Download - Cell Theory and Cell Basics 2014
Antonie van LeeuwenhoekThe first man to witness a live cell under a microscope was Antonie van Leeuwenhoek, who in 1674 described the algae Spirogyra and named the moving organisms animalcules, meaning “little animals.”
In 1678, Antoni van Leeuwenhook reported that he had observed “little animals” -- protozoa -- through a microscope, he also called them “little beasties.”
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Robert HookeThe cell was first discovered by Robert Hooke in 1665. He observed dead cork (cork comes from the bark of a cork oak0 tree) and named the structures he observed “cells” which means small room.
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Theodor SchwannMatthias Jakob Schleiden Rudolf Virchow In 1839, Schwann and Schleiden suggested that cells were the basic unit of life.
In 1858, Rudolf Virchow concluded that all cells come from pre-existing cells, thus completing the classical cell theory.
Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow are credited with developing cell theory.
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Schwann
Schleiden
Virchow
Traditional rules of the Cell Theory 1. All life forms are made
from one or more cells.
2. Cells only arise from pre-existing cells.
3. The cell is the smallest form of life.
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Modern rules of the Cell Theory — 1
1 All known living things are made up of cells. All organisms are made up of one or more cells.
2 The cell is structural & functional unit of all living things.
3 All cells come from pre-existing cells by division. (Spontaneous Generation does not occur).
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Modern rules of the Cell Theory — 2
4 Cells contains hereditary information (DNA) which is passed from cell to cell during cell division.
5 All cells are basically the same in chemical composition.
6 All energy flow (metabolism & biochemistry) of life occurs within cells.
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Living?Characteristics of Life
HomeostasisOrganizationMetabolismGrowthAdaptationResponse to stimuliReproduceHereditary molecule is DNA
Viruses Bacteria are living organisms but
opinions vary on whether viruses are.
A virus is an organic structures that interacts with living organisms.
It does show characteristics of life such as having genes, evolving by natural selection and reproducing by creating multiple copies of themselves through self-assembly.
But viruses don't have a cellular structure or their own metabolism; they need a host cell to reproduce.
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Viruses Viruses are the smallest and
simplest life form known. They are 10 to 100 times smaller than bacteria.
Viruses must have a living host - like a plant or animal - to multiply.
Viruses are intracellular organisms (they infiltrate the host cell and live inside the cell). They change the host cell's genetic material from its normal function to producing the virus itself.
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ProkaryotesProkaryotes
The prokaryotes are a group of organisms that lack a cell nucleus, or any other membrane-bound organelles.
They differ from the eukaryotes, which have a cell nucleus.
Most are unicellular, but a few prokaryotes such as myxobacteria have multicellular stages in their life cycles.
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Prokaryotes The prokaryotes are divided into
two domains: the bacteria and the archaea.
Archaea were recognized as a domain of life in 1990.
These organisms were originally thought to live only in inhospitable conditions such as extremes of temperature, pH, and radiation but have since been found in all types of habitats.
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Eukaryotes
Greek Meaning
eu good, noble, true
karyon nut, kernel
The presence of a nucleus gives eukaryotes their name.
Eukaryotic
A eukaryotic is an organism whose cells contain complex structures inside the membranes.
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The most important membrane-bound structure setting eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried.
Most eukaryotic cells also contain other membrane-bound organelles such as mitochondria, chloroplasts and the Golgi apparatus.
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Eukaryotic
NucleusThe “control center,”
it maintain the integrity of these genes and to control the activities of the cell by regulating gene expression.
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Cell Membrane or Plasma Membrane
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Function:
It separates the interior of a cell from the outside environment. The cell membrane surrounds all cells and it is semi-permeable, controlling the movement of substances in and out of cells.
Cell Wall
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Provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell. They are found in plants, bacteria, fungi, algae, and some archaea.
Rough Endoplasmic Reticulum (RER)
Ribosome to bind to
the RER and pass the
new protein through
the ER membrane.
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Smooth Endoplasmic Reticulum (SER) Several metabolic processes,
including synthesis of lipids and
steroids, metabolism of
carbohydrates, regulation of calcium
concentration, drug detoxification,
attachment of receptors on cell
membrane proteins, and steroid
metabolism.
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Golgi apparatusProcesses and packages
macromolecules, such as
proteins and lipids, after their
synthesis and before they
make their way to their
destination; it is particularly
important in the processing of
proteins for secretion
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Cytoskeleton It is a dynamic structure that
maintains cell shape, protects the
cell, enables cellular motion (using
structures such as flagella, cilia and
lamellipodia), and plays important
roles in both intracellular transport
(the movement of vesicles and
organelles, for example) and cellular
division.
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Mitochondria Generate most of the cell’s supply of
adenosine triphosphate (ATP), used
as a source of chemical energy. In
addition to supplying cellular
energy, they are involved in a range
of other processes, such as signaling,
cellular differentiation, cell death, as
well as the control of the cell cycle
and cell growth.
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Vacuole The function and importance of vacuoles varies greatly
according to the type of cell in which they are present, having much greater prominence in the cells of plants, fungi and certain protists than those of animals and bacteria. In general, the functions of the vacuole include: Isolating materials that might be harmful or a threat to
the cell Containing waste products Maintaining internal hydrostatic pressure or turgor
within the cell Maintaining an acidic internal pH Containing small molecules Exporting unwanted substances from the cell Allows plants to support structures such as leaves and
flowers due to the pressure of the central vacuole
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Cytoplasm Are filled with liquid that is kept separate
from the rest of the cytoplasm by
biological membranes. The cytoplasm is
the site where most cellular activities
occur, such as many metabolic pathways
like glycolysis, and processes such as cell
division.
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Lysosome
Lysosomes digest
excess or worn-out
organelles, food
particles, and
engulfed viruses or
bacteria.
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Centrioles within Centrosome These are involved in the organization of
the mitotic spindle and in the completion
of cytokinesis (the process in which the
cytoplasm of a single eukaryotic cell is
divided to form two daughter cells).
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Chloroplasts
Chloroplasts capture light
energy to conserve free
energy in the form of ATP
and reduce NADP to
NADPH through a complex
set of processes called
photosynthesis.
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OrganellesPlantsPlants
Cell MembraneCell wallsChloroplastsVacuoles LysosomesGolgi BodiesMitochondriaEndoplasmic Reticulum
(ER)Ribosomes
AnimalsAnimals
Cell MembraneCentrioles (used in cellular
reproduction) Vacuoles LysosomesGolgi BodiesMitochondriaEndoplasmic Reticulum
(ER)Ribosomes
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Cell Theory RapListen close to the story I tell.
It’s the rapping story of the living cell.
It’s a happy tune that’s sort of cheery.
About a real tough topic called the cell theory.
All animals, plants, and protists too,
Are made of cells with different jobs to do.
They’re the basic units of all organisms,
And I hope by now you got the rhythm.
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It all started with one dude named Hooke.
Who at some cork cells took a look.
He used a scope and took his time.
‘Cause a cell is small and thinner than a dime.
Say 1, 2, 3, 4,
Are you ready to learn some more?
The animal cell has many parts,
And you must know each one by heart.
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Like the farmer man in the dell.
The nucleus controls the cell.
its gives the orders -- kind of like a brain.
And it’s protected by a nuclear membrane.
Around the cell, you’ll find another “skin,”
The cellular membrane holds the whole cell in
But its job isn’t simple there’s no doubt,
It lets some particles go in and out.
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Now please don’t lose your science enthusiasm,
Listen to the story of the cytoplasm.
All around the cell this thick fluid does go,
But in the nucleus it will not flow.
And don’t forget those ribosomes -
This is where proteins come from.
These protein factories are so small, you’ll agree,
You need an electron microscope to see.
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Just when you thought you weren’t having any fun,
Along comes teh endoplasmic reticulum.
These tubelike structures serve as a track,
To carry stuff to the membrane and back.
Now have you ever seen any doughnuts without holes?
In a cell, they’re called vacuoles.
They’re filled with stuff like H2O
And they carry food so the cell can grow.
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