Download 1 Chapter 3-b2 Cell Structure and Function Applying the concepts

1
Chapter 3-b2
Cell Structure and Function
I.
Applying the concepts
A.
What is the difference between Prokaryotic and eukaryotic cells?
1.
a.
No nucleus
b.
No membrane bound organelles
c.
d.
Bacteria
2.
Eukaryotic (true nucleus)
a.
b.
Membrane bound organelles (why is this beneficial?)
c.
Small to large in size
d.
B.
Eg. RBC’s-red blood cells-erythrocytes
1.
No nucleus or organelles
-Nucleus pinched off & organelles are destroyed
2.
Allows greater flexibility to get to every cell with much needed oxygen
3.
a.
Hemoglobin holds oxygen
b.
280 million hb in 1 RBC!
~illustrates no typical animal cell
II.
A.
The cell marks the boundary between living and nonliving
1.
Smallest unit capable of performing functions necessary for life.
2.
Organisms
a.
Unicellular
B.
Cells can be classified as either prokaryotic or eukaryotic cells
1.
Eukaryotic cells
a.
b.
All have the SAME basic structure
2.
Prokaryotic cells
a.
More primitive
b.
Hypothesize that eukaryotic cells came from prokaryotic cells
3.
a.
All organisms made up of cells
b.
All cells come from pre-existing cells
Cell size
1.
Some can be seen with unaided eye
2.
a.
Micrometer (.001 of millimeter)
b.
Nanometer (.001 of micrometer)
3.
Small size is a great advantage for multicellular organisms
a.
Surface area important to efficiency of the movement of
gas/food/waste.
b.
p. 47 fig. 3.2
c. actively metabolizing cells are small
C.
2
III. Prokaryotic cells
A.
Domains
1.
2.
Bacteria
B.
Plasma membrane and cytoplasm
1.
a.
Phospholipid layer
b.
c.
Barrier to environment or other cells
2.Cytoplasm
a.
Semifluid medium
b.
Contains
-water, salts and dissolved organic molecules
C.
1. Structurally simple
2. More metabolically diverse than eukaryotes
3.
a. cell wall outside of plasma membrane/protects
b.Capsule-some outside cell wall
c.
Slime layerd.
Flagella-some have for movement (like propellers)
e.
Fimbriae-some, short appendages that allow attachment to
appropriate surface
4.Capsule & fimbriae found in pathogenic bacteria
5.Chromosome
a.
b. nucleoid (area)
c. Plasmids
-additional rings of DNA
6.
a. to manufacture protein
b. some antibiotics target bacterial ribosomes
7. Thylakoids
a.
b. Cyanobacteria
D. Man exploites bacteria
1. Ribosomes make proteins quickly & easily
2.
a. bacteria makes insulin
b. bacteria makes blue dye for jeans
IV. Eukaryotic cells p. 49 Table 3.2
1.
2.
All have a nucleus
All have membrane-bound organelles
1.
2.
Permeable yet protective
Primary and/or secondary cell walls
a.
Cellulose
-strength
b. Lignin
-secondary formed inside primary cell wall
-added strength
A.
3
-ex. Fungus (cellulose & chitin)exoskeleton of
insects
B.
1.
2.
3.
Defined-subcellular structure with a specific function
Cell takes in substances & organelles process them
-centrioles for cell division
4. Plant cells only pg. 51
-Chloroplasts for photosynthesis
D.
1. Function
-stores genetic material for control of the cell
2. Structure
a.
b.same DNA in every cell/ only certain parts of DNA is turned on in a cell
c.
-genetic material not in dividing cell
d.Nucleoplasm-cytoplasm of nucleus with a different pH of cytoplasm
e.Nucleolus
-makes ribosomes
f. Nuclear envelope
-double membrane
g. Nuclear pores p. 52
-permits bidirectional transport
E.
1. Protein synthesis occurs here
2.
3. Polyribosomes
4. Ribosomes attached to ER
5. Tags put on protein to direct location of protein (in or out of cell?) like zipcodes
F. The Endomembrane System-organellewhich are connected wither directly or
by transport vesicles
1.
a.
Rough ER
-ribosomes attached for quick transport of proteins
-protein enters ER & folded for transport
CYSTIC FIBROSIS-protein to remove mucus in lungs not folded properly & cannot be transported to
do its job.
b.
-no protein synthesis
-makes phospholipids unique to each cell
Ex. Testosterone in tests/liver detoxifies, etc.
2.
The Golgi Apparatus (Post office of the cell)
a.
-3 to 20 stacks similar to pancakes
b. Function
-collects, stores & packages proteins & lipids made by the cell
-Animal cells (1 side face plasma membrane & 1 side
faces ER)vesicles are at the edge. Pg. 55
-
4
-forms lysosomes (garbage trucks/garbage disposal)
3.
a. contains hydrolytic digestive enzymes
b.
breaks down macromolecules
(pathogens) so other organelles can absorb.
c.
-breaks itself down
-eg. Webbing between fingers/toes in fetus
-eg. Tay Sachs (nerve disease) Cannot remove excess lipids &
death occurs by age 3
4.
a. larger than vesicle
b. Plants-Lg. vacuole to gives support to the cell
c.
d. removes substances
-eg. Contractile vacuoles get rid of water in aquatic organisms
G.
1. contains enzymes made in cytoplasmic ribosomes
2.makes H2O2 & then broken to H+ and O2
3.
4. Some make bile salts
5.
6. Plant perioxisomes
-oxidize fat in seed to helps germination
H. Energy-related organelles
1.
a. contain chlorophyll to capture solar energy & make it into
chemical energy (glucose)
b.
c. PLASTIDS (organelles)
-Amyoplasts in roots to store starch
-Chromoplasts in leaves (red/orange pigments)
d.STROMA-circular DNA (for controlling & making proteins)
e. THYLAKOIDS (flattened sacs in chloroplast)
-helps to capture sunlight & make carbohydrate-glucose
f. reproduce independent of cell
2.
a. cellular respiration
-breaks glucose for energy (ATP)
Glucose + oxygen-----H2O + CO2 + ATP
b.
c. involved in cell death & aging
d. reproduce independent of cell
e. MATRIX similar to stroma of chloroplasts
-ribosomes
f. CRISTAE
-increase surface area
5
-increases ATP production
g. Number varies with type of cell
h. only comes from EGG – not sperm during conception
I.
1. Function
a. maintains cell shape
b. allows cell to move if it needs to
c.
d. dynamic process
2. Structure
a. Actin filaments (old word was microfilaments)
-long
-flexible fibers
-occurs as a twisted mesh p. 59
-found under plasma membrane (allows for amoeboid movement)
-eg. Muscle p. 59
Myosin (head/tail) + ATP moves actin filament to
cause muscle to move
b.Intermediate filaments
-gives support to cell (varies with type of tissue)
-eg.
-eg. Support plasma membrane (skin/human hair)
c. Microtubules
-centrosome in animal cells controls microtubules
-spindle apparatus during mitosis/meiosis.
-eg. Increase in chameleon for movement of pigments quickly
d. Centrioles
-centrosome contains 2 centrioles for mitosis/meiosis
e. Cilia & Flagella p. 62
-movement whip-like or like an oar
-CILIA-tiny hairs
eg. Man respiratory tract
-FLAGELLA-long whiplike tail(s) eg. Sperm & protozoa
V. Origin & evolution of the eukaryotic cell
A.
1. suggest first cells are prokaryotes
2. belief that eukaryotic came from prokaryotic cells
B.
1. Mitochondria & chloroplasts similar to bacteria in size & structure
2.Membranes folded in on themselves & created membrane-bound organelles
3.
4.Mito/chloro have own ribosomes like bacteria
5.