01 Bioenergetics Flashcards
1
Q
Describe what is meant by the term glycolysis and what it is the initial component of?
A
“lysis” = breaking, of glucose.
Aerobic metabolism
2
Q
Describe the process and products of aerobic and anaerobic metabolism
A
Aerobic - pyruvate
Anaerobic - “fermentation” and produces lactate or ethanol
3
Q
What is the end product of glycolysis? (energy and molecule)
A
2 net ATP and pyruvate
4
Q
State what products are formed at each of the 10 steps in glycolysis
A
- Glucose
- Glucose-6-phosphate
- Fructose-6-phosphate
- Fructose-1,6-bisphosphate
- GAP (glyceraldehyde-3-phosphate) / DAP (dihydroxyacetone phospahte)
- 1,3-bisphosphoglycerate
- 3-phosphoglycerate
- 2-phosphoglycerate
- phosphoenolpyruvate
- Pyruvate
5
Q
What steps is ATP invested and produced in glycolysis?
A
ATP invested in 1-2 (glucose to glucose-6-phosphate) and in 3-4 (fructose-6-phosphate to fructose-1,6-bisphosphate)
ATP produced in 6-7 (1,3-bisphosphoglycerate to 3-phosphoglycerate) and 9-10 (phosphoenolpyruvate to pyruvate)
6
Q
Name the 5 properties of water
A
- powerful solvent
- polarity attracts positive and negative charges
- forms barriers with hydrophobic molecules (lipids —> membranes)
- allows/drives structure and shape of molecules, base pairing of DNA
- transports substrates
7
Q
How did life’s chemistry most likely begin?
A
- interactions on the surface of rocks and clays
- high temperatures driving reactions
8
Q
Explain the relevance of Miller and Urey’s findings
A
- recreating the environment in which earth was created
- amino acids and metabolites could from
- life likely started from an abundance of organic molecules and elements
9
Q
How are polymers formed?
A
dehydration
10
Q
What are the basic subunits of polymers called?
A
monomers
11
Q
Name the 4 types of polymers
A
lipids, polysaccharides, proteins and nucleic acids
12
Q
How does the presence of polymers tell us where life started?
A
polymers are the basic structural units of macromolecules, and life requires macromolecules
13
Q
What is the initial building block of a lipid called?
A
acetate
14
Q
What makes fatty acids amphipathic?
A
addition of phosphate
15
Q
Name the three functions of lipids
A
- energy storage
- structural molecules (membranes)
- steroid hormones
16
Q
Name the subunits of a fat/ triglyceride molecule and state the bond between them
A
- glycerol, 3 fatty acid chains
- ester linkage
17
Q
What is the difference between saturated and unsaturated fatty acids?
A
- saturated - all carbons are bonded to hydrogen in the FA chain, no kinks, pack closely together
- unsaturated - kinks, hard to rotate, cant pack close together
18
Q
What is the structure of a phospholipid and what makes this special in terms of beginning of life?
A
2 fatty acid chains, glycerol and a phosphate linked group - hydrophilic and hydrophobic regions - make micelle - first from of replication
19
Q
What is a different name for disaccharide?
A
oligosaccharide
20
Q
What is the name of the bond in polysaccharides?
A
glycosidic linkages
21
Q
What is the function of polysaccharides?
A
energy storage and structure
22
Q
Name the two main polysaccharides for energy storage
A
glycogen and starch
23
Q
Name the two main polysaccharides for structure
A
Chitin and cellulose
24
Q
State a structural difference between glycogen and starch and why this is of significance
A
- starch has fewer branches, glycogen has extensive branching.
- the branching in glycogen is due to the fact that humans move a lot more and need to pack in more glycogen for energy storage and fuel
25
Where is glycogen stored?
liver and muscle
26
State the bonding type in glycogen and starch and its significance
alpha 1-4 bond, flexible and can move
27
State the bonding in cellulose and chitin and its significance
beta 1-4 - cannot rotate
28
What are nucleic acids?
they form DNA and RNA
29
What is the structure of a polynucleotide?
phosphate group, pentose sugar and a nitrogenous base
30
What bond is in polynucleotides?
phosphodiester bond
31
What do nucleic acids and proteins have in common structurally
they are composed of variating monomers
32
What 2 structural units in nucleic acids can differ, explain the difference
- nitrogenous bases: can be purines or pyrimidines (Purines - larger AG and Pyrimidines - smaller CTU)
- phosphate sugar: deoxyribose or ribose sugar
33
Breakdown is a _______ process
catabolic
34
Build up is an _______ process
anabolic
35
Describe the breakdown of ATP and how it provides energy
ATP breaks down into ADP and Phosphate. This releases energy and can fuel other reactions
36
How does ADP turn into ATP?
through digestion and the breakdown of molecules, providing energy to turn ADP back to ATP. this is exergonic
37
What is the difference between and endergonic and exergonic reaction?
exergonic reactions release energy whilst endergonic reactions require energy input
38
State the 4 exit pathways of heat during food consumption
- digestion and absorption
- cellular respiration
- biosynthesis
- cellular work
39
State two ways in which energy is lost during food consumption
through feaces (undigested material such as cellulose) and through nitrogenous waste in urine
40
What macromolecule releases the most energy and which one the least ?
fats release the most, carbohydrates release the least
41
Which molecule is key to the synthesis of ATP and describe pathway?
- acetyl coa
- macromolecules broken down to micro nutrients, these make acetyl coa, acetyl coa feeds into citric acid cycle, the electron transport chain which generates ATP
42
Why is fat the most efficient molecule to release energy?
easier for enzymes to get to the C-H and C-OH bonds instead of C-C bonds.
43
Why is ATP the source of energy? (selected for)
most stable in water and water is essential to life
44
Why is ATP the source of energy? (selected for)
most stable in water and water is essential to life
45
What part of ATP carries the energy and explain how?
- phosphate
- phosphates joined together repel each other making the charges move to different sides (push away) - energy in the molecule, wants to break off
46
What makes ATP more powerful?
when the phosphates attract calcium or magnesium. it changes how the charges interact and gives the terminal phosphate more charge
46
Define Gibbs free energy
amount of energy that can be liberated from things - how much work we can do
47
What is the formula for Gibbs free energy?
Gibbs free energy = Δenthalpy - (temperature x Δentropy)
48
Why does a reaction with -ve gibbs free energy happen more spontaneously?
reaction is releasing energy, it is exergonic compared to a +ve gibbs value where energy must be supplied for the reaction to occur
49
How do ATP and gibbs free energy relate and give an example?
- ATP can drive unfavourable reactions
- glutamic acid + ammonia to form glutamine is an endergonic reaction.
- ATP phosphorylates glutamic acid **making the aa less stable**
- ammonia **displaces the phosphate group** forming glutamine
- this reaction is now exergonic
50
Describe the general energy flow through life
- photosynthesis
- organic molecules + oxygen feeds into mitochondria
- mitochondria generates ATP which powers cellular work
- carbon dioxide and water released - feeds back into photosynthesis.
51
How does digestion supply regeneration of ATP
it provides macronutrient fuel sources that supply substrates to regenerate ATP (eg. Deaminated amino acids, glucose and free fatty acids)
52
What are the three stages of catabolism that are used to generate ATP?
1. hydrolysis of complex molecules to their building blocks
2. conversion of building blocks to Acetyl CoA
3. Oxidation of acetyl CoA occurs by oxidative phosphorylation
53
What are the two laws of thermodynamics?
1. energy cannot be created or destroyed, only converted
2. The universe is becoming increasingly disordered
54
What is the formula for the first law of thermodynamics?
ΔH= q+ w (change in enthalpy is heat + work)
55
What is the significance of a -ΔG
the more negative, the more work that can be done. BUT it does not predict the rate at which reaction will occur!!
56
Why is oxidation important in metabolic pathways?
Oxidation reactions extract energy from bonds because leaving hydrogens take electrons (used in metabolic pathways)
57
What enzymes do redox reactions use?
de-hydrogen-ases
58
How many net ATP does glycolysis produce
two
59
What are the three stages of cellular respiration?
glycolysis, citric acid cycle, oxidative phosphorylation
60
what is KM?
Km value is equal to the substrate concentration at which half of the enzyme active sites are saturated with the substrate.
61
What is the relationship between KM and affinity?
A high KM = low affinity (it takes more substrate to get to Vmax)
62
At what stage is glucose trapped in the cell?
When glucose is converted to glucose6-phosphate. The addition of the phosphate makes glucose highly polar and polar molecules cannot cross the cell membrane, it is also no longer recognised by the GLUT transporters.
63
What is the commitment step in glycolysis?
- When fructose-6-phosphate is converted to fructose-1-6-bisphosphate. Fructose-1,6-bisphosphate can only undergo the reaction of glycolysis. (i.e. ready for catabolism)
- PFK enzyme
(The components of the pathway up to this point can have other metabolic directions.)
64
In what stages of glycolysis is ATP invested?
1. Glucose - glucose.6-phosphate
2. Glucose-6-phosphate Fructose-1,6-bisphosphate
65
At what step does a redox reaction occur is glycolysis?
Glyceraldehyde-3-phosphate to 1,3-bisphosphiglycerate.
The cofactor NADH is used and a P is added
66
What enzyme produces NADH + H+ in glycolysis?
GAPDH - Glyceraldehyde-3-phosphoate dehydrogenase
67
In whats steps in glycolysis is ATP generated?
1. 1,3-bisphosphoglycerate to 3-phosphoglycerate
2. Phosphoenolpyruvate to pyruvate
68
What are the products of glycolysis ?
2 ATP net and 2 NADH
69
What 3 enzymes are highly regulated in glycolysis?
Hexokinase/glucokinase
Phosphofructokinase
Pyruvate Kinase
70
How is PFK regulated?
- high ATP (why make more and waste glucose)
- AMP activates PFK (low ATP - make more)
- Citrate inhibits PFK
- Acidification inhibits PFK
71
What molecule is used in anaerobic glycolysis ? What are the drawbacks and benefits of anaerobic metabolism?
NAD - produces lactate
enzyme - lactate dehydrogenase (LDH)
15x less ATP, but 100x faster
72
What is the cori cycle?
the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate.
73
What is the main function of the CAC?
oxidise acetyl-CoA
74
What is the fate of pyruvate in the CAC?
Pyruvate is converted to Acetyl-CoA which is then further oxidised to CO2
75
What are the four oxidation or dehydrogenation reaction which transfer electrons to the electron accepting coenzymes NAD+ and FAD?
1. Isocitrate to alpha-ketoglutarate (NADH is formed)
2. alpha-ketoglutarate to succinyl co-A (NADH is formed)
3. Succinate to Fumarate (FADH2 is formed)
4. Malate to oxaloacetate (NADH is formed)
76
What are the steps of converting pyruvate to Acetyl CoA
1. a carboxyl group is removed from the pyruvate by pyruvate dehydrogenase, releasing carbon dioxide
2. NAD + is reduced to NADH
3. an acetyl group is transferred to Coenzyme A resulting in Acetyl CoA
77
Is the conversion of pyruvate to Acetyl CoA reversible? Explain.
No. very large –ΔG, and regulated
78
What are the three coenzymes of the CAC cycle?
Coenzyme A, NAD+ and FAD
79
What are the steps of the CAC and what are the enzymes involved?
1. acetyl CoA joins with oxaloacetate through the enzyme citrate synthase, releasing the CoA and forming citrate.
2. Citrate is converted to isocitrate by 1. the removal of water and 2. the additon of water (rearrangement enables OH oxidation) by the enzyme aconitase
3. Isocitrate is oxidised, released one CO2, forming α-ketoglutarate. NAD is reduced to NADH by the enzyme isocitrate dehydrogenase
4. α-ketoglutarate is oxidised, reducing NAD to NADH and releasing a molecule of carbon dioxide in the process. The remaining four-carbon molecule picks up Coenzyme A, forming the unstable compound succinyl CoA. The enzyme catalysing this step, α-ketoglutarate dehydrogenase.
5. CoA is replaced by a phosphate group (in succinyl CoA), and substrate level phosphorylation occurs either GTP or ATP is made. enzyme is succinyl CoA synthase
6. Succinate is oxidised by succinate dehydrogenase, forming fumarate. two hydrogen atoms—with their electrons—are transferred to FAD, producing FADH2. The enzyme that carries out this step is embedded in the inner membrane of the mitochondrion (complex II), so FADH2 can transfer its electrons directly into the electron transport chain.
7. enzyme fumerase adds water to fumarate, converting it into malate.
8. malate is oxidised by malate dehydrogenase forming oxaloacetate Another molecule of NAD is reduced to NADH in the process.
80
In the CAC during substrate level phosphorylation, where is GTP and ATP made?
GTP - liver
ATP - muscles
81
For two pyruvate molecules, what are the products of the CAC?
6CO2
8NADH
2FADH2
2GTP or ATP
82
What are the CAC intermediates used for? Give a few examples.
Biosynthesis of important molecules
Ex. Oxaloacetate - aa synthesis
Malate - glucose (glucogenesis)
Citrate - Fatty acids
83
What would happen if arsenic was added to the CAC?
α-ketoglutarate dehydrogenase and pyruvate dehydrogenase are both poisoned/inhibited = reduced conversion of pyruvate to acetyl coenzyme A (CoA), so that both the citric acid cycle activity and production of cellular ATP are decreased
84
How is the citric acid cycle regulated?
The citric acid cycle is controlled through the enzymes that break down the reactions that make the first two molecules of NADH.
depends on levels of ATP and NADH
85
What are the three regulatory enzymes of the CAC and how are they regulated?
1. citrate synthase - inhibited by high concentrations of ATP, acetyl-CoA, and NADH
2. isocitrate dehydrogenase - ATP and NADH inhibit, ADP activates
3. α-ketoglutarate dehydrogenase - ATP , NADH and succinyl CoA inhibit
86
How is pyruvate dehydrogenase regulated?
ATP, Acetyl CoA and NADH inhibit
Pyruvate and ADP activate
87
Phospholipids are composed of?
a phosphate group, a glycerol and fatty acids
88
What oils are rich in unsaturated fats?
plant oils
89
A function of cholesterol that does not harm health is its role _____.
as a component of animal cell membranes
90
What is the general formula for carbohydrates?
Cn(H2O)n
91
A carbohydrate that yields many monosaccharides when hydrolyzed is a ____?
polysaccharide
92
A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a ___?
carbohydrate
93
Lactose, the sugar in milk, is a ___
, because it can be split into two monosaccharides.
disaccharide
94
A ____ cannot be hydrolyzed any further. (carb)
monosaccharide
95
Glycogen is _____.
a polysaccharide found in animals
96
glucose + glucose —> _____ by _____.
maltose + water ... dehydration synthesis
97
_____ is the most abundant organic compound on Earth.
cellulose
98
What is another name for a condensation reaction?
dehydration
99
What is the name of the process during which a bond between two monomers is broken?
hydrolysis
100
hydrolysis is the opposite to?
condensation
101
Nucleic acid polymers are made up of ___ monomers.
nucleotide
102
Carbohydrate polymers are made up of ___ monomers.
simple sugar
103
Protein polymers are made up of
___ monomers.
amino acid
104
Energy is captured and stored in ____ bonds and is transferred to ____ following their ____
reduced (C=O, C-C, C-H)
ATP
oxidation
105
Explain how energy is harnessed from ATP
ATP is ionised in the cell and negative charges are crowded on the terminal phosphate, breaking bond releases energy
106
What is the free energy released on ATP hydrolysis used for
biological work
107
What releases the most energy in terms of phosphate removal from ATP
first phosphate i.e. ATP to ADP
108
What role does food play in the production of ATP?
ADP must be converted back to ATP, thus food is used as fuel to produce energy that is needed to convert ADP back to ATP.
109
Describe the general flow of energy through an organism
organic molecules in food - digestion and absorption - nutrient molecules in body cells - cellular respiration or carbon skeletons used for biosynthesis
110
What are the two major energy stores of the body
glycogen and fat
111
Explain how energy stores are metabolised to provide energy
proteins, triglycerides and gylcogen --> amino acids, glucose (gluconeogenesis) and fatty acids - blood stream - converted to acetyl coa - mitochondria to make ATP
112
List the three stages of catabolism
1. hydrolyse macromolecules
2. production of acetyl coa from building blocks
3. oxidation of acetyl coa to produce ATP
113
Describe the ATP ADP cycle
ATP to ADP requires input of H2O (hyrolysis) - exergonic
ADP to ATP releases H2O as byproduct (condensation reaction), endergonic (requires input of energy)
114
Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions?
γ -phosphate (the terminal phosphate)
(The γ -phosphate is the primary phosphate group on the ATP molecule that is hydrolyzed when energy is needed to drive anabolic reactions. Located the farthest from the ribose sugar, it has a higher energy than either the α - or β -phosphate.)
115
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
hydrolysis
116
Chemical energy is a form of _____ energy.
potential
117
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
cellular respiration
118
What are the by-products of cellular respiration?
heat, carbon dioxide, and water
119
If products have less potential energy, what type of reaction is this, what does it give off?
energy released to the surroundings - exergonic - releases heat. Occurs spontaneously - downhill
120
If products have more potential energy, what type of reaction is this?
reactants absorb energy from the surroundings, endergonic. - does not occur spontaneously - upward hill
121
The following reaction
A --> B + C + heat
is a(n) _____ reaction.
exergonic
122
A(n) _____ reaction occurs spontaneously.
exergonic
123
In cells, what is usually the immediate source of energy for an endergonic reaction?
ATP
124
The reaction ADP + P --> ATP is a(n) _____ reaction.
endergonic
125
The energy for an endergonic reaction comes from a(n) _____ reaction.
exergonic
126
What is the fate of the phosphate group that is removed when ATP is converted to ADP?
It is acquired by a reactant in an endergonic reaction. By acquiring the phosphate group the reactant acquires energy.
127
What is energy coupling?
the use of energy released from an exergonic reaction to drive an endergonic reaction
128
Where does glycolysis occur in the cell
the cytosol
129
Where are electrons transferred in the citric acid cycle?
The citric acid cycle transfers electrons to NADH and FADH2.
130
What is the final electron acceptor of cellular respiration
oxygen
131
The name given to the reaction of transfer of electrons in cellular respiration is given a special name. what is this name?
Redox reactions
132
In glycolysis, the carbon-containing compound that functions as the electron donor is?
Glucose
133
Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called?
pyruvate
134
What compound functions as the electron acceptor in glycolysis.
NAD+
135
The reduced form of the electron acceptor in glycolysis is?
NADH
136
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?
pyruvate, ATP and NADH
137
In glycolysis, ATP molecules are produced by _____.
substrate level phosphorylation - A phosphate group is transferred from glyceraldehyde phosphate to ADP.
138
Define substrate level phosphorylation
involves the addition of a phosphate group to another molecule. occurs in the cytoplasm in glycolysis and in the mitochondrial matrix in the CAC.
139
How many NADH are produced by glycolysis?
2
140
FADH2 is a product of?
the citric acid cycle
141
In glycolysis, what starts the process of glucose oxidation?
ATP
142
In glycolysis there is a net gain of _____ ATP.
2
143
In muscle cells, fermentation produces _____.
lactate and NAD+
144
In fermentation _____ is reduced and _____ is oxidized.
pyruvate ... NADH
(The pyruvate from glycolysis is reduced to either lactate or ethanol, and NADH is oxidized to NAD+.)
145
List the three types of pyruvate metabolism
lactate - fermentation in human muscle
ethanol - fermentation in yeast and bacteria
acetyl CoA - aerobic oxidation
146
In the presence of ___, human cells carry out ___ respiration, which yields ___. In the absence of oxygen, human cells can carry out ___, which yields ___. ___ and many ___ carry out ___, which takes place under ___ conditions, and produces ___.
oxygen, aerobic, acetyl CoA, lactic acid fermentation, lactate, yeasts, bacteria, alcohol fermentation, anaerobic, ethanol
147
What are the reactants of anaerobic lactic acid fermentation
NADH and pyruvate
148
What are the products of anaerobic lactic acid fermentation
NAD+ and lactate
149
Which term describes the degree to which an element attracts electrons?
electronegativity
150
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
anion and cation
151
What molecule enters the citric acid cycle?
acetyl coa
152
In the citric acid cycle, ATP molecules are produced by _____.
Substrate-level phosphorylation
- A phosphate group is transferred from GTP to ADP.
153
Name the products of the citric acid cycle
FADH2, NADH + H+, CO2, ATP
154
Draw out the citric acid cycle and show the carbon skeletons of each intermediate
//
155
in the cac pyruvate is oxidised to ?
CO2
156
In the cac NAD+ is reduced to?
NADH
157
in the cac FAD is reduced to ?
FADH2
158
Why is the citric acid cycle a cyclic pathway rather than a linear pathway?
It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA.
159
For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.
2 - Each glucose produces two pyruvates, each of which is converted into acetyl CoA
160
For each glucose that enters glycolysis, _____ NADH + H+ are produced by the citric acid cycle.
6 - 3 NADH + H+ are produced per each acetyl CoA that enters the citric acid cycle.
161
In cellular respiration, most ATP molecules are produced by _____.
oxidative phosphorylation
162
The final electron acceptor of cellular respiration is _____.
oxygen
163
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... intermembrane space
164
What is the function of ATP synthase
phosphorylates ADP
165
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
kinetic energy that is released as hydrogen ions diffuse down their concentration gradient
166
In mitochondrial electron transport, what is the direct role of O2 ?
to function as the final electron acceptor in the electron transport chain
167
How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.)
Both electron transport and ATP synthesis would stop.
Without O2 , mitochondria are unable to oxidize the NADH and FADH2 produced in the first three steps of cellular respiration, and thus cannot make any ATP via oxidative phosphorylation. In addition, without O2 the mitochondria cannot oxidize the NADH and FADH2 back to NAD+ and FAD , which are needed as inputs to the first three stages of cellular respiration.
168
why is more ATP made per molecule of NADH than per molecule of FADH2 ?
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor.
169
What is the effect of gramicidin on oxidative phosphorylation?
When the protein gramicidin is integrated into a membrane, an H+ channel forms and the membrane becomes very permeable to protons ( H+ ions).
170
If gramicidin is added to an actively respiring muscle cell, how would it affect the rates of electron transport, proton pumping, and ATP synthesis in oxidative phosphorylation?
- rate of ATP synthesis and size of proton gradient decreases
- electron transport rate, proton pumping rate and rate of oxygen uptake remains the same
171
___is a multi-protein complex within the electron transport chain.
Complex III
172
___donates electrons to the electron transport chain.
NADH
173
____ is a nonprotein organic electron carrier within the electron transport chain.
Q (ubiquinone)
174
___is a prosthetic group present in several components of the electron transport chain.
Fe-S
175
Of the electron transport compounds, list them in order from the one containing electrons with the highest free energy to the one containing electrons with the lowest free energy.
FADH2 -- FMN of Complex I -- Fe-S of Complex II -- Q -- Fe-S of Complex III -- Cyt c -- Cyt a of Complex IV -- O2
(not all listed here)
176
Approximately how much more free energy is supplied to the electron transport chain by NADH than by FADH2?
8 kcal/mol
177
What is the correct order of electron transport compounds from least electronegative to most electronegative?
NADH -- Fe-S of Complex I -- Q -- Fe-S of Complex III -- Cyt c-- Cyt a of Complex IV -- O2
178
Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. Why?
In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+, which is needed for the first three stages of cellular respiration.
179
Suppose that a cell’s demand for ATP suddenly exceeds its supply of ATP from cellular respiration. Explain what would happen how how ATP production is increased
ATP levels would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production.
180
How is glucose taken up into the cell?
facilitated transport with Na+
181
High Km is ___ affinity
low
182
What is the role of NAD+/NADH in cellular respiration?
The molecule acts as a shuttle for electrons during cellular respiration. At various chemical reactions, the NAD+ picks up an electron from glucose, at which point it becomes NADH. Then NADH, along with FADH2 will ultimately transport the electrons to the mitochondria, where the cell can harvest energy stored in the electrons.
