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Cells

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Title: BIO 156 CH 3 Cells Author: revie Last modified by: brewster Created Date: 5/21/2003 9:19:32 PM Document presentation format: On-screen Show Company – PowerPoint PPT presentation

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Title: Cells


1
Cells
  • Chapter 3
  • Bio 156
  • Fall 2006

2
What is the Cell Theory?
  • All organisms are made of cells.
  • The cell is the smallest unit of life.
  • New cells come from pre-existing cells.

3
What are microscopes? tools used to view cells
  • Compound light microscope light rays focused by
    lenses, viewed by the eye, magnifies up to 1000X

4
Dissecting microscope
  • For observing surface details of objects,
    magnifies up to 30X

Penny
5
Electron microscopes
  • For viewing details, magnifies 1,000,000X

TEM
Surface of a cell, cilia
6
How are cells classified? according to their
internal organization?
  • What structures do all cells have?
  • Cell or plasma membranes living phospholipid
    bilayer and associated proteins

7
Internal organization of cells cont..
  • Plant cells also have a rigid cell wall made
    of cellulose
  • Cytoplasm a semifluid gel inside the cell that
    contain cell contents

8
What are Eukaryotic Cells? Have a true
nucleus, plant and animal cells
  • What are organelles? "little organ", cellular
    structures that perform specific functions
  • What does the nucleus do? control center of the
    cell

9
What are prokaryotic cells? before" the
nucleus (bacteria)
Bacillus polymyxa
  • DNA single circular DNA in a nuceloid region
  • Ribosomes enzymes that synthesize proteins
  • Cell membrane regulates transport in/out of the
    cell
  • Cell wall for strength, may have a capsule or
    slime layer

10
How does cell structure reflect cell function?
  • Simple cuboidal epithelium (400x) is made up of
    one layer of cube-shaped cells.  These cells
    frequently make up the tubes of your body.

11
How does cell structure reflect cell function..
  • Blood Cells
  • Why do you think Red Blood Cells dont have a
    nucleus and White Blood Cells do?
  • (hint think about their functions)

12
How does cell structure reflect cell function
  • Skeletal muscle (400x) is striated
  • What is the function of these cells?
  • Why do you think these are long cells?

http//www.mhhe.com/biosci/ap/histology_mh/skmuscl
s.jpg
13
How does cell structure reflectcell function
  • Plant Cell Anacharis (Elodea) leaf cells
    (1000x). 
  • What do you think is the function of these
    cells? 
  • How is the function dependent on the structure?

14
How does cell structure reflect cell function
  • Potato cells with stained leucoplasts (100x). 
  • The leucoplasts (starch storage units) have been
    stained with gram iodine (stains for starch)

15
What limits cell size?
  • Surface area-to-volume ratio needs to be greater
    for an exchange of materials

Microvilli some cells increase surface area by
micro-extensions called microvilli
http//distance.stcc.edu/AandP/AP/imagesAP2/digest
ion/microvilli.jpg
16
What is a plasma membrane made of? (how is a
cell membrane like a house?)
  • Phospholipids a. polar heads (hydrophilic or
    water soluble) b. nonpolar tails (hydrophobic
    or not water soluble)
  • Cholesterol gives strength to the cell
    membrane
  • Proteins transport, communication

17
What is the fluid-mosaic model of the cell
membrane?
  • How is it fluid? (flows, pliable) phospholipid
    bilayer
  • How is it a mosaic? proteins partially or wholly
    embedded

18
What are channel proteins? Space where a
substance moves across the membrane
  • What are carrier proteins?
  • Combine with a substance and
  • help it move across the membrane

http//www.aber.ac.uk/gwydd-cym/graffeg/biolgell/c
ludiant/sianel.gif
19
What are receptors? Specific shape that allows a
molecule to bind to it, ex) hormone
  • What are glycoproteins? For cell to cell
    identification

http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
5_11.jpg
20
How are membranes selectively permeable? Allows
some molecules to pass through and not others
  • What is passive transport?
  • Doesn't need energy to happen, goes with
    concentration gradient
  • What is diffusion? Movement of molecules from
    high to low concentration

http//www.biology.arizona.edu/cell_bio/problem_se
ts/membranes/graphics/CHANNEL.GIF
21
What is osmosis? Diffusion of water into and
out of cells
  • What is a solute? usually a solid
  • What is a solvent? usually a liquid
  • Define tonicity based on concentrations of
    solutes

22
  • What are isotonic solutions?
  • Same concentration of solutes on either side of
    the membrane

http//www.cat.cc.md.us/courses/bio141/lecguide/un
it4/metabolism/growth/images/isotonicanim.gif
23
What are hypotonic solutions?
  • Low solutes in solution, water enters the cell,
    hemolysis

http//images.google.com/imgres?imgurlhttp//www.
cat.cc.md.us/courses/bio141/lecguide/unit4/metabol
ism/growth/images/hypotonicanim.gifimgrefurlhttp
//www.cat.cc.md.us/courses/bio141/lecguide/unit4/
metabolism/growth/hypotonicanim.htmlh290w362s
z357tbnidlOPoZ-_M4ysJtbnh93tbnw117hlens
tart2prev/images3Fq3Dosmosis2Banimation26sv
num3D1026hl3Den26lr3D
24
What are hypertonic solutions?
  • High solutes in solution, causes water to leave
    the cell (water follows salt), crenation

http//www.cat.cc.md.us/courses/bio141/lecguide/un
it4/metabolism/growth/images/hypertonicanim.gif
25
(No Transcript)
26
What is turgor pressure? Plant cells swell in
response to a hypotonic solution
Put some wilted celery in a glass of cool water.
If it has not wilted too much, it will become
stiff again. This is because of turgor pressure
when the plant cell vacuoles become filled with
water, push against the cell walls and become
firm.
27
What is facilitated transport? Carrier proteins
assist movement of specific molecules
28
What is active transport? Requires ATP to move
molecules against their concentration gradient
  • What is the Na-K pump?
  • Concentrates more Na outside, K inside cell
    membranes

http//www.biologie.uni-hamburg.de/b-online/librar
y/biology107/bi107vc/fa99/terry/images/ATPpumA.gif
29
What is Exocytosis or Endocytosis? Move
materials outside or inside the cell
http//www.stanford.edu/group/Urchin/GIFS/exocyt.g
if
30
What is Phagocytosis? Cell eating, white blood
cells
http//faculty.uca.edu/johnc/leukocyto.gif
31
What is Pinocytosis? Cell drinking, root
cells get water
http//images.google.com/imgres?imgurlhttp//www.
cat.cc.md.us/gkaiser/biotutorials/eustruct/images
/pinocyt.gifimgrefurlhttp//www.cat.cc.md.us/gk
aiser/biotutorials/eustruct/pinocyt.htmlh362w3
63sz55tbnid0qGkaPabQ3MJtbnh116tbnw117hl
enstart1prev/images3Fq3Dpinocytosis2Banimat
ion26svnum3D1026hl3Den26lr3D26sa3DG
32
What is receptor-mediated endocytosis? Coated
proteins attract specific molecules to the cell
surface
http//srs.dl.ac.uk/VUV/home-page/hot-topics/graph
ics/uffig1.gif
33
Construction of the Cell Membrane
  • This is an interactive activity
  • Construction of the Cell Membrane
  • In this activity you will learn about the cell
    membrane structure by assembling it. Interactive
    exercise from Wisc-Online.

http//www.wisc-online.com/lrnobj/ap1/AP1101/index
.html
34
How do internal structures carry out specific
functions?
  • What are the structures of the nucleus?
  • Nuclear membrane has nuclear pore spaces
  • Nucleolus forms RNA and ribosomes
  • Chromatin all of the DNA molecules

35
What do ribosomes do? Assemble proteins
36
What does endoplasmic reticulum (ER) do?
  • Makes and transports large molecules
  • Smooth ER enzymes make lipids, steroids
  • Rough ER with ribosomes (RNA) have ribosomes for
    making protein

37
What does the Golgi apparatus look like? Stacks
of sacules (like pancakes)
  • What is its function?
  • Stores and distributes products from ER
  • Processes, packages and secretes
  • Breaks off pieces as vesicles (small sac)

38
What are Vacuoles? Large membranous sacs for
transport and storage
  • What do lysosomes do?
  • Digestive enzymes in vesicles
  • What are Peroxisomes?
  • Vesicles with enzymes that destroy toxins

39
What are mitochondria? Site for aerobic
respiration, "burns food"
  • Produces ATP cell's powerhouse
  • Cristae inner membrane increases surface
    area for metabolism
  • Matrix inner fluid-filled space

40
What are chloroplasts? Organelles only found in
plant cells
  • Photosynthesis use solar energy to make
    carbohydrates
  • Thylakoids interconnected flattened sacs
  • Grana stacks of thylakoids (granny's
    pancakes)
  • Stroma syrupy fluid filled space (syrup)

41
What provides cells with structure for support
and movement?
  • Cytoskeleton? interconnected microtubules and
    microfilaments
  • Cilia small whips, move cell, or fluids across a
    surface
  • Flagella larger whip, moves cell like an oar on
    a boat

42
Centrioles in animal cells for spindle fibers
during mitosis, pull chromosomes apart
43
How do cells use and transform matter and energy?
  • What are metabolic pathways? When one chemical
    reaction leads to another ex) A B -gt C D
  • What are reactants? participate in a reaction,
    ex) A B -gt (enzyme)
  • What are products? result from a reaction, ex) C
    D

44
What is Anabolism?
  • Building up of larger molecules, takes energy
    (endergonic)

What is Catabolism?
Breaking down into smaller molecules, gives
up energy (exergonic)
45
What is ATP? A universal packet of energy used
in cells
  • ATP adenosine triphosphate (Adenine-ribose-P-P-
    P)
  • Exergonic the energy currency of the cell
  • ATP -gt ADP P energy
  • Endergonic
  • ADP P energy -gt ATP

46
What is cellular respiration? Chemical
reactions that produce ATP in cells
  • What is glycolysis? breaks down glucose (C6) -gt 2
    pyruvate (C3) 2 ATP
  • Where does it take place? in the cytoplasm, in
    all cells, no O2 needed
  • How does it get started? it needs 2 P from 2 ATP
    activate glucose

47
What is aerobic respiration? Respiration with
oxygen
  • Where does it take place? Inside the
    mitochondria yields 36-38 ATP
  • What does the Krebs cycle do? 1) pyruvate is
    broken down to O2 acetyl group (C2) -gt 2
    CO2 2 ATP 2) NAD and FAD H2 -gt NADH and
    FADH2 -gt electron transport system

48
What does the electron transport system do?
  • Coenzyme carriers move electrons to make 32-34 ATP

49
What is fermentation? Alternative pathway of
energy when no oxygen is present
  • Glycolysis first
  • Alcoholic fermentation
  • Glucose is broken down to pyruvate, then to
    Alcohol CO2 2 ATP
  • Used for brewing, baking

50
What is lactic acid fermentation?
  • Glucose -gt pyruvate gt lactate 2 ATP
  • Used in making yogurt,
  • sour cream, cheese,
  • sauerkraut
  • In O2 starved muscles,
  • oxygen debt
  • O2 lactic acid to
  • pyruvate

51
Need more help?
  • For extra learning practice see links on Bb under
    CH 3
  • Read your test clues each night before you go to
    bed to help remember them
  • For extra credit fill out review sheet (1 pt) and
    write 15 multiple choice questions and answer
    them (1 pt)
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