseach contain their own genome, which is separate and

distinct from the nuclear genome of a cell. Both organelles contain this DNA in circular

plasmids, much like prokaryotic cells, strongly supporting the evolutionary theory of

endosymbiosis; since these organelles contain their own genomes and have other

similarities to prokaryotes, they are thought to have developed through a symbiotic

relationship after being engulfed by a primitive cell.
http://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Cell_nucleushttp://en.wikipedia.org/wiki/Eukaryotichttp://en.wikipedia.org/wiki/Eukaryotichttp://en.wikipedia.org/wiki/Eukaryotichttp://en.wikipedia.org/wiki/Chromosomeshttp://en.wikipedia.org/wiki/Chromosomeshttp://en.wikipedia.org/wiki/Chromosomeshttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Nucleolushttp://en.wikipedia.org/wiki/Nucleolushttp://en.wikipedia.org/wiki/Nucleolushttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Mitochondrionhttp://en.wikipedia.org/wiki/Mitochondrionhttp://en.wikipedia.org/wiki/Oxidative_phosphorylationhttp://en.wikipedia.org/wiki/Oxidative_phosphorylationhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Chloroplasthttp://en.wikipedia.org/wiki/Chloroplasthttp://en.wikipedia.org/wiki/Chloroplasthttp://en.wikipedia.org/wiki/Endosymbiosishttp://en.wikipedia.org/wiki/Endosymbiosishttp://en.wikipedia.org/wiki/Endosymbiosishttp://en.wikipedia.org/wiki/Chloroplasthttp://en.wikipedia.org/wiki/Photosynthesishttp://en.wikipedia.org/wiki/Plastidhttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxidative_phosphorylationhttp://en.wikipedia.org/wiki/Mitochondrionhttp://en.wikipedia.org/wiki/Cytoplasmhttp://en.wikipedia.org/wiki/Nucleolushttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Nuclear_envelopehttp://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/DNAhttp://en.wikipedia.org/wiki/Chromosomeshttp://en.wikipedia.org/wiki/Eukaryotichttp://en.wikipedia.org/wiki/Cell_nucleus


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Endoplasmic reticulum eukaryotes only

Theendoplasmic reticulum(ER) is the transport network for molecules targeted for

certain modifications and specific destinations, as compared to molecules that float

freely in the cytoplasm. The ER has two forms: the rough ER, which has ribosomes on its

surface and secretes proteins into the cytoplasm, and the smooth ER, which lacks them.

Smooth ER plays a role in calcium sequestration and release.

Golgi apparatus eukaryotes only

The primary function of the Golgi apparatus is to process and package the

macromoleculessuch asproteinsandlipidsthat are synthesized by the cell. It is

particularly important in the processing of proteins forsecretion. The Golgi apparatus

forms a part of theendomembrane systemof eukaryotic cells.Vesiclesthat enter the

Golgi apparatus are processed in a cis to trans direction, meaning they coalesce on the

cis side of the apparatus and after processing pinch off on the opposite (trans) side to

form a new vesicle in the animal cell.

Ribosomes

Theribosomeis a large complex ofRNAandproteinmolecules. They each consist of two

subunits, and act as an assembly line where RNA from the nucleus is used to synthesise

proteins from amino acids. Ribosomes can be found either floating freely or bound to a

membrane (the rough endoplasmatic reticulum in eukaryotes, or the cell membrane in

prokaryotes).

Lysosomes and Peroxisomes eukaryotes only

Lysosomescontaindigestive enzymes(acidhydrolases). They digest excess or worn-out

organelles, food particles, and engulfedvirusesorbacteria.Peroxisomeshave enzymes

that rid the cell of toxicperoxides. The cell could not house these destructive enzymes if

they were not contained in a membrane-bound system. These organelles are often

called a "suicide bag" because of their ability to detonate and destroy the cell.
http://en.wikipedia.org/wiki/Endoplasmic_reticulumhttp://en.wikipedia.org/wiki/Endoplasmic_reticulumhttp://en.wikipedia.org/wiki/Endoplasmic_reticulumhttp://en.wikipedia.org/wiki/Macromoleculehttp://en.wikipedia.org/wiki/Macromoleculehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Lipidhttp://en.wikipedia.org/wiki/Lipidhttp://en.wikipedia.org/wiki/Lipidhttp://en.wikipedia.org/wiki/Secretionhttp://en.wikipedia.org/wiki/Secretionhttp://en.wikipedia.org/wiki/Secretionhttp://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Vesicle_%28biology%29http://en.wikipedia.org/wiki/Vesicle_%28biology%29http://en.wikipedia.org/wiki/Vesicle_%28biology%29http://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Lysosomehttp://en.wikipedia.org/wiki/Lysosomehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Peroxisomehttp://en.wikipedia.org/wiki/Peroxisomehttp://en.wikipedia.org/wiki/Peroxisomehttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Peroxidehttp://en.wikipedia.org/wiki/Peroxisomehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Virushttp://en.wikipedia.org/wiki/Organellehttp://en.wikipedia.org/wiki/Hydrolasehttp://en.wikipedia.org/wiki/Digestive_enzymehttp://en.wikipedia.org/wiki/Lysosomehttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/RNAhttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Vesicle_%28biology%29http://en.wikipedia.org/wiki/Endomembrane_systemhttp://en.wikipedia.org/wiki/Secretionhttp://en.wikipedia.org/wiki/Lipidhttp://en.wikipedia.org/wiki/Proteinhttp://en.wikipedia.org/wiki/Macromoleculehttp://en.wikipedia.org/wiki/Endoplasmic_reticulum


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Centrosome the cytoskeleton organiser

Thecentrosomeproduces themicrotubulesof a cell a key component of the

cytoskeleton. It directs the transport through theERand theGolgi apparatus.

Centrosomes are composed of twocentrioles, which separate duringcell divisionand

help in the formation of themitotic spindle. A single centrosome is present in theanimal

cells. They are also found in some fungi and algae cells.

Vacuoles

Vacuolesstore food and waste. Some vacuoles store extra water. They are often

described as liquid filled space and are surrounded by a membrane. Some cells, most

notablyAmoeba, have contractile vacuoles, which can pump water out of the cell if

there is too much water. The vacuoles of eukaryotic cells are usually larger in those of

plants than animals.

Structures outside the cell wall

Capsule

A gelatinous capsule is present in some bacteria outside the cell wall. The capsule may be

polysaccharideas inpneumococci,meningococciorpolypeptideasBacillus anthracisor

hyaluronic acidas instreptococci.[citation needed]

Capsules are not marked by ordinary stain and

can be detected byspecial stain. The capsule isantigenic. The capsule hasantiphagocytic

function so it determines the virulence of many bacteria. It also plays a role in attachment of

the organism to mucous membranes.[citation needed]

Flagella

Flagellaare the organelles of cellular mobility. They arise from cytoplasm and extrude through

the cell wall. They are long and thick thread-like appendages, protein in nature. Are most

commonly found in bacteria cells but are found in animal cells as well.

11
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Fimbriae (pili)

They are short and thin hair like filaments, formed of protein called pilin (antigenic).Fimbriae

are responsible for attachment of bacteria to specific receptors of human cell (adherence).

There are special types of pili called (sex pili) involved in conjunction.[citation needed]

Functions

Growth and metabolism

Between successive cell divisions, cells grow through the functioning of cellular metabolism.

Cell metabolism is the process by which individual cells process nutrient molecules. Metabolismhas two distinct divisions:catabolism, in which the cell breaks down complex molecules to

produce energy and reducing power, andanabolism, in which the cell uses energy and reducing

power to construct complex molecules and perform other biological functions. Complex sugars

consumed by the organism can be broken down into a less chemically complex sugar molecule

calledglucose. Once inside the cell, glucose is broken down to make adenosine triphosphate

(ATP), a form of energy, through two different pathways.

The first pathway,glycolysis, requires no oxygen and is referred to asanaerobic metabolism.

Each reaction is designed to produce some hydrogen ions that can then be used to make

energy packets (ATP). In prokaryotes, glycolysis is the only method used for converting energy.

The second pathway, called the Krebs cycle, orcitric acid cycle, occurs inside the mitochondria

and can generate enough ATP to run all the cell functions.

Creation

Cell division involves a single cell (called a mother cell) dividing into two daughter cells. This

leads to growth inmulticellular organisms(the growth oftissue) and to procreation (vegetative

reproduction) inunicellular organisms.
http://en.wikipedia.org/wiki/Fimbriaehttp://en.wikipedia.org/wiki/Fimbriaehttp://en.wikipedia.org/wiki/Fimbriaehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Fermentation_%28biochemistry%29http://en.wikipedia.org/wiki/Fermentation_%28biochemistry%29http://en.wikipedia.org/wiki/Fermentation_%28biochemistry%29http://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Unicellular_organismhttp://en.wikipedia.org/wiki/Unicellular_organismhttp://en.wikipedia.org/wiki/Unicellular_organismhttp://en.wikipedia.org/wiki/Unicellular_organismhttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Vegetative_reproductionhttp://en.wikipedia.org/wiki/Biological_tissuehttp://en.wikipedia.org/wiki/Multicellular_organismhttp://en.wikipedia.org/wiki/Citric_acid_cyclehttp://en.wikipedia.org/wiki/Fermentation_%28biochemistry%29http://en.wikipedia.org/wiki/Glycolysishttp://en.wikipedia.org/wiki/Adenosine_triphosphatehttp://en.wikipedia.org/wiki/Glucosehttp://en.wikipedia.org/wiki/Anabolismhttp://en.wikipedia.org/wiki/Catabolismhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Fimbriae


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Prokaryoticcells divide bybinary fission.Eukaryoticcells usually undergo a process of nuclear

division, calledmitosis, followed by division of the cell, calledcytokinesis. Adiploidcell may also

undergomeiosisto produce haploid cells, usually four.Haploidcells serve asgametesin

multicellular organisms, fusing to form new diploid cells.

DNA replication, or the process of duplicating a cell's genome, is required every time a cell

divides. Replication, like all cellular activities, requires specialized proteins for carrying out the

job.

Protein synthesis

Cells are capable of synthesizing new proteins, which are essential for the modulation and

maintenance of cellular activities. This process involves the formation of new protein molecules

fromamino acidbuilding blocks based on information encoded in DNA/RNA. Protein synthesis

generally consists of two major steps:transcriptionandtranslation.

Transcription is the process where genetic information in DNA is used to produce a

complementary RNA strand. This RNA strand is then processed to givemessenger RNA(mRNA),

which is free to migrate through the cell. mRNA molecules bind to protein-RNA complexes

calledribosomeslocated in thecytosol, where they are translated into polypeptide sequences.

The ribosome mediates the formation of a polypeptide sequence based on the mRNA

sequence. The mRNA sequence directly relates to the polypeptide sequence by binding to

transfer RNA(tRNA) adapter molecules in binding pockets within the ribosome. The new

polypeptide then folds into a functional three-dimensional protein molecule.

14
http://en.wikipedia.org/wiki/Prokaryotehttp://en.wikipedia.org/wiki/Prokaryotehttp://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Mitosishttp://en.wikipedia.org/wiki/Mitosishttp://en.wikipedia.org/wiki/Mitosishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Diploidhttp://en.wikipedia.org/wiki/Diploidhttp://en.wikipedia.org/wiki/Diploidhttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/Haploidhttp://en.wikipedia.org/wiki/Haploidhttp://en.wikipedia.org/wiki/Haploidhttp://en.wikipedia.org/wiki/Gametehttp://en.wikipedia.org/wiki/Gametehttp://en.wikipedia.org/wiki/Gametehttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Translation_%28genetics%29http://en.wikipedia.org/wiki/Translation_%28genetics%29http://en.wikipedia.org/wiki/Translation_%28genetics%29http://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Transfer_RNAhttp://en.wikipedia.org/wiki/Cytosolhttp://en.wikipedia.org/wiki/Ribosomehttp://en.wikipedia.org/wiki/Messenger_RNAhttp://en.wikipedia.org/wiki/Translation_%28genetics%29http://en.wikipedia.org/wiki/Transcription_%28genetics%29http://en.wikipedia.org/wiki/Amino_acidhttp://en.wikipedia.org/wiki/DNA_replicationhttp://en.wikipedia.org/wiki/Gametehttp://en.wikipedia.org/wiki/Haploidhttp://en.wikipedia.org/wiki/Meiosishttp://en.wikipedia.org/wiki/Diploidhttp://en.wikipedia.org/wiki/Cytokinesishttp://en.wikipedia.org/wiki/Mitosishttp://en.wikipedia.org/wiki/Eukaryotehttp://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Prokaryote


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15


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Movement or motility

Cells can move during many processes: such as wound healing, the immune response and

cancer metastasis. For wound healing to occur, white blood cells and cells that ingest bacteria

move to the wound site to kill the microorganisms that cause infection.

At the same time fibroblasts (connective tissue cells) move there to remodel damaged

structures. In the case of tumor development, cells from a primary tumor move away and

spread to other parts of the body. Cell motility involves many receptors, crosslinking, bundling,

binding, adhesion, motor and other proteins.[10]

The process is divided into three steps

protrusion of the leading edge of the cell, adhesion of the leading edge and de-adhesion at the

cell body and rear, and cytoskeletal contraction to pull the cell forward. Each step is driven by

physical forcesgenerated by unique segments of the cytoskeleton

(http://en.wikipedia.org/wiki/Cell_%28biology%29)

16
http://en.wikipedia.org/wiki/Cancer_metastasishttp://en.wikipedia.org/wiki/Cancer_metastasishttp://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-9http://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-9http://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-9http://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-9http://en.wikipedia.org/wiki/Cancer_metastasis


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B. Chemical Composition of Living Cells

All living organisms, from microbes to mammals, are composed of chemical substances from

both the inorganic and organic world, that appear in roughly the same proportions, and

perform the same general tasks. Hydrogen,oxygen, nitrogen, carbon, phosphorus, and sulfur

normally make up more than 99% of the mass of living cells, and when combined in various

ways, form virtually all known organic biomolecules. They are initially utilized in the synthesis of

a small number of building blocks that are, in turn, used in the construction of a vast array of

vital macromolecules (Fig 1-1). There are four general classes of macromolecules within living

cells: nucleic acids,proteins, polysaccharides, and lipids. These compounds, which have

molecular weights ranging from 1 x 103 to 1 x 106, are created through polymerization of

building blocks that have molecular weights in the range of 50 to 150. Although subtle

differences do exist between cells (e.g., erythrocyte, liver, muscle or fat cell), they all generally

contain a greater variety of proteins than any other type of macromolecule, with about 50% of

the solid matter of the cell being protein (15% on a wetweight basis). Cells generally contain

many more protein molecules than DNA molecules, yet DNA is typically the largest biomolecule

in the cell. About 99% of cellular molecules are water molecules, with water normally

accounting for approximately 70% of the total wet-weight of the cell. Although water is

obviously important to the vitality of all living cells, the bulk of our attention is usually focused

on the other 1% of biomolecules. Data in Table 1-1 regarding the chemical composition of the

unicellular Escherichia coli (E. coli), are not greatly different for multicellular organisms,

including mammals. Each E. coli, and similar bacterium, contains a single chromosome,

therefore, it has only one unique DNA molecule. Mammals, however, contain more

chromosomes, and thus have different DNA molecules in the nucleus.


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Nucleic Acids

Nucleic acids are nucleotide polymers (from the Greek word poly, meaning "several", and mer,

meaning "unit"), that store and transmit genetic information. Only 4 different nucleotides are

used in nucleic acid biosynthesis. Genetic information contained in nucleic acids is stored andreplicated in chromosomes, which contain genes (from the Greek word gennan, meaning "to

produce"). A chromosome is a deoxyribonucleic acid (DNA) molecule, and genes are segments

of intact DNA. The total number of genes in any given mammalian cell may total several

thousand. When a cell replicates itself, identical copies of DNA molecules are produced,

therefore the hereditary line of descent is conserved, and the genetic information carried on

DNA is available to direct the occurrence of virtually all chemical reactions within the cell. The

bulk of genetic information carried on DNA provides instructions for the assembly of virtually

every protein molecule within the cell. The flow of information from nucleic acids to protein is

commonly represented as DNA> messenger ribonucleicacid (mRNA)> transfer RNA

(tRNA)>ribosomal RNA (rRNA)> protein, which indicates that the nucleotide sequence in

a gene of DNA specifies the assembly of a nucleotide sequence in an mRNA molecule, which in

turn directs the assembly of the amino acid sequence in protein through a tRNA and rRNA

molecules.

Proteins

Proteins are amino acid polymersresponsiblefor implementing instructions containedwithin

the genetic code. Twenty different amino acids are used to synthesize proteins,about half are

formed as metabolic intermediates,while the remainder must be providedthrough the diet.

The latter group is referred toas "essential" amino acids (see Chapter 3).Each protein formed in

the body, unique in itsown structure and function, participates inprocesses that characterize

the individuality ofcells, tissues, organs, and organ systems. Atypical cell contains thousands of

differentproteins, each with a different function, andmany serve as enzymes that catalyze (or

speed) reactions. Virtually every reaction in aliving cell requires an enzyme. Other proteins

transport different compounds either outsideor inside cells {e.g., lipoproteins and transferring

(an iron-binding protein) in plasma, or bilirubinbindingproteins in liver cells}; some act as


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storage proteins (e.g., myoglobin binds and stores O2 in muscle cells); others as defense

proteins in blood or on the surface of cells (e.g., clotting proteins and immunoglobulins); others

as contractile proteins (e.g., the actin, myosin and troponin of skeletal muscle fibers); and

others are merely structural in nature (e.g., collagen and elastin). Proteins, unlike glycogen and

triglyceride, are usually not synthesized and stored as nonfunctional entities.

Polysaccharides

Polysaccharides are polymers of simple sugars (i.e., monosaccharides). (The term saccharide is

derived from the Greek word sakchar, meaning "sugar or sweetness".) Some polysaccharides

are homogeneous polymers that contain only one kind of sugar (e.g., glycogen), while others

are complex heterogenouspolymers that contain 8-10 types of sugars. In contrast to

heterogenous polymers (e.g., proteins, nucleic acids, and some polysaccharides), homogenous

polymers are considered to be "noninformational". Polysaccharides, therefore, can occur as

functional and structural components of cells (e.g., glycoproteins and glycolipids), or merely as

noninformational storage forms of energy (e.g., glycogen). The 8-10 monosaccharides that

become the building blocks for heterogenous polysaccharides can be synthesized from glucose,

or formed from other metabolic intermediates (see Chapter 20).

Lipids

Lipids (from the Greek word lipos, meaning "fat") are naturally occurring, nonpolar substances

that are mostly insoluble in water (with the exceptions being the short-chain volatile fatty acids

and ketone bodies), yet soluble in nonpolar solvents (like chloroform and ether). They serve as

membrane components (cholesterol, glycolipids and phospholipids), storage forms of energy

(triglycerides), precursors to other important biomolecules (fatty acids), insulation barriers

(neutral fat stores), protective coatings to prevent infection and excessive gain or loss of water,

and some vitamins (A, D, E, and K) and hormones (steroid hormones). Major classes of lipids are

the saturated and unsaturated fatty acids (short, medium, and long-chain), triglycerides,


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lipoproteins {i.e., chylomicrons (CMs), very low density (VLDL), low density (LDL), intermediate

density (IDL), and high density lipoproteins (HDL)}, phospholipids and glycolipids, steroids

(cholesterol, progesterone, etc.), and eicosanoids (prostaglandins, thromboxanes, and

leukotrienes). All lipids can be synthesized from acetyl-CoA, which in turn can be generated

from numerous different sources, including carbohydrates, amino acids, short-chain volatile

fatty acids (e.g., acetate), ketone bodies, and fatty acids. Simple lipids include only those that

are esters of fatty acids and an alcohol (e.g., mono-, di- and triglycerides). Compound lipids

include various materials that contain other substances in addition to an alcohol and fatty acid

(e.g., phosphoacylglycerols, sphingomyelins, and cerebrosides), and derivedlipids include those

that cannot be neatly classified into either of the above (e.g., steroids, eicosanoids, and the fat-

soluble vitamins). Although the study of physiological chemistry emphasizes organic molecules,

the inorganicelements (sometimes subdivided into macrominerals, trace elements, and ultra

trace elements), are also important (see Chapter 48). Several are "essential" nutrients, and

therefore like certain amino acids and unsaturated fattyacids, must be supplied in the diet.

Inorganic elements are typically present in cells as ionic forms, existing as either free ions or

complexed with organic molecules. Many "trace elements" are known to be essential for life,

health, and reproduction, and have well established actions (e.g., cofactors for enzymes, sites

for binding of oxygen (in transport), and structural components of nonenzymaticmacromolecules; see Chapters 48-52). Some investigators have speculated that perhaps all of

the elements on the periodic chart will someday by shown to exhibit physiologic roles in

mammalian life. Because life depends upon chemical reactions, and because most all diseases

in animals are manifestations of abnormalities in biomolecules, chemical reactions, or

biochemical pathways, physiological chemistry has become the language of all basic medical

sciences. A fundamental understanding of this science is therefore needed not only to help

illuminate the origin of disease, but also to help formulate appropriate therapies. The chapterswhich follow were designed, therefore, to assist

the reader in developing a basic rational approach to the practice of veterinary medicine.

(http://www.tetonnm.com/pics/IndependentSamplePages/1-893441-42-3.pdf)


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A.History

1. 16321723:Antonie van Leeuwenhoekteaches himself to grindlenses, builds a

microscopeand drawsprotozoa, such asVorticellafrom rain water, andbacteriafrom his

own mouth.

2. 1665:Robert Hookediscovers cells in cork, then in living plant tissue using an early

microscope.[6]

3. 1839:Theodor SchwannandMatthias Jakob Schleidenelucidate the principle that plants

and animals are made of cells, concluding that cells are a common unit of structure and

development, and thus founding the cell theory.

4. The belief that life forms can occur spontaneously (generatio spontanea) is contradicted

byLouis Pasteur(1822

1895) (althoughFrancesco Redihad performed an experiment in1668 that suggested the same conclusion).

5. 1855:Rudolf Virchowstates that cells always emerge fromcell divisions(omnis cellula

ex cellula).

6. 1931:Ernst Ruskabuilds firsttransmission electron microscope(TEM) at theUniversity

of Berlin. By 1935, he has built an EM with twice the resolution of a light microscope,

revealing previously unresolvable organelles.

7. 1953:WatsonandCrickmade their first announcement on the double-helixstructure for

DNA on February 28.

8. 1981:Lynn Margulispublished Symbiosis in Cell Evolution detailing theendosymbiotic

theory.

B. Chemical Compounds in Living Cells

Indicator : To explain the chemical compound in living cells

Time : 2 X 45

All living organisms, from microbes to mammals,are composed of chemical substances from

both the inorganic and organic world, that appear in roughly the same proportions, and

perform the same general tasks. Of the elements in the living material of cell, hydrogen,
http://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoekhttp://en.wikipedia.org/wiki/Lens_%28optics%29http://en.wikipedia.org/wiki/Lens_%28optics%29http://en.wikipedia.org/wiki/Lens_%28optics%29http://en.wikipedia.org/wiki/Microscopehttp://en.wikipedia.org/wiki/Microscopehttp://en.wikipedia.org/wiki/Protozoahttp://en.wikipedia.org/wiki/Protozoahttp://en.wikipedia.org/wiki/Protozoahttp://en.wikipedia.org/wiki/Vorticellahttp://en.wikipedia.org/wiki/Vorticellahttp://en.wikipedia.org/wiki/Vorticellahttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Robert_Hookehttp://en.wikipedia.org/wiki/Robert_Hookehttp://en.wikipedia.org/wiki/Robert_Hookehttp://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-Hooke-5http://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-Hooke-5http://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-Hooke-5http://en.wikipedia.org/wiki/Theodor_Schwannhttp://en.wikipedia.org/wiki/Theodor_Schwannhttp://en.wikipedia.org/wiki/Theodor_Schwannhttp://en.wikipedia.org/wiki/Matthias_Jakob_Schleidenhttp://en.wikipedia.org/wiki/Matthias_Jakob_Schleidenhttp://en.wikipedia.org/wiki/Matthias_Jakob_Schleidenhttp://en.wikipedia.org/wiki/Abiogenesishttp://en.wikipedia.org/wiki/Abiogenesishttp://en.wikipedia.org/wiki/Abiogenesishttp://en.wikipedia.org/wiki/Louis_Pasteurhttp://en.wikipedia.org/wiki/Louis_Pasteurhttp://en.wikipedia.org/wiki/Louis_Pasteurhttp://en.wikipedia.org/wiki/Francesco_Redihttp://en.wikipedia.org/wiki/Francesco_Redihttp://en.wikipedia.org/wiki/Francesco_Redihttp://en.wikipedia.org/wiki/Rudolf_Virchowhttp://en.wikipedia.org/wiki/Rudolf_Virchowhttp://en.wikipedia.org/wiki/Rudolf_Virchowhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Ernst_Ruskahttp://en.wikipedia.org/wiki/Ernst_Ruskahttp://en.wikipedia.org/wiki/Ernst_Ruskahttp://en.wikipedia.org/wiki/Transmission_electron_microscopehttp://en.wikipedia.org/wiki/Transmission_electron_microscopehttp://en.wikipedia.org/wiki/Transmission_electron_microscopehttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/James_D._Watsonhttp://en.wikipedia.org/wiki/James_D._Watsonhttp://en.wikipedia.org/wiki/James_D._Watsonhttp://en.wikipedia.org/wiki/Francis_Crickhttp://en.wikipedia.org/wiki/Francis_Crickhttp://en.wikipedia.org/wiki/Francis_Crickhttp://en.wikipedia.org/wiki/Helixhttp://en.wikipedia.org/wiki/Helixhttp://en.wikipedia.org/wiki/Helixhttp://en.wikipedia.org/wiki/Lynn_Margulishttp://en.wikipedia.org/wiki/Lynn_Margulishttp://en.wikipedia.org/wiki/Lynn_Margulishttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Endosymbiotic_theoryhttp://en.wikipedia.org/wiki/Lynn_Margulishttp://en.wikipedia.org/wiki/Helixhttp://en.wikipedia.org/wiki/Francis_Crickhttp://en.wikipedia.org/wiki/James_D._Watsonhttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/University_of_Berlinhttp://en.wikipedia.org/wiki/Transmission_electron_microscopehttp://en.wikipedia.org/wiki/Ernst_Ruskahttp://en.wikipedia.org/wiki/Cell_divisionhttp://en.wikipedia.org/wiki/Rudolf_Virchowhttp://en.wikipedia.org/wiki/Francesco_Redihttp://en.wikipedia.org/wiki/Louis_Pasteurhttp://en.wikipedia.org/wiki/Abiogenesishttp://en.wikipedia.org/wiki/Matthias_Jakob_Schleidenhttp://en.wikipedia.org/wiki/Theodor_Schwannhttp://en.wikipedia.org/wiki/Cell_%28biology%29#cite_note-Hooke-5http://en.wikipedia.org/wiki/Robert_Hookehttp://en.wikipedia.org/wiki/Bacteriumhttp://en.wikipedia.org/wiki/Vorticellahttp://en.wikipedia.org/wiki/Protozoahttp://en.wikipedia.org/wiki/Microscopehttp://en.wikipedia.org/wiki/Lens_%28optics%29http://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoek


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oxygen, nitrogen, carbon, are present in the greatest amount. Phosphorus, sulfur,

magnesium, iodine, iron, calcium, sodium, chlorine and potassium are found in smaller

quantities. When combined in various ways, form virtually all known inorganic and organic

biomolecules. There are four general classes of macromolecules within living cells: nucleic

acids,proteins, polysaccharides, and lipids.

They all generally contain a greater variety of proteins than any other type of

macromolecule, with about 50% of the solid matter of the cell being protein (15% on a

wetweight basis). Cells generally contain many more protein molecules than DNA

molecules, yet DNA is typically the largest biomolecule in the cell. About 99% of cellular

molecules are water molecules, with water normallyaccounting for approximately 70% of

the totalwet-weight of the cell. Although water isobviously important to the vitality of all

livingcells, the bulk of our attention is usuallyfocused on the other 1% of biomolecules.

1. Nucleic Acids

Nucleic acids are a group of organic compounds that are essential to life. These are the

compounds that pass hereditary information from one generation to another, making

possible a remarkable continuity of life within the various species of living

things.Genetic information contained in nucleic acids is stored and replicated in

chromosomes, which contain genes. A chromosome is a deoxyribonucleic acid (DNA)

molecule, and genes are segments of intact DNA. The total number of genes in any

given mammalian cell may total several thousand. Nucleic acids are biological molecules

essential for life, and include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

Together with protein , nucleic acids make up the most important macromolecules;

each is found in abundance in all living things, where they function in encoding,

transmitting and expressing genetic information.

2. Proteins


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Many foods contain protein (say: pro-teen), but the best sources are beef, poultry, fish,

eggs, dairy products, nuts, seeds, and legumes like black beans and lentils. Protein builds

up, maintains, and replaces the tissues in your body.Proteins are organic compounds

composed of the elements carbon, hydrogen, oxygen, and nitrogen. Some proteins also

contain sulfur. All proteins are built from small molecular units known as amino acids.

3. Polysaccharides

Polysaccharides are the complex carbohydrates. Carbohydrates are composed of the

elements carbon, hydrogen, and oxygen. Hydrogen and oxygen atoms are usually

present in carbohydrates in the ratio of 2:1. Glucose (C6H12O6) represents the basic

unit of carbohydrate structure. They are made up of chains of monosaccharides (the

sugars) which are linked together by glycosidic bonds, which are formed by the

condensation reaction. The linkage of monosaccharides into chains creates chains of

greatly varying length, ranging from chains of just two monosaccharides, which makes a

disaccharide to the polysaccharides, which consists of many thousands of the sugars.

4. Lipids

The lipids are group of organic compounds that include the fats and fat-like substances.

A lipid molecule contain the elements carbon,hydrogen and oxygen. In lipid molecules

the ratio of hydrogen to oxygen is much greater than 2:1. A lipid molecule is made up of

two basic units : an alcohol usually glycerol and a class of compounds called fatty acids.

Assignment 1.1

a.

Find out the references from other media (internet or books). That

references connective to material about Chemical Compounds in

Living Cells

b. Dont forget you write the web address or the title of book.

c. Where can you find out that chemical substances in the living cell

body ?

d. Explain the chemical compounds in living cells .


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C. Structure and Functions of Living Cells

Indicator :

1. To use microscope for observe cell structure of fresh cell or preserves

cell

2.

To picture cell structure3. To show a part of cell

4. To explain structure and function of cells

Time : 4 x 45

The structure of prokaryotic cell and eukaryotic cell have many different. Prokaryotic

cells include bacteria and blue green algae. Prokaryotic cell do not have nucleus

membrane, so its genetic material is mixed with cytoplasm. But eukaryotic cell has

nucleus membrane so there is a separation between the nucleus and cytoplasm.

Eukaryotic cells can be found in animal and plant cells. Part compiler of animal and plant

cell have some similarities, namely the cell membrane, nucleus, cytoplasm,

cytoskeleton, ribosomes, endoplasmic reticulum, golgy apparatus, lysosomes,

peroxisomes, and mitochondria.

1. Prokaryotic Cell

Assignment 1.2

For more understand of prokaryotic cell, find out sample of the prokaryotic

cells include living things. Take pictures of the living things named. Give

explanation of pictures.


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2. Eukaryotic Cell

Activity 1.1 Observation of cell component

Time : 2 X 45

Purpose : observe at components of cell

Tools and materials :

1. Pencilknife or gillete

2. Spatula or tooth pick

3. Microscope

4. Microscope slide and glass cover

5. Optilab

6.

Computer or Laptop

7. Stem of Manihot utilisima

8. Epidermis of Red onion

9. Membrane epithellium of mucous mouth ( Epithellium

mucosa cavum oris ) or membrane epithellium of intestine

10.Neutral red 1% diluted in distilled water.

Procedures :

1. Make thin across section of the corky or spongy wood of

Manihot utilisima, lengthsection of Red onion epidermis,scrape on the mouth mucous membrane or intestine

membrane with a clean spatula orblunt end of tooth pick.

2. Put down on the microscope slide, then dropped with

neutral red or water

3. Set optilab in the microscope.

4. Observed under a microscope immediately.

5. Connective microscope, optilab with computer.

6. Find out a good picture the epidermis cell of corky or spongy

wood of Manihot utilisima, the epidermis cell of red Allium,

the epithelium cell of mucous or intestine.

7.

Take that cell pictures.Write down what elements.

8. Make a table differences of the three cells named.

Question :

1. What is the name of each structure that you see under the

microscope ? Describe in your paper.

2. What is the function of every specimens structure that you

observe ?


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Eukaryotic cell has a clearly defined nucleus. The cell nucleus is encased by a nuclear

membrane. This nuclear membrane connects wiyh other membranes, such as plasma

membrane and inner cytoplasmic membrane. Basically eukaryotic cell have some

similarity, which consists of : cytoplasm, plasma membrane, nucleus, and cells organells.

Message for you :

You must complete this student work sheet with answer of assignments and question

activity.

Name: Tan Evelyn Tanujayanti

Class: XI IPA 3

Number: 30

Assignment 1.3.

For more understand of eukaryotic cell, find the pictures of plasma

membrane, nucleus and cell organells. Describe the structure of each picture.

the cell, chapter 1 complete

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