Cell And Molec Test 3 Flashcards
(201 cards)
1
Q
What are the fibers of the cytoskeleton made out of? (3)
A
- microfilaments
- intermediate filaments
-microtubule
2
Q
What are the differences between micro filaments, intermediate filaments, and microtubules?
A
- microfilaments are the smallest, most simple and made of actin ~7nm
- intermediate has 9 types and is a complete structure ~10nm
-microtubules are the largest, they are a hollow tube made out of tubulin(?) ~25nm
3
Q
Do prokaryotes have a cytoskeleton? Do eukaryotes?
A
Only eukaryotes have a cytoskeleton, prokaryotes do not
4
Q
What are the 4 techniques for visualizing the cytoskeleton?
A
- fluorescence microscopy on fixed specimens
- live cell fluorescence microscopy
- computer-enhanced digital video microscopy
- electron microscopy
5
Q
Describe how Fluorescence microscopy on fixed specimens works
A
Fluorescence compounds directly bind to the cytoskeletal proteins, or antibodies are used to indirectly label cytoskeleton proteins in chemically preserved cells, causing them to flow in the fluorescence microscope
6
Q
Describe how live cell fluorescence microscopy works
A
Fluorescence versions of cytoskeletal proteins are made and introduced into living cells. Fluorescence microscopy and video of digital cameras are used to cure the proteins as they function in cells
7
Q
Describe how Computer enhanced digital video microscopy works
A
High resolution images from a video or digital camera attached to a microscope are computer processed to increase contrast and remove background features that obscure the image
8
Q
Describe electron microscopy
A
Electron microscopy can resolve individual filaments prepared by thin section, quick freeze dry etch, or direct mount techniques
9
Q
What is the largest of the cytoskeletal components of a cell
A
Microtubules
10
Q
What are the functions of microtubules?
A
- move chromosomes (main function)
- flagella movement
- “highways” for vesicles
11
Q
What 2 types of microtubules are responsible for the many functions in the cell?
A
-cytoplasmic microtubules
-axonemal microtubules
12
Q
What are the functions of cytoplasmic microtubules
A
-maintaining axons (axons are the long structures in nerve cells)
-formation of mitotic and meiotic spindles
-maintaining or altering cell shape
-placement and movement of vesicles
13
Q
What are axonemal microtubules?
A
they include the organized and stable microtubules found in structures such as : cilia, flagella, and basal bodies (cilia and flagella attach to)
14
Q
What is the axoneme?
A
A highly ordered bundle of microtubules
15
Q
Describe what is shown in the graph (in my notes) (LAG PHASE ELONGATION PHASE AND PLATEU PHASE
A
The first part of the graph (low/start) is the lag phase which is the period of nucleation
Then, during the elongation phase, (middle part) microtubules grow rapidly causing the concentration of tubulin subunits in the solution to decline when this concentration is low enough to limit further assembly, the plateau phase (high point flat at end) is reached during which subunits are added and removed from microtubules are equal rates
16
Q
What is critical concentration?
A
Concentration at which the rate of assembly of cytoskeletal protein subunits into a polymer is exactly balanced with the rate of disassembly
17
Q
What is the goal of the The microtubule organizing center (MTOC) (idk how to ask this question)
A
It anchors the negative end of the microtubule so it’s bound to the MTOC so it can’t shrink or grow. It can only shrink/grow at the positive end
18
Q
What happens to the microtubule when there is a high tubulin concentration
A
The microtubule grows, GTP-tubulin subunits are added
19
Q
What happens to the microtubule when the tubulin concentration is low?
A
The microtubule shrinks, GTP are hydrolyzed
20
Q
At what end do microtubules grow/shrink
A
They grow and shrink at the positive end, they anchor at the negative
21
Q
Which end of the microtubule is more dynamic? Why?
A
Positive end because that is where GTP is added and taken away (depending on the tubulin concentration) aka where it grows and shrinks
22
Q
What happens in the MTOC to the microtubules when tubulin concentration is high?
A
GTP-tubulin subunits are added
23
Q
What happens in the MTOC to the microtubules when there is low concentration of tubulin?
A
Catastrophe. GTP are hydrolyzed (therefore depleting the GTP cap)
24
Q
Microtubules are regulated by microtubule binding proteins. Why might they use ATP?
A
-drive vesicle/organelle transport
-generate sliding forces between microtubules
25
What are the functions of microtubule-binding proteins?
-drive vesicle or organelle transport (using atp)
-generate sliding forces between microtubules (using atp)
-regulate microtubule structure
26
Cells regulate _______ with great precision
Microtubules
27
What are microtubule-stabilizing/building proteins? (MAPS)
microtubule-associated proteins that bind at regular intervals along a microtubule wall. this allows for interaction with other cellular structures and filaments
28
What are the 2 microtubule stabilizing/bundling proteins (MAPs)?
- A MAP called Tau
- MAP2
29
What is the function of A MAP (Tau)?
They cause microtubules to form right bundles in axons
30
What is the function of MAP2?
they promote the formation of looser bundles in dendrites
31
What are dendrites?
short branched extensions of nerve cells (neurons) that receive signals from other neurons
32
Describe what the 2 regions of MAPs such as Tau and MAP2 each do
One region binds to the microtubule wall, and the other extends at right angles to allow for interaction with other proteins
33
What controls the spacing of the microtubules in a bundle?
The length of the extended “arm” of the MAP
34
What are +-TIP proteins?
- (+- end tubulin interacting proteins) are stabilizing proteins that “capture” and protect the growing positive end
-they decrease the likelihood that microtubules will undergo catastrophic subunit loss
35
What are 3 microtubule destabilizing/severing proteins?
- Stathmin/Op18
-Catastrophins
-proteins such as Katanins
36
How does Stathmin (or OP18) destabilize/sever microtubules?
-it binds to tubulin heterodimers and prevents their polymerization
37
How do catastrophins destabilize/sever microtubules?
at the end, they act on the microtubules and promote the peeling of du units from the ends
38
How do katanins (proteins) destabilize/sever microtubules
They sever the microtubules
39
What is “The Mesh” ?
-a network of microtubule connectors that stabilize individual kinetochore fibers of the mitotic spindle where the chromosome attaches
- yellow “lines” in the given photo
40
Each mesh structure holds 2 microtubules together, why?
Because the clathrin is a part of the mesh structure (in its turmeric state)
41
What is the smallest of the cytoskeletal filaments?
Microfilaments
42
Microfilaments have many roles, what do they include? What is the best known role they carry out?
- BEST KNOWN : their role in muscle contraction
also known for :
- cell migration
- ameoboid movement
- cytoplasmic streaming
- development and maintenance of cell shape (they push out the edges of the cell)
- structural core of microvilli
43
What is actin?
- a very abundant protein in the cell, it is a building block for all microfilaments
44
Once actin is synthesized, it is folded into a globular shaped molecule. What does this allow it to do?
It allows the actin to bind to ATP or ADP
45
Since microfilaments do not anchor themselves at one end, where do they shrink/grow
There is general shrinkage at the negative end and general growth at the positive end
46
When the myosin fragment S1 binds to the actin in microfilaments, a “pattern” is created - describe why this is
The myosin segment binds to the actin and creates an “arrow” pattern, where the arrow will point to the negative end creating the “pointed end” and the other end is referred to as the “barbed end”
47
Which is not dynamic: microtubules or microfilaments
Microtubules are more dynamic
48
I’m terms of length, which is more stable: microtubules or microfilaments?
Microfilaments are more stable in terms of length
49
Explain “tredmilling” in terms of microfilaments.
-since they gain G-actin monomers at the positive end while simultaneously they lose monomers at the negative end, the net change in length is zero.
-the actin monomers start at plus end and are displaced progressively more towards the negative end until depolymerization causing it to detach
50
When is the ONLY time “tredmilling” in microfilaments occurs?
In a test tube/in vitro
51
What are 3 specific drugs that affect polymerization of microfilaments?
- Cytochalasins
- Latrunculin A
- Phalloidin
52
How do Cytochalasins affect the polymerization of microfilaments?
- the prevent the addition of new monomers to existing microfilaments
- cytochalasins are fungal metabolites
53
How does Latrunculin A affect the polymerization of microfilaments?
- hides actin monomers and prevents their addition to microfilaments
- a toxin
54
How do Phallodin affect the polymerization of microfilaments?
- stabilizes the microfilaments and prevents their depolymerization
- can alter and even kill the cell
55
Cells can precisely control where actin assembles and the structure of the resulting network, how?
- they use a variety of actin-binding proteins in order to control the actin
- control occurs at the nucleation, elongation and severing of microfilaments
56
What are the most stable, and least soluble cytoskeletal components?
- intermediate filaments are both the most stable and least soluble
57
What is an example of an intermediate filament (very abundant)
- keratin, an important component of structures that grow from skin in animals; giving structure to the skin
58
How many different classes of intermediate filament proteins are there?
- 6
59
Which of the 6 classes of intermediate filament proteins is the most stable?
- class 5 (V)
60
Class I intermediate filaments are _____
- acidic keratins
61
Class II of intermediate filament proteins ___
- are basic or neutral keratins
62
What 2 classes make up tonofilaments? Where are the tonofilaments found?
-protien classes I and II
- found in epithelial surfaces covering the body and lining it’s cavities
63
Class III of intermediate filament proteins include ___
- vimentin (connective tissue), desmin (muscle cells) and glial fibrillary (GFA)
64
Class 5 (V) includes ____
- nuclear Kamins A, B, and C, that form a network along the inner surface of the nuclear membrane
65
Class 6 (VI) of intermediate filament proteins ____
- neurofilaments in the nerve cells of embryos are made of nestin
66
What is intermediate filament testing?
-animal cells can be distinguished based off of what types of intermediate filaments they contain
67
What are nucleotide triphosphates (NTP)?
- (rna) an umbrella term for : ATP, GTP, UTP, and CTP
68
What are deoxynucleotide triphosphates?
- (dna) dATP, dGTP, dCTP, dTTP
69
What is an allosteric site?
- a binding site distinctively different from the active site, that allows molecules to either activate or inhibit enzyme activity
70
What is a holoenzyme?
A complete enzyme including a cofactor, the enzyme, and once the substrate binds it is functional
71
Explain how the intermediate filament is assembled in vitro
2 intermediate filament proteins go through coiling, creating a coiled-coil dimer of 2 intertwined polypeptides.
Then, the coiled-coils line up (lateral alignment) creating a tetrameric protofilament of 2 aligned coiled-coil dimers.
They are then assembled in a staggered pattern (like bricks) into a long rope-like filament. The final structure consists of 8 protofilaments (16 coiled dimers) in staggered overlaps.
72
Which of the following is both flexible and can withstand tensile forces : microtubules, microfilaments, or intermediate filaments
- intermediate filaments
73
How do the microtubules and microfilaments work to support the cytoskeleton?
The microtubules resist bending when a cell is compressed while the microfilaments serve as contractile elements that generate tension
74
The nuclear lamina (on the inner surface of the nuclear envelope) disassembles when? When do they reassemble?
They disassemble at the onset of mitosis, and then reassemble afterward
75
Are intermediate filaments considered a static structure?
No. They are not static, they are dynamically transported and remodeled
76
What are Plakins?
- linker Proteins
77
What role does Plakins have in the cytoskeletal structure?
- the Plakins proteins connect the intermediate filaments, microfilaments, and microtubules
78
What is an example of a Plakin (name of it)
-plectin
79
Where is plectin found in the cytoskeleton?
At sites where intermediate filaments connect to microfilaments and microtubules
80
What are the 2 microfilament associated (actin binding) proteins? (Motor molecules)
- myosin I - monomer
- myosin II - filament (specialized)
81
What are the 3 microtubules associated proteins? (Motor molecules)
- cytoplasmic dynein
- axonemal dynein (specific to only flagella and cilia)
- kinesin
82
What is the function of myosin I and II ?
Myosin I helps with motion along the actin filaments
Myosin II I’d the thick filament of muscle cells
83
What is the function of cytoplasmic dynein? (MT associated motor molecule)
Responsible for movement towards the minus end of the microtubule (towards the MTOC)
84
What is the function of axonemal dynein?
Activation of sliding in Flagellar microtubule
85
What is the function of kinesin (MT associated motor protien)
Responsible for motion towards the positive end of the microtubule (AWAY from the MTOC)
86
What uses the motor proteins (such as kinesin and cytoplasmic dynein) for movement?
Vesicles
87
What is the structure of myosin I?
1 heavily coiled chain making up the “tail” which is attached to the “head” which is made up of an ATP binding site and an Actin binding site
-OOC -> heavy chain -> actin binding site -> ATP binding site -> NH3+
88
What is the structure of myosin II?
2 heavily coiled chains about each other (tail) connected to 2 “heads” therefore having 2 ATP binding sites and 2 Actin binding sites
89
Where is myosin II usually used? (What body cells)
- muscle cells - used for contraction
90
What allows the Dynein/Kinesin to move along the microtubule? (What is the energy source)
- ATP hydrolysis
91
What are the 3 proteins that make up thin filaments?
- F-actin
- tropomyosin
- troponin
92
Which 2 proteins are very sensitive to calcium?
- tropomyosin and troponin
93
What 3 component make up troponin ?
- 3 poly peptides: TnT, TnC, TnI
94
What 2 proteins constitute a calcium sensitive “switch”? When does that switch activate?
- when 1 troponin complex associated with a tropomyosin
- activates contraction in striated muscle
95
What does the regulation of muscle contraction depend on?
- calcium
96
Most skeletal muscle spends time in what state : in contraction or relaxed
- more time in a relaxed state
97
T/F : muscle contraction and relaxation must be coordinated
True
98
Myosin binding sites are normally blocked by what? If this is removed, what forms?
- normally blocked by tropomyosin
- will form cross-bridges
99
What do tropomyosin and troponin regulate ?
- availability of myosin binding sites on actin filaments in a calcium dependent manner
100
When calcium concentration is low, how is interaction between the actin filament and myosin prevented?
- tropomyosin blocks the myosin binding sites on the actin filament
101
When calcium concentration is high, what does it bind to? What does this allow to for?
- binds to TnC
- slows for the myosin to bind because of the tropomyosin shift
102
Calcium levels are controlled by what?
- nerve impulses from motor neurons
103
Muscle contraction is regulated by what?
- calcium ions in the sacroplasm
104
What is the sarcoplasm ?
- cytosol of muscle cell
105
What is the neuromuscular junction?
- the site where a nerve contracts a muscle cell conveying a signal to contract in the form of an action potential
106
Where do axon terminals make contact with the muscle cells?
At the neuromuscular junction
107
Where is acetylcholine released from? What is this a response to?
- the axon terminals store and then release the acetylcholine in response to an action potential
108
How do amoebas move ?
By ameboid motion - attach the pseudo foot in front of them and move themselves towards it
109
How does actin aid crawling cells
The actin filament cytoskeleton pushes and contracts, slowly moving the cell
110
Give an example of membrane protrusion due to actin polymerization
The formation of an acrosomal process in Sea cucumber sperm (thyone)
111
How do cilia and flagella move?
The dynein motor proteins generate the motive force by pushing against the microtubules, to bend the flagellum and cause it to move in a whip like motion through the surrounding fluid
- referred to as flagellar or ciliary beat
112
The MTOC (microtubule organizing center) has other equivalent names (3)
- centriole
- centrosome
- basal body
113
What is the structure of a Basal body
“ 9 + 0 structure “
- 9 doublets composed of an A microtubule and a B microtubule
114
What is the structure of an axoneme?
“ 9 + 1 structure “ - 9 doublets around and one in the middle made of 2 microtubules (A and B)
- connected with radial spokes
115
Where are primary cilia used?
- sensory structures
116
What is the structure of primary cilia? (9 +)
- 9+0 ( no central doublet )
117
What can cause deafness and left-right asymmetry reversals ?
- defects in primary cilia
118
What does a cofactor do?
Attaches to the allosteric site of an enzyme in order to change the shape of the binding site of the substrate - once bound, you have function
119
What is the difference between a competitive inhibitor and a non competitive inhibitor
- A competitive inhibitor mimics the substrate and blocks it from binding
- a non competitive inhibitor binds at another site changing the shape of the binding site so the substrate does not fit
120
What is the optimal pH for enzymes
5.0
121
Increasing concentration of substrate molecules caused the rate of reaction to do what?
Rate of reaction will increase, until the active sites on all the enzymes molecules are filled (maximum reaction rate)
122
What are some causes of denatured proteins
- pH changes
- temperature changes
- concentration changes
123
What bonds are broken when a protein is denatured
- non covalent bonds (such as hydrogen bonds)
- these bonds hold the protein together in its 3D shape
124
Describe what happens in the ATP cycle
Energy from an exergonic reaction goes in and due to dehydration synthesis ATP is created. Then, energy is expelled during hydrolysis and goes to the endergonic reactions, splitting the ATP into ADP + P
125
What is chemiosmosis?
- the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient
- the formation of ATP by the movement of H+ will diffuse from a region of high proton concentration to low concentration during cellular respiration/photosynthesis
126
What is phosphorylation - give an example (ATP)
- the attachment of a phosphate group to a molecule or ion
- ADP + P —> ATP
- de-phosphorylation : ATP —> ADP + P
127
What is the cellular respiration equation (must know)
C6H12O6 + 6O2 —> 6CO2 + 6H2O + ATP
Glucose + oxygen gas —> carbon dioxide + water + energy
128
Using the equation for cellular respiration, label what is the reduction and which is the oxidation portion of the equation
- reduction : 6O2 -> 6H2O
- oxidation : C6H12O6 -> 6CO2
129
Give a quick overview of cellular respiration (steps, processes)
Glycolysis (glucose to pyruvic acid) —> Krebs cycle (produces NADH and FADH2) —> electron transport chain
- ATP is produced at each step
130
The inside of the mitochondria looks like wwwww (folded structure). Why is this? What is the benefit?
- the folds create more surface area, allowing for more ATP (energy) to be created
131
What structures do mitochondria have that leads us to believe they used to be their own bacteria?
- they have their own DNA, tRNA, ribosomes, and mRNA
132
Give an overview of the glycolysis process.
What goes in, what comes out, what is created (“ break down sugar”)
Glucose (6 carbon sugar) is split, 2 pyruvic acids are created
2 ADP + 2 P —> ATP
2 NAD+ —> 2 NADH + 2H+
133
How many total ATP is produced from glycolysis? How many net ATP is produced from glycolysis?
- total : 4
- net : 2 (2 are imputed to
134
When NAD+ gains a hydrogen, it becomes NADH. Is this a reduction or an oxidation reaction?
- reduction
135
Write the overall reaction of glycolysis
Glucose + 2 NAD+ + 2ADP + 2P —> 2 pyruvate + 2 NADH + 2 ATP
THIS IS DONE TWICE
136
In the conversion of pyruvic acid to acetyl coenzyme a, pyruvic acid is oxidized or reduced?
Oxidized
137
T/F : glycolysis requires O2
- false. Glycolysis occurs whether o2 is present or not
138
Where in the cell does glycolysis occur?
- cytoplasm
139
What are the folds of the mitochondria called
- Cristae
140
What is the prep story step in glycolysis ( Explain the process of pyruvic acid becoming acetyl CoA )
- pyruvate oxidation
- 1 carbon is removed from pyruvate making it acetyl coA (a 2-carbon chain)
- during this process, NAD+ becomes NADH
141
Krebs cycle is also known as what
Citric acid cycle
142
What is the Krebs cycle? What goes in what comes out
In - Acetyl CoA
Out - 3 NADH (x2), 1 ATP (x2), 1FADH2 (x2)
—> total: 6NADH 2ATP 2FADH2
143
How many NADH come from the preparatory stage? (Before Krebs cycle, after glycolysis)
- 2
144
After the Krebs cycle, how many net ATP, NADH, and FADH2 have been produced so far?
- 4 ATP
- 10 NADH
- 2 FADH2
145
What gets imputed into the ETC? (Electron transport chain)
- NADH and FADH2
146
How many ATP can be made in the ETC from both the NADH and the FADH2 (each)
- each NADH can produce 3 ATP
- each FADH2 can produce 2 ATP
~ going into the ETC, 10NADH are imputed giving a total of 30 ATP and 2 FADH2 are imputed giving 4 ATP
147
How many NET total ATP are produced during cellular respiration. How many TOTAL?
- NET : 36-38
- TOTAL : 38-40
148
Is the ETC is what kind of transport
Indirect active transport
149
What does NADH reductase do? (in the ETC)
- strips the NADH of its hydrogen
150
(ETC) When NADH loses its hydrogen, what/where is it transfered to ?
- hydroxyquinone
151
(ETC) once the hydroxyquinone posesses a hydrogen, where does it go
Gets bound to cytochrome C
152
Where does the ETC take place
In the mitochondrial membrane
153
What is the final electron acceptor?
Oxygen
154
(Cellular respiration) After glycolysis, of no oxygen is present what happens? (2 options)
- alcoholic fermentation or lactic acid fermentation
155
Is alcoholic fermentation aerobic or anaerobic respiration?
- anaerobic
156
What is the difference between heterolactic and homolactic ?
- homolactic : only lactic acid can be produced
- heterolactic : can produce many types of acid
157
What product is made from the alcoholic fermentation cycle?
- 2 ethanol which can be used to make other products
- 2 NAD+
- 2 CO2
158
What is the output of the lactic acid cycle?
- 2 ATP
- 2 NAD+
- 2 lactic acid molecules
159
Is the hydrolysis of ATP to ADP an exergonic or endergonic rxn?
- exergonic
160
Is the synthesis of ADP to ATP an exergonic or endergonic reaction?
- endergonic
161
Draw a molecule of ATP. What is the difference between this and ADP?
…
162
What are 4 NTPs ? (Nucleotide triphosphates)
- ATP
-GTP
-UTP
-CTP
163
What are the 4 deoxyribose triphosphates?
-dATP
-dGTP
-dCTP
-dTTP
164
Which dNTP or NTP is used the most ?
ATP
165
Draw an NAD+ - how does it become NADH
…
166
What is the function of NAD+
- it is a hydrogen carrier
167
What is the definition of photosynthesis
The process by which autotrophic organisms use light energy to make sugar and oxygen gas from carbon dioxide and water
168
In what organisms does photosynthesis occur
Plants, algae, and some prokaryotes
169
Is photosynthesis an endergonic or exergonic reaction
Endergonic - it stores energy
170
What is energy stored as (when using photosynthesis)
- carbohydrates
171
What is the formula for photosynthesis
6CO2 + 6H2O —> C6H12O6 + O2
^ light energy added
172
What is the definition of carbon fixation
The process by which inorganic carbon from the atmosphere is assimilated into living organisms and converted to organic compounds
173
When does carbon fixation occur in photosynthesis (before which process)
Before the Calvin cycle
174
In which organelle does photosynthesis occur
Chloroplast
175
What structure in the chloroplast does photosynthesis occur
Thylakoids
176
What are stoma?
The holes on plants that the plant can get CO2 from
177
What are granum
A stack of thylakoids
178
In the formula for photosynthesis, follow where each molecule “goes” (6CO2 - the carbon goes to which product, the oxygen goes to which product)
- 6 CO2 : Carbons go to glucose, oxygen does to water
- 12 H2O : Hydrogens go to glucose and water, oxygen is converted to oxygen gas (O2)
179
In photosynthesis, which part of the reaction is being reduced and which part is being oxidized
The CO2 is reduced to glucose
The water is oxidized into O2 gas
180
What is the function of NADP+
- it is a hydrogen carrier
- similar to NAD+
181
What are the 2 processes of photosynthesis?
- light reaction
- dark reaction (Calvin cycle)
182
Why is the Calvin cycle also called the dark reaction?
- because it happens in the absence of light
183
Why are plants green
Light passed through the chloroplasts, the green light is reflected back into our eyes and the rest of the colors’ lights are absorbed into the chloroplast
184
What wave lengths does photosynthesis mostly occur
- 400-500 and 600-700 ( purples and blues to oranges and reds )
185
Which photosystem splits the water? Which photosystem produces NADPH
- photosystem II splits water
- photosystem I produces NADPH
186
Draw NADPH
…
187
Where does cyclic photophosphoylation take place? (PS I PSII both or neither). At what wavelength
Only photosystem I, 700nm
188
What is the end product of cyclic photophosphorylation
ATP only
189
Where does non-cyclic photophosphoylation take place? (PS I PSII both or neither). At what wavelength
Both photosystem II (680nm) and photosystem I (700nm)
190
What does non cyclic photophosphorylation produce
NADP, ATP, and O2
191
Where does the dark reaction (or light independent, or Calvin cycle) take place?
In the Stroma of the chloroplast
192
What enzyme does the light independent reaction require?
- RUBISCO (ribulose biphosphate carboxylase)
193
In the Calvin cycle (also called carbon rxn pathway, light independent, and dark cycle), what is the cleavage of P (from ATP) used for
That energy is used to fix and reduce CO2 to form a carbohydrate
194
What is the most abundant biological molecule on earth
RuBP
195
Give a summary of the Calvin cycle
- 3 5-carbon ribulose-1,5-bisP (total of 15 carbons) are carboxylated (meaning 3 carbons are added), cleaved, phosphorylated, reduced, and dephosphorylated
- this yields :
1 3-C glyceraldehyde-3-P exits as a product
5 3-C glyceraldehyde-3-P (15C) are recycled back into 3 5-C RuBP
196
How is the rate of photosynthesis defined?
- the rate of oxygen production per unit mass of green plant tissues or per unit weight of total chlorophyll
197
What are the main factors that can affect photosynthesis
- light intensity
- wavelength
- CO2 concentration
- temperature
- water supply
- chlorophyll concentration
- pollution
198
What is the main function of microtubules
- cell movement and intrazellularem Transport
- cell shape
199
What is the main function of microfilaments
- help generate the forces used in cellular contraction/basic cell movements
200
What is the main function of intermediate filaments?
- they are mechanical stress absorbers and an integrating device for the entire cytoskeleton
201
Draw a sacromere
…
