ap chapter 6, 7,8 web assignment- page 1please complete these reviews by wednesday, nov. 13 th

AP Chapter 6, 7,8 Web assignment- page 1Please complete these reviews by Wednesday, Nov. 13th . • http://www.biology.arizona.edu/cell_bio/tutorials/cytoskeleton/main.html

• Go to The Biology Project Website—the University of Arizona

• http://www.biology.arizona.edu/DEFAULT.htmlThe Biology Project Department of Biochemistry and Molecular BiophysicsCollege of ScienceThe University of Arizona Revised: July 2004 Contact the Development Team

• http://www.biology.arizona.edu (save this web site—we will refer to it again and you may want to refer to it on your own)

• Go through the following Tutorials, in the Overview and the Problem Set questions listed below questions.

• The Biology Project > Problem Sets & Tutorials

• Cell Biology

• Prokaryotes, Eukaryotes, & Viruses Tutorial : all 5 questions

• Cell Membranes: 1,2,3,4,5 ,7,9,11,12,13,14,15

• , Studying Cells,:all 4

• Cytoskeleton : all 5

• Biochemistry:

• Energy, Enzymes and Catalysts Problem Set: :4,5,7,8,10,11,12,15,16

http://www.biology.arizona.edu/cell_bio/tutorials/cytoskeleton/main.html

http://www.biology.arizona.edu/DEFAULT.html



http://www.biology.arizona.edu/cell_bio/cell_bio.html

http://www.biology.arizona.edu/cell_bio/tutorials/cytoskeleton/main.html

http://library.thinkquest.org/27819/quizes.shtmlYou are to review all items starred at this website-do quizzes for each/review material.• ***ALL--Chapter One: An Introduction to Cells

• Cells and their history

• The meaning of "life"

• The origin of life

• How cells work

• Types of unicellular organisms

• Chapter Two: The Chemistry of Biology

• Elements and atoms

• Molecules and their formation

• Molecular and structural formulas

• Chemical reactions

• Acids, bases, and buffers

• Organic compounds and the importance of carbon

• Different types of organic compounds

• ***Enzymes and coenzymes

• **Factors which affect the efficiency of an enzyme

• **Diffusion

• ***ALL--Chapter Three: Cell Structures

• The cell membrane and the cell wall

• Movement through the cell membrane

• Vacuoles, vesicles, lysosomes, and perixosomes

• The nucleus, nucleolus, and ribosomes

• The endoplasmic reticulum and Golgi bodies

• The mitochondria

• The cytoskeleton

• Cilia, flagella, and pseudopodia

• Plastids

• **ALL LISTED HERE -Chapter Four: Cell Nutrition and Respiration

• Endocytosis and exocytosis

• Energy, exergonic reactions, and endergonic reactions

• How cells store energy: ATP

http://library.thinkquest.org/27819/quizes.shtml

http://library.thinkquest.org/27819/cgi-bin/quiz.cgi?quiz=1_1





































• Another good place to review cells—structures; limitations of cell size; cell theory; and read about energy and enzymes. This material is in the Biology I section .

• The Biology Web.mht

• http://faculty.clintoncc.suny.edu/faculty/michael.gregory/default.htm

• In the “General Biology I “ section—you will find tutorials on cells, cellular transport, energy, enzymes…and lots more—good reading for review

• Recommend doing these Review Questions--(scroll down to the bottom of the page to find these)

• Cells Review Questions

• Membranes Review Questions

• Energy and Enzymes Review Questions

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Ch 7 A Tour of the Cell:

Are Those Our Cells?

Fig. 4.1, p. 50-51

ROBERT HOOKE

Discovery of the Cell• Hooke, discovers

cells.• 1665• viewed cork and

coined the term “cells”.

• Used Light Microscope

•

• Antonie von Leeuwenhoek, Dutch scientist, made more sophisticated microscopes.

• 1675 . Describes living microorganisms.

The Cell Theory

• 150 years after the work of Hooke and Leeuwenhoek, scientists came up with the cell theory.

• Proposed by Schleiden (plants), Schwann (animals), and Virchow(all cells alike).

1. The Cell Theory. Schleiden

• 1838

• Botantist, whom after extensive studies reported that all plants were composed of fundamental units know as cells.

2.The Cell Theory. Schwann

• 1839

• Zoologist who after extensive studies reported that all animals were composed of fundamental units know as cells.

3.The Cell Theory. Virchow

• 1858

• Proposed that all cells came from pre-existing cells.

Discovery Year ScientistNationality Life Span Contribution

• 1665 RobertHooke English1 635-1703

• Coined the term "cell" while looking at the nonliving tissue known as cork.

• 1675 Anton van LeeuwenhoekDutch1 632-1683

• Lens maker who first reported observations of living cells which he called "animicules".

• 183 Robert BrownEnglish 1812-1889

• First to report the discoverey the nucleus of the cell.

• 1838 Matthias Jakob SchleidenGerman 1804 -1881

• Botantist who after extensive studies reported that all plants were composed of fundamental units know as cells.

• 1839 Theodore Schwann German 1810-1882

• Zoologist who after extensive studies reported that all animals were composed of fundamental units know as cells.

• 1858 Rudolf Virchow German 1821-1902

• Proposed that all cells came from pre-existing cells.

http://www.eshl.org/comfort/scientists/schwann.html

Credit for developing Cell Theory is usually given to three scientists, Theodore Schwann, Matthias Jakob Schleiden, and Rudolf Virchow

• Classical Cell Theory

• All plants are made of cells (Schleiden)

• All animals are made of cells (Schwann)

• All cells come from pre-existing cells (Virchow)

http://en.wikipedia.org/wiki/Theodore_Schwann

http://en.wikipedia.org/wiki/Matthias_Jakob_Schleiden




http://en.wikipedia.org/wiki/Rudolf_Virchow

The modern cell theory, one of the fundamental generalizations of biology, holds that:

• All organisms are composed of one or more cells.

• New cells come from pre-existing cells; life-forms today have descended in unbroken continuity from the first primitive cells that arose on earth more than 3.5 billion years ago.

• Hereditary information passes from parent cell to daughter cell.

• The fundamental biochemical reactions of life take place within cells

• The discovery and early study of cells progressed with the invention and improvement of microscopes in the 17th century.

• In a light microscope (LM) visible light passes through the specimen and then through glass lenses.

• The lenses refract light such that the image is magnified into the eye or onto a video screen.

1. Microscopes provide windows to the world of the cell


Fig. 4.3, p. 52

one layerof lipids

one layerof lipids

lipid bilayer

fluid

fluid

• Microscopes vary in magnification and resolving power.

• Magnification is the ratio of an object’s image to its real size.

• Resolving power is a measure of image clarity.

• .


• Minimum resolution of a light microscope is about 2 microns, the size of a small bacterium

• effectively to about 1,000 times

• Unable to resolve organelles


Fig. 7.1

• To resolve smaller structures -electron microscope (EM) are used, which focuses a beam of electrons through the specimen or onto its surface.

• Because resolution is inversely related to wavelength used, electron microscopes with shorter wavelengths than visible light have finer resolution.

• Theoretically, the resolution of a modern EM could reach 0.1 nanometer (nm), but the practical limit is closer to about 2 nm.

• Transmission electron microscopes (TEMs) are used mainly to study the internal ultrastructure of cells.

• A TEM aims an electron beam through a thin section of the specimen.

• The image is focused and magnified by electromagnets.

• To enhance contrast, the thin sections are stained with atoms of heavy metals.


Fig. 7.2a

• Scanning electron microscopes (SEMs) are useful for studying surface structures.

• Image seems three-dimensional.


Fig. 7.2b

• Electron microscopes reveal organelles, but they can only be used on dead cells and they may introduce some artifacts.

• Light microscopes do not have as high a resolution, but they can be used to study live cells.

• Microscopes are a major tool in cytology, the study of cell structures.

• Cytology coupled with biochemistry, the study of molecules and chemical processes in metabolism, developed into modern cell biology.

Advantages and disadvantages of various microscopes.

• The goal of cell fractionation is to separate the major organelles of the cells so that their individual functions can be studied.

2. Cell biologists can isolate organelles to study their functions

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin CummingsFig. 7.3

• Use an ultracentrifuge: 130,000 RPM

1. homogenization, gently disrupting the cell.

2. homogenate is spun in a centrifuge to separate heavier pieces into the pellet while lighter particles remain in the supernatant.

3. Repeat process with resulting supernatant--

• collect subsequently smaller and smaller pellets.

Panoramic View of the Cell:page 112

• Two MAIN types of cells: Eukaryote and Prokaryote.

• Prokaryotes: Bacteria

• Eukaryotes: all other organisms

2 Structurally different kinds of cells• PROKARYOTES

• Bacteria

• Archarbacteria

• No true nucleus

• Nucleoid region

• No membrane-bound organelles

• EUKARYOTES

• Kingdome Protista, Fungi, Plantae, Animalia

• True Nucleus-Nuclear Envelope

• Organelles

Panoramic View of the Cell:

• All cells Have:• plasma membrane

• nucleus OR nuclear region containing chromosomes

• cytosol

• cytoplasm

• ribosomes

• Eukaryotes have organelles and a membrane-bound nucleus.

A Panoramic View of The CellThey Differ in :

• Size

• Prokaryote 1.-10.0 um diameter

• Microplasmas .1- 1.0 um

• Eukaryote 10-100 um

• Complexity: eukaryotes are comparmentalized

Fig. 7.4 The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membrane-enclosed organelles of the eukaryotic cell.

Prokaryote cell—be able to label, briefly ID functions of components—review of earlier material—not in notes packet

• .

Cell Size is limited-Limited by metabolic requirements• Lower limits

• Enough DNA to program metabolic requirements

• Ribosomes, enzymes-for metabolism & reproduction

• Upper Limits• Proportion of Surface Area : Volume

Ratio limits size


Fig. 7.5

Surface Area : Volume Ratio

• As a cell increases in size its volume increases faster than its surface area.

• Smaller objects have a greater ratio of surface area to volume.

• Though a eukaryote cell has 1000 X the volume of a prokaryote—only has 100 X the surface area

Cell Size is Limited

• In most cases, a living thing grows because it produces MORE cells

• An adult simply has more cells than an infant, not simply larger cells.

• WHY more cells, not larger cells?

• Membrane Function…; rate of transport in and out

• How fast exchange occurs depends upon the SURFACE AREA of the cell

• BUT, how quickly food & Waste are made depends on Cell Volume

But not all cells are exactly alike--specialized

Cell Shape and Organization

• Cells are shaped according to their function.

• Ex. Branching nerve cell

Nerve Cell (neuron)

Cellular Compartmentalization & its Significance

• A eukaryotic cell has extensive and elaborate internal membranes, which partition the cell into compartments.

• The barriers created by membranes provide different local environments that facilitate specific metabolic functions.

Internal membranes compartmentalize the functions of a eukaryotic cell


So…Compartmentalization

• Protect Materials

• Permits Multi-tasking

• The general structure of a biological membrane is a double layer of phospholipids with other lipids and diverse proteins.

• Each type of membrane has a unique combination of lipids and proteins for its specific functions.

• For example, those in the membranes of mitochondria function in cellular respiration.



Fig. 7.7


Fig. 7.8

The Nucleus and Ribosomes

1. The nucleus contains a eukaryotic cell’s genetic library

2. Ribosomes build a cell’s proteins

(use the chart on the next page to fill in terms)

• Contains a cell’s genetic library

most of the cell’s DNA

• Nuclear Envelope

Double membrane.

• Nuclear Pores

1. The nucleus


• Nuclear lamina, Network of intermediate filaments on nuclear side;

• Maintain the shape of the nucleus.


Fig. 7.9

• Chromatin: DNA and associated proteins

• In a normal (not dividing) cell they appear as a diffuse mass. (grainy)

• Early in Cell Division, chromosomes condense, forming chromosomes (visible)


• Nucleolus.

• rRNA subunits synthesized here.

• Pass through nuclear pores to the cytoplasm where they combine to form ribosomes.


• Ribosomes contain rRNA and protein.

• A ribosome is composed of two subunits that combine to carry out protein synthesis. (in the cytosol)

2. Ribosomes


Fig. 7.10

Cell types that synthesize large quantities of proteins (e.g., pancreas) have lots.

• Free ribosomes: are suspended in the cytosol and synthesize proteins that function within the cytosol.

• Bound ribosomes, are attached to the outside of the endoplasmic reticulum.

• Synthesize secretory and membranes proteins.

• Example: cells of pancreas-produce and secrete insulin in secretory vessicles.

The Endomembrane System

All eukaryotic cells have within them a

functionally interrelated membrane systemfunctionally interrelated membrane system..

• ..either in direct contact or connected via transfer of vesicles ( sacs of membrane )

The Endomembrane system Consists of:

• nuclear envelope

• ER

• Golgi apparatus

• vesicles

• plasma membrane.

Traffic Flow in the Endomembrane System

•plasma membrane.

• secretory vesicles

• Golgi apparatus

•ER

nuclear envelope

• Transport vessicle

exocytosis

• The ER membrane is continuous with the nuclear envelope

• It accounts for half the membranes in a eukaryotic cell.

• Includes membranous tubules and flattened sacs called cisternae.

• The membrane encloses a compartment—the cisternal space

• ..

The endoplasmic reticulum

SMOOTH ER• No ribosomes

• Synthesis of lipids, including oils, phospholipids, and steroids.

• Calcium ion storage (muscle cells)

• Detoxification of drugs, alcohol. and poisons.

• Some cell types have lots!!

• Frequent exposure leads to the proliferation of smooth ER, increasing tolerance to the target and other drugs.

• .

Rough ER

• bound ribosomes

• Synthesis of membrane (all membranes) proteins and secretory proteins

• Modification/folding of peptides

• Synthesis of phospholipids


Fig. 7.12

The Golgi apparatus

Flattened membranous sacs - cisternae – resembles a stack of pita bread.

•.

• Many transport vesicles from the ER travel to the Golgi apparatus for modification of their contents.

• Especially extensive in

• cells specialized for

secretion

The Golgi apparatus Manufacturing, warehousing, sorting, and shipping. :


• Cis Face –closest to ER—vessicles that bud from the ER (Transport vessicles )are received here.

• Trans Face –nearest to the plasma membrane

• Actual Functions

• Alters membrane phospholipids and oligosaccharides

Targets products—by adding phosphate groups or oligosaccharides (molecular ID tags)

• Packages materials into transport vesicles.


Has a receiving end and a shipping end…The 2 faces of the Golgi Apparatus

• Membrane-enclosed sacs of hydrolytic enzymes that digests all major classes of macromolecules.

• These enzymes work best at pH 5.

3. Lysosomes—are digestive compartments

The benefit of the lysosome membrane:1. protects cytosol from these hydrolytic enzymes

2. Maintains the optimal pH within by pumping H+ ions inward.

• Massive leakage from lysosomes can destroy a cell by autodigestion.


• The lysosomal enzymes and membrane are synthesized by rough ER and then transferred to the Golgi.


Fig. 7.14


Fig. 7.13b

• Lysosomes can fuse with (then digest) :

• A) food vacuoles, formed when a food item is brought into the cell by phagocytosis.

• B) another organelle or part of the cytosol.

• This recycling, or autophagy, renews the cell.

• Critical role in the programmed destruction of cells in multicellular organisms.

• Allows reconstruction during the developmental process & metamorphosis.

• Several inherited diseases affect lysosomal metabolism.

• These individuals lack a functioning version of a normal hydrolytic enzyme.

• Lysosomes are engorged with indigestable substrates.

• These diseases include Pompe’s disease in the liver and Tay-Sachs disease in the brain


• Vesicles and vacuoles (larger versions) are membrane-bound sacs with varied functions.

• Food vacuoles, from phagocytosis, fuse with lysosomes.

• Contractile vacuoles, found in freshwater protists, pump excess water out of the cell.

• Central vacuoles are found in many mature plant cells.

4. Vacuoles


• Tonoplast-membrane.

• Functions :

stockpiling proteins or inorganic ions

depositing metabolic byproducts

storing pigments

storing defensive compounds against herbivores.

• It also increases surface to volume ratio for the whole cell.


Central Vacuole


Fig. 7.15

• WRAPPING IT UP…

• The endomembrane system plays a key role in the synthesis (and hydrolysis) of macromolecules in the cell.

• The various components modify macromolecules for their various functions.


Fig. 7.16

Other Membranous Organelles

1. Mitochondria and chloroplasts

main energy transformers of cells

2. Peroxisomes

generate and degrade H2O2 in performing various metabolic

functions

• CHLOROPLASTS

• Type of plastid

• Three functional compartments

• Intermembrane Space

• Stroma-fluid filled

• Thylakoid Space-enclosed by thylakoid membrane

(chlorophyll embedded here)

• Within the thylakoid membrane (sacs)

• MITOCHONDRIA

• Cellular Respiration-catabolic; Oxygen requiring

• Number in Cell correlates w/ cell’s metabolic activity

• Outer membrane-smooth

• Inner membrane highly folded

• Cristae-increase surface area for C.R.

• Inneremebrane space

• Mitochondrial Matrix-fluid filled space with DNA, ribosomes, enzymes

• Energy transformers

• Not part of Endommbrane system

• Double membranes

• Membrane syn. on free ribosomes

• Ribosomes

• Some DNA

•grow and reproduce

as semiautonomous organelles.

• Mitochondria

• are the sites of cellular respiration

• generate ATP from the catabolism of sugars, fats, and other fuels in the presence of oxygen.

• Chloroplasts

• found in plants and eukaryotic algae, are the sites of photosynthesis.

Mitochondria and chloroplasts


• Energy transformers

• Not part of Endommbrane system


• Membrane syn. on free ribosomes

• Ribosomes

• Some DNA

Plastids: generalized class of plant & algal structures

• 1. Amyloplasts store starch in roots and tubers.

• 2. Chromoplasts store pigments for fruits and flowers.

• 3. The chloroplast produces sugar via photosynthesis.

• chlorophyll.

• mostly found in leaves of plants & algae.



• http://library.thinkquest.org/27819/quizes.shtml

• ..\..\all biology\Reference\Quizzes think quest.mht

• ..\..\all biology\Reference\Library of Crop Technology Lessons.mht

• ..\..\all biology\Reference\Quizzes.htm

http://library.thinkquest.org/27819/quizes.shtml

• Chapter One: An Introduction to Cells

• Cells and their history

• The meaning of "life"

• The origin of life

• How cells work

• Types of unicellular organisms

• Chapter Two: The Chemistry of Biology

• Elements and atoms

• Molecules and their formation

• Molecular and structural formulas

• Chemical reactions

• Acids, bases, and buffers

• Organic compounds and the importance of carbon

• Different types of organic compounds

• Enzymes and coenzymes

• Factors which affect the efficiency of an enzyme

• Diffusion

• Chapter Three: Cell Structures









• Plastids

• Chapter Four: Cell Nutrition and Respiration




• Glycolysis

• Anaerobic processes

• The Krebs cycle and electron transport chain

• Chemiosmosis

• Energy yield for aerobic respiration

• Overview of photosynthesis

• Noncyclic electron flow and the Calvin cycle

• Chapter Five: Cell Reproduction

• Organization of DNA

• Prokaryotic cell division

• The cell cycle

• Mitosis

• Cytokinesis

• Chapter Six: DNA, RNA, and Protein Synthesis

• Early hypotheses regarding the genetic material

• The famous DNA experiments

• DNA's chemical composition and structure

• The packing of DNA in eukaryotes

• DNA replication

• Transcription of RNA

• Types of RNA and the mRNA code

• Translation

• Mutations

• Chapter Seven: The Classification of Unicellular Organisms

• General classification of organisms

• Spirochetes, Myxobacteria, and Cyanobacteria

• Algae

• Euglenas

• Chrysophytes and Pyrrophytes

• Protozoa

• Phyla Mastigophora and Sarcodina

• Phyla Sporozoa and Ciliophora

• Chapter Three: Cell Structures









• Plastids

• Cytokinesis




































































































• Glycolysis



• Chemiosmosis







• The cell cycle

• Mitosis





• Glycolysis



• Chemiosmosis







• The cell cycle

• Mitosis











































• CHLOROPLASTS

• Double outer membrane

• Inner membrane-in the form of flattened sacs—thylakoids

• Grana –stacks of thylakoids

• Thylokoid space—within the thylokoid

• stroma—fluid OUTSIDE the thylokoids

• contains DNA, ribosomes, and enzymes for part of photosynthesis.



Fig. 7.18

• Mitochondria and chloroplasts are mobile and move around the cell along tracks in the cytoskeleton.


• Function: To rid the body of toxic substances

• break fatty acids down to smaller molecules that are transported to mitochondria for fuel.

• Others detoxify alcohol and other harmful compounds.

• In germinating seeds, glyoxysomes, convert lipids to sugars,

• Peroxisomes contain enzymes that transfer hydrogen from various substrates to oxygen, producing hydrogen peroxide

• RH 2 + O 2 oxidase R + H 2 O 2

• H2O2 is a poison, but the peroxisme has another enzyme that converts H2O2 to water.

• 2H 2 O 2 catalase H 2 O + O 2

Peroxisomes-plants and animals-catalyze production and breakdown of peroxide.

Peroxisome Disorders-PRINT TO DISTRIBUTE

• Most involve mutant versions of one or another of the enzymes found within peroxisomes.

• Example: X-linked adrenoleukodystrophy (X-ALD). This disorder results from a failure to metabolize fatty acids properly. LCFA accumulate in the brain. One result is deterioration of the myelin sheaths of neurons. The disorder occurs in young boys because the gene is X-linked. An attempt to find an effective treatment was the subject of the 1992 film Lorenzo's Oil.

• A few diseases result from failure to produce functional peroxisomes. Example: Zellweger syndrome. This disorder results from the inheritance of two mutant genes for one of the receptors (PXR1) needed to import proteins into the peroxisome

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/ExcitableCells.html#myelin

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SexChromosomes.html#x-linkage

The Cytoskeleton

1. Providing structural support to the cell

2. Functions in cell motility and regulation

3. It’s dynamic

• Network of fibers extending throughout the cytoplasm.

• Oganizes the structures and activities of the cell.


Fig. 7.20

• The cytoskeleton provides mechanical support and maintains shape of the cell.

• The fibers act like a geodesic dome to stabilize a balance between opposing forces.

• The cytoskeleton provides anchorage for many organelles and cytosolic enzymes.

• The cytoskeleton is dynamic, dismantling in one part and reassembling in another to change cell shape.

1. Providing structural support to the cell, the cytoskeleton also functions in cell motility and regulation


• The cytoskeleton also plays a major role in cell motility.

• This involves both changes in cell location and limited movements of parts of the cell.

• The cytoskeleton interacts with motor proteins.

• In cilia and flagella motor proteins pull components of the cytoskeleton past each other.

• This is also true in muscle cells.


Fig. 7.21a

• Three main types of fibers in the cytoskeleton:

• microtubules, microfilaments, and intermediate filaments.


• Membranes Review Questions

• Describe the structure of a phospholipid molecule. [answer]

• Define these terms: hydrophobic, hydrophilic.

• Draw a phospholipid bilayer and label the hydrophobic and hydrophilic regions. Show where proteins are located. [answer]

• Define and describe the following: diffusion, osmosis.

• Explain why membranes are relatively impermeable to water-soluble molecules. [answer]

• Explain how turgor pressure is maintained in plant cells.

• Explain what will happen to a plant cell when it is placed in each of the following kinds of solutions: isotonic, hypertonic, hypotonic.

• Explain what will happen to a red blood cell that is placed in each of the following kinds of solutions: isotonic, hypertonic, hypotonic.

• Describe facilitated diffusion, active transport, and cotransport.

• Tell whether the pumps used in active transport are carbohydrate, lipid, protein, or nucleic acid. [answer]

• The sodium-potassium pump is an example of _______ transport. [answer]

• Describe the operation of the sodium-potassium pump. [answer]

• Define and describe each of the following: Endocytosis, Phagocytosis, Pinocytosis, Exocytosis

• Name the functions of proteins in a plasma membrane. [answer]

•

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Phospholipids

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/biochemi.htm#Hydrophilic

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/biochemi.htm#Hydrophilic

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Proteins%20Embedded%20in%20the%20Membrane

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Diffusion

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Osmosis

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Membranes%20are%20Semipermeable

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Hypotonic

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Hypotonic

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Isotonic

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Membranes/membrane.htm#Hypertonic%20solution

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Review%20Questions%20-%20Lecture/energy.htm

• Energy and Enzymes Review Questions

• State the function of ATP. [answer]

• Tell whether ATP is a carbohydrate, lipid, protein, or nucleic acid. [answer]

• Discuss the meaning of the first law of thermodynamics. [answer]

• Tell how enzymes affect the energy of activation of a reaction.

• Making ATP from ADP + Pi is called __________. [answer]

• The process of making ATP in the cytosol is called __________. [answer]

• The process of making ATP in the mitochondria or chloroplast is called __________. [answer]

• Briefly explain how enzymes work. Drawings may be helpful. [answer]

• Discuss the nature of an enzyme-substrate complex. Do the enzymes bond with the substrate? [answer]

• Explain why enzymes can be reused many times. [answer]

• ATP is made from _______. [answer]

• List factors that affect the rate of an enzyme reaction. [answer]

• Define oxidation and reduction. [answer]

• Give an example of an oxidation/reduction reaction. [answer]

• Discuss allosteric inhibition of enzymes. [answer]

• What are coenzymes? [answer]

• Explain why an enzyme is specific for a particular substrate. [answer]

• What is a catalyst? Are enzymes catalysts? Are they organic molecules? [answer]

• The energy needed to initiate a chemical reaction is called _________ energy. [answer]

• Discuss how an enzyme may place stress on the bonds of a substrate. [answer]

• Discuss the role of a cofactor in an enzyme-catalyzed reaction. [answer]

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/biochemi.htm#ATP

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#ATP%20is%20a%20Nucleotide

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Laws%20of%20Thermodynamics

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Formation%20of%20ATP

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Substrate-Level%20Phosphorylation

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Chemiosmotic%20Phosphorylation

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Induced-Fit%20Theory



http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#ATP%20is%20a%20Nucleotide

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Conditions%20that%20Affect%20Enzymatic%20Reactions

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Oxidation%20and%20Reduction

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Electron%20Carriers%20in%20Cellular%20Respiration

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Noncompetitive%20Inhibition

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Coenzymes


http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Enzymes

http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Catabolic%20and%20Anabolic%20Reactions


http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Energy/energy.htm#Coenzymes

• Structure:

• thickest fibers

• hollow rods about 25 microns in diameter.

• globular protein, tubulin

• they grow or shrink as more tubulin molecules are added or removed.

• In plant cells, microtubules are created at many sites scattered through the cell.

• In animal cells, the microtubules originate at the centrosome.

1. Microtubules

1. Microtubules

• Functions: (primarily in movement)• They move chromosomes during cell division.

• Cell motility (cilia and flagella)

• Tracks for organelle movement

• Cellular support/compression-resistant “girders”


Fig. 7.22

Microtubules grow out of a Centrosome

• A region of the cell near nucleus

• Within each centrosome (animal cells) is a pair of..

• Centrioles

• Made of microtubules—nine sets of triplets arranged in a ring.

• Help organize microtubules for cell division

• carrying organelles to their destination. ATP powers the motors.

• Motor molecules attach to receptors on organelles, walk the organelle along.

• Vesicles also travel on these “monorails’ provided by the cytoskeleton.

Microtubules function as tracks that guide motor proteins

• Function for movement in water (sperm cells) or move water over surface ( cells in windpipe).

• Both similar thickness


Microtubules and: Cilia & Flagella-microtubules provide the structural support

• Both cilia and flagella have

• Core of microtubules sheathed by the plasma membrane.

• Nine doublets of microtubules arranged around a pair at the center, the “9 + 2” pattern.

• Flexible “wheels” of proteins connect outer doublets to each other and to the core (restricts movement somewhat)

• The outer doublets are also connected by motor proteins of dynein.

• Anchored in the cell by a basal body, whose structure is identical to a centriole.



Fig. 7.24

How they differ

• Cilia

• usually occur in large numbers on the cell surface.

• Shorter

• Back forth—oar-like. —moves perpendicular to the axis of the cilium

• Flagella• 1 or 2 per cell-usually

• Longer

• Beating pattern-smooth, undulating (snakelike)-


• A flagellum has an undulatory movement—like a snake.

• Force is generated parallel to the flagellum’s axis.


Fig. 7.23a


Fig. 7.23b

• Cilia move more like oars with alternating power and recovery strokes.

• They generate force perpendicular to the cilia’s axis.

• The bending of cilia and flagella is driven by the arms of a motor protein, dynein.

• Addition to dynein of a phosphate group from ATP and its removal causes conformation changes in the protein.

• Dynein arms alternately grab, move, and release the outer microtubules.

• Protein cross-links limit sliding and the force is expressed as bending.


Fig. 7.25

Dynein”walking”

Prokaryote flagella

• Filamentous protein structures composed of flagellin

attached to the cell surface.

• much thinner

• lack the typical 9 + 2 arrangement of microtubules

• Rotary movement

EXTRA-DO NOT “NEED TO KNOW” Other cellular cilia functions

• Lack of functional cilia in mammalian Fallopian tubes can cause ectopic pregnancy. A fertilized ovum may not reach the uterus if the cilia are unable to move it there. In such a case, the ovum will implant in the Fallopian tubes, causing a tubal pregnancy, the most common form of ectopic pregnancy.

http://en.wikipedia.org/wiki/Fallopian_tubes

http://en.wikipedia.org/wiki/Ectopic_pregnancy

http://en.wikipedia.org/wiki/Ectopic_pregnancy

http://en.wikipedia.org/wiki/Ovum

http://en.wikipedia.org/wiki/Uterus

http://en.wikipedia.org/wiki/Tubal_pregnancy

http://en.wikipedia.org/wiki/Tubal_pregnancy

• Structure:

• the thinnest (7 nm)

• Actin filaments are long, thin fibers composed of 2 chains wrapped around each other

• Functions

• Microfilaments are designed to bear tension (pulling forces)-maintain cell shape.

• With other proteins, they form a three-dimensional network just inside the plasma membrane.

• Muscle contraction

• Cytoplasmic streaming

• The chloroplasts of plant cells move (circulate) by following actin filaments, a process called cytoplasmic streaming.

• Cleavage-furrow formation

2. Microfilaments (actin filaments)


Fig. 7.26 The shape of the microvilli in this intestinal cell are supported by microfilaments, anchored to a network of intermediate filaments.

Microvilli

• Bundles of microfilaments

make up the core of microvilli

(delicate projections that

increase a cell’s surface area)

small intestine,

• In muscle cells, thousands of actin filaments are arranged parallel to one another.

• Thicker filaments composed of a motor protein, myosin, interdigitate with the thinner actin fibers.

• Myosin molecules walk along the actin filament, pulling stacks of actin fibers together and shortening the cell.


Fig. 7.21a

• In other cells, these actin-myosin aggregates are less organized but still cause localized contraction.

• A contracting belt of microfilaments divides the cytoplasm of animal cells during cell division.

• Localized contraction also drives amoeboid movement.

• Pseudopodia, cellular extensions, extend and contract through the reversible assembly and contraction of actin subunits into microfilaments.


Fig. 7.21b

• In plant cells (and others), actin-myosin interactions and sol-gel transformations drive cytoplasmic streaming.

• This creates a circular flow of cytoplasm in the cell.

• This speeds the distribution of materials within the cell.


Fig. 7.21c

• Structure

• Family of Keratin protein subunits (but varies)

• Intermediate in size (8-12 nm)

• Function

• Specialized for bearing tension.

• Reinforce cell shape and fix organelle location.

• Nuclear lamina

• More permanent fixtures of the cytoskeleton than are the other two classes.

• .


Fig. 7.26

3. Intermediate filaments,

Examples of the cytoskeleton in epithelial cells

• In the epithelial (skin) cells of the intestine, all three types of fibers are present. Microfilaments

project into the villi, giving shape to the cell surface. Microtubules grow out of the centrosome

to the cell periphery. Intermediate filaments connect adjacent cells through desmosomes.


1. Plant cells are encased by cell walls

2. The extracellular matrix (ECM) of animal cells functions in support,

adhesion, movement, and regulation

3. Intercellular junctions help integrate cells into higher levels of structure and

function

4. The cell is a living unit greater than the sum of its parts

Cell Surfaces and Junctions

• protects the cell

• maintains its shape

• prevents excessive uptake of water.

• Regulatory

• Permits water, ions, small proteins (most plant hormones are small)

• Surface receptors

• Supports the plant against the force of gravity.

1. Cell walls in plants


• Thicker than plasma membrane-though thickness and chemical composition of cell walls differs from species to species and among cell types.

• Microfibrils of cellulose embedded in a matrix of proteins and other polysaccharides.

• This is like steel-reinforced concrete or fiberglass.


Fig. 7.28

Plant Cell Walls• Young plant lays down a thin, flexible Primary Cell

Wall

• Middle Lamella:

• Pectin-glues cells together

• (pectin thickens jelly and jam)

• At maturity, to strengthen its wall, adds a Secondary Cell Wall between the Plasma Membrane and the Primary wall, deposited in several laminated layers.

• A mature cell wall consists of a primary cell wall, a middle lamella with sticky polysaccharides (pectin) that holds cell together, and layers of secondary cell wall.

• Composed mostly- a variety of glycoproteins.

• Collagen fibers are the most abundant-- strong; these are embedded in a network of proteoglycans.

• Collagen accounts for half of the protein in the human body

• In some cells, Integrins (transmembtane proteins) connect the ECM to the cytoskeleton—mechanical signaling.

• ECM Fibronectin Intergin Cytoskeleton

2. The extracellular matrix (ECM) of animal cells functions in support, adhesion, movement, and regulation


• Integrins are bound to the ECM on one side and to the microfilaments of the cytosol side. This linkage linkage can transmit stimuli between the external environment and its interior.


Fig. 7.29

• Neighboring cells in tissues, organs, or organ systems often adhere, interact, and communicate through direct physical contact.

• 1.Plant cells are perforated with plasmodesmata, channels allowing cysotol to pass between cells.

3. Intercellular junctions help integrate cells into higher levels of structure and function


Fig. 7.28 inset

• 2. Animal have 3 main types of intercellular links: tight junctions, desmosomes, and gap junctions.

• 1. In tight junctions, membranes of adjacent cells are fused, forming continuous belts around cells.

• This prevents leakage of extracellular fluid.


Fig. 7.30

• Desmosomes (or anchoring junctions) fasten cells together into strong sheets, much like rivets.

• Intermediate filaments of keratin reinforce


• 3. Gap junctions (or communicating junctions) provide cytoplasmic channels between adjacent cells.

• Most like plant plasmodermata

• Salt ions, sugar, amino acids, and

other small molecules can pass(not proteins)

• Especially important in:

• embryos, facilitate chemical

communication during development.

• heart tissue-coordinate contraction

• While the cell has many structures that have specific functions, they must work together.

• For example, macrophages use actin filaments to move and extend pseudopodia, capturing their prey, bacteria.

• Food vacuoles are digested by lysosomes, a product of the endomembrane system of ER and Golgi.

4. A cell is a living unit greater than the sum of its parts


• The enzymes of the lysosomes and proteins of the cytoskeleton are synthesized at the ribosomes.

• The information for these proteins comes from genetic messages sent by DNA in the nucleus.

• All of these processes require energy in the form of ATP, most of which is supplied by the mitochondria.

• A cell is a living unit greater than the sum of its parts.


Fig. 7.31

ap chapter 6, 7,8 web assignment- page 1please complete these reviews by wednesday, nov. 13 th

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