cellular respiration. Flashcards
(184 cards)
1
Q
What is the term for paired oxidation and reduction reactions?
A
Oxidation reduction reactions or redox reactions
These reactions occur simultaneously, where oxidation strips electrons from one compound while reduction adds them to another.
2
Q
What happens to potential energy during oxidation?
A
It decreases
The removal of electrons from a molecule reduces its potential energy.
3
Q
What is the role of electron carriers in living systems?
A
They bind and carry high-energy electrons between compounds
This facilitates biochemical pathways.
4
Q
What is the oxidized form of nicotinamide adenine dinucleotide?
A
NAD+
NADH is the reduced form after it accepts electrons.
5
Q
What is the reduced form of flavin adenine dinucleotide?
A
FADH2
FAD+ is the oxidized form of this electron carrier.
6
Q
What is the primary function of ATP in living cells?
A
It serves as the energy currency of the cell
ATP is used to store and release energy as needed.
7
Q
How is energy released from ATP?
A
By the removal of its terminal phosphate group
This process is often linked to cellular work.
8
Q
What are the three components of ATP?
A
Adenine, ribose, and three phosphate groups
The structure of ATP includes these components, which are crucial for its function.
9
Q
What process breaks down ATP to release energy?
A
Hydrolysis
This involves the addition of water, resulting in ADP and inorganic phosphate.
10
Q
What is phosphorylation?
A
The addition of a phosphate group to a molecule
This process often involves ATP transferring its phosphate to other substrates.
11
Q
What is substrate-level phosphorylation?
A
A direct method of generating ATP during glucose breakdown
It involves transferring a phosphate group from an intermediate reactant to ADP.
12
Q
What is oxidative phosphorylation?
A
A complex process of ATP production involving chemiosmosis
This process generates most ATP during glucose catabolism and is oxygen-dependent.
13
Q
What is the primary site of oxidative phosphorylation in eukaryotic cells?
A
Mitochondria
The inner membrane of mitochondria contains the electron transport chain and ATP synthase.
14
Q
What is the significance of high-energy electrons in cellular energy transfer?
A
They allow energy transfer in small packages
This prevents destructive energy bursts within the cell.
15
Q
What happens to electrons during the reduction of carbon dioxide to methane?
A
Electrons are gained, increasing potential energy
This process is a reduction reaction.
16
Q
What is the general equation for the reduction of NAD+?
A
RH + NAD+ → NADH + R
RH acts as the reducing agent.
17
Q
What is the primary energy source for living cells?
A
Glucose
Nearly all of the energy used by living cells comes from the bonds of the sugar glucose.
18
Q
What is glycolysis?
A
The first step in the breakdown of glucose to extract energy for cellular metabolism.
19
Q
Is glycolysis an aerobic or anaerobic process?
A
Anaerobic.
20
Q
Where does glycolysis occur in the cell?
A
In the cytoplasm of both prokaryotic and eukaryotic cells.
21
Q
What are the two methods by which glucose enters heterotrophic cells?
A
- Secondary active transport
- GLUT proteins (glucose transporter proteins).
22
Q
What is the starting structure of glycolysis?
A
A six-carbon ring-shaped structure of a single glucose molecule.
23
Q
What are the end products of glycolysis?
A
2 pyruvate molecules, 2 NADH, and 2 ATP.
24
Q
What is the first step in glycolysis and what enzyme catalyzes it?
A
Phosphorylation of glucose catalyzed by hexokinase.
25
What is the role of hexokinase in glycolysis?
It phosphorylates glucose using ATP, producing glucose-6-phosphate.
26
What does the phosphorylation of glucose prevent?
It prevents the glucose molecule from leaving the cell.
27
What is an isomerase?
An enzyme that catalyzes the conversion of a molecule into one of its isomers.
28
What is produced in the third step of glycolysis?
Fructose-1,6-bisphosphate.
29
Which enzyme is a rate-limiting enzyme in glycolysis?
Phosphofructokinase.
30
What happens to fructose-1,6-bisphosphate in step four of glycolysis?
It is cleaved into two three-carbon isomers: dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.
31
What is the net investment of ATP by the end of the first half of glycolysis?
2 ATP molecules.
32
What is produced in the sixth step of glycolysis?
1,3-bisphosphoglycerate and NADH.
33
What is substrate-level phosphorylation?
The process of forming ATP by transferring a high-energy phosphate directly to ADP.
34
What is the final product of glycolysis?
Pyruvate.
35
What must happen to NADH to keep glycolysis continuing?
NADH must be oxidized back into NAD+.
36
What happens to glycolysis in the absence of oxygen?
Fermentation can provide the oxidation of NADH to NAD+.
37
What is the result of the seventh step in glycolysis?
Formation of one molecule of ATP and 3-phosphoglycerate.
38
What does the enzyme enolase do in glycolysis?
It catalyzes the formation of phosphoenolpyruvate (PEP) by dehydration.
39
What is the significance of pyruvate kinase in glycolysis?
It is a rate-limiting enzyme for the final step of glycolysis.
40
Fill in the blank: The last step in glycolysis results in the formation of _______.
Pyruvate.
41
True or False: Glycolysis produces a net gain of four ATP molecules per glucose molecule.
False.
42
What happens to mature mammalian red blood cells in the absence of glycolysis?
They lose their ability to maintain sodium-potassium pumps and eventually die.
43
What is the major function of acetyl CoA?
To deliver the acetyl group derived from pyruvate to the next stage of glucose catabolism.
## Footnote
Acetyl CoA is a key intermediate in cellular respiration.
44
What must happen to pyruvate before it enters the next pathway?
It must undergo a three-step conversion process.
## Footnote
This conversion prepares pyruvate for further metabolism in the mitochondria.
45
What is the first step in the conversion of pyruvate?
A carboxyl group is removed, releasing carbon dioxide.
## Footnote
This step results in a two-carbon hydroxyethyl group bound to the enzyme pyruvate dehydrogenase.
46
What is produced in step two of pyruvate conversion?
NADH is formed as the hydroxyethyl group is oxidized to an acetyl group.
## Footnote
The high-energy electrons from NADH will be used later to generate ATP.
47
What is the end product of the conversion of pyruvate?
Acetyl CoA.
## Footnote
This compound is crucial for entering the citric acid cycle.
48
What is the citric acid cycle also known as?
TCA cycle or Krebs cycle.
## Footnote
Named after Hans Krebs, who identified its steps in the 1930s.
49
Where does the citric acid cycle occur?
In the matrix of mitochondria.
## Footnote
Most enzymes of the cycle are soluble, except succinate dehydrogenase.
50
What are the main products of the citric acid cycle?
* Two carbon dioxide molecules
* One GTP/ATP
* Reduced carriers NADH and FADH2
## Footnote
The cycle is aerobic, relying on NADH and FADH2 for electron transfer.
51
What happens if NADH and FADH2 do not transfer their electrons?
The oxidation steps of the citric acid cycle do not occur.
## Footnote
Oxygen is essential for the continuity of the cycle.
52
What is the first step of the citric acid cycle?
The acetyl group combines with oxaloacetate to form citrate.
## Footnote
This step is irreversible and highly exergonic.
53
What occurs during step three of the citric acid cycle?
Isocitrate is oxidized to α-ketoglutarate, producing CO2 and NADH.
## Footnote
This step is regulated by ATP and NADH levels.
54
What is produced in step five of the citric acid cycle?
GTP or ATP is formed through substrate-level phosphorylation.
## Footnote
The specific product depends on the type of tissue.
55
What is the role of FAD in step six of the citric acid cycle?
FAD is reduced to FADH2.
## Footnote
This reduction occurs during the conversion of succinate to fumarate.
56
What happens in the final step of the citric acid cycle?
Malate is oxidized to regenerate oxaloacetate, producing NADH.
## Footnote
This allows the cycle to continue.
57
What is the amphibolic nature of the citric acid cycle?
It serves both catabolic and anabolic functions.
## Footnote
Intermediate compounds can be used to synthesize nonessential amino acids.
58
Fill in the blank: Each turn of the citric acid cycle produces three NADH molecules and one _____ molecule.
FADH2.
59
True or False: The citric acid cycle directly consumes oxygen.
False.
## Footnote
The cycle does not directly use oxygen but relies on it for the electron transport chain.
60
What are the two primary pathways in glucose catabolism that generate ATP?
Glycolysis and the citric acid cycle
## Footnote
These pathways generate ATP but most ATP is produced through oxidative phosphorylation.
61
What process begins the generation of ATP by moving electrons through electron carriers?
Electron transport chain
## Footnote
This process involves redox reactions and leads to the accumulation of hydrogen ions.
62
What is the role of ATP synthase in ATP production?
It phosphorylates ADP, producing ATP
## Footnote
ATP synthase uses the current of hydrogen ions diffusing through it.
63
What is the electron transport chain?
A series of redox reactions that pass electrons through complexes to reduce molecular oxygen
## Footnote
It is the last component of aerobic respiration.
64
How does oxygen enter plant tissues for respiration?
Through stomata
## Footnote
In animals, oxygen enters through various respiratory systems.
65
What are the four complexes in the electron transport chain labeled as?
Complexes I, II, III, and IV
## Footnote
These complexes are composed of proteins and are located in the inner mitochondrial membrane.
66
What does Complex I do in the electron transport chain?
Oxidizes NADH to NAD+ and pumps protons across the membrane
## Footnote
It helps establish the hydrogen ion gradient.
67
What is the role of ubiquinone in the electron transport chain?
It connects Complexes I and II to Complex III and carries electrons
## Footnote
Ubiquinone is lipid soluble and moves through the membrane.
68
How does Complex III contribute to ATP synthesis?
It pumps protons and transfers electrons to cytochrome c
## Footnote
Cytochrome c then transports electrons to Complex IV.
69
What is the function of Complex IV?
Holds oxygen tightly until it is reduced to water
## Footnote
It contains cytochrome proteins and copper ions.
70
What is chemiosmosis?
The process of using free energy from redox reactions to pump hydrogen ions across the mitochondrial membrane
## Footnote
It establishes an electrochemical gradient.
71
What is the significance of ATP synthase in chemiosmosis?
It allows protons to move back into the matrix and synthesizes ATP
## Footnote
ATP synthase acts as a generator powered by the proton gradient.
72
What effect does dinitrophenol (DNP) have on the inner mitochondrial membrane?
Makes it leaky to protons
## Footnote
DNP was historically used as a weight-loss drug.
73
What is oxidative phosphorylation?
The production of ATP through chemiosmosis in mitochondria
## Footnote
It accounts for 90% of ATP generated during aerobic glucose catabolism.
74
What is the final electron acceptor in the electron transport chain?
Molecular oxygen
## Footnote
Oxygen is reduced to water as part of the process.
75
What factors affect ATP yield from glucose catabolism?
Variations in proton pumping efficiency and electron shuttle mechanisms
## Footnote
Different tissues may use NAD+ or FAD+ as electron carriers.
76
What percentage of energy contained in glucose is extracted by living systems?
About 34 percent
## Footnote
The remainder is released as heat.
77
Fill in the blank: The enzyme in Complex I is called _______.
NADH dehydrogenase
78
True or False: Cytochrome c can carry pairs of electrons.
False
## Footnote
Cytochrome c accepts only one electron at a time.
79
What happens to the pH of the intermembrane space if cyanide inhibits cytochrome c oxidase?
Decrease
## Footnote
Cyanide poisoning would hinder ATP synthesis.
80
What is the fundamental difference between anaerobic cellular respiration and fermentation?
Anaerobic cellular respiration uses an inorganic molecule as the final electron acceptor, while fermentation uses an organic molecule.
81
What type of fermentation occurs in animal cells?
Lactic acid fermentation.
82
What initiates lactic acid fermentation in animal cells?
Insufficient oxygen supply or lack of mitochondria.
83
What is the final electron acceptor in aerobic respiration?
Oxygen molecule (O2).
84
What must happen to NADH if aerobic respiration does not occur?
NADH must be reoxidized to NAD+.
85
What is the role of fermentation in cellular metabolism?
To regenerate NAD+ from NADH to allow glycolysis to continue.
86
Which microorganisms use anaerobic respiration?
Certain prokaryotes, including some species in the domains Bacteria and Archaea.
87
What do methanogens reduce to oxidize NADH?
Carbon dioxide to methane.
88
What is produced by sulfate-reducing bacteria during anaerobic respiration?
Hydrogen sulfide.
89
What enzyme is used in lactic acid fermentation?
Lactate dehydrogenase (LDH).
90
What happens to lactic acid after it accumulates in muscles?
It is removed by blood circulation and transported to the liver for further metabolism.
91
What was once believed to be the cause of muscle stiffness and soreness?
Lactic acid accumulation.
92
What is the first reaction in alcohol fermentation?
Pyruvic acid + H+ → CO2 + acetaldehyde + NADH + H+ → ethanol + NAD+.
93
What enzyme catalyzes the first reaction of alcohol fermentation?
Pyruvate decarboxylase.
94
What is the coenzyme used in the first reaction of alcohol fermentation?
Thiamine pyrophosphate (TPP).
95
What is the variable ethanol tolerance range of yeast?
5 percent to 21 percent.
96
What type of anaerobes are Clostridia?
Obligate anaerobes.
97
What is a characteristic of facultatively anaerobic prokaryotes?
They can switch between aerobic respiration and fermentation depending on oxygen availability.
98
What do all forms of fermentation except lactic acid fermentation produce?
Gas.
99
What is the significance of gas production in fermentation?
It serves as an indicator of the fermentation of specific carbohydrates.
100
What is necessary for the sixth step in glycolysis?
An adequate supply of NAD+.
101
Fill in the blank: The chemical reaction of lactic acid fermentation involves the conversion of _______ to lactic acid.
Pyruvic acid.
102
What are the main metabolic pathways that interrelate with glycolysis?
Carbohydrates, proteins, and lipids
## Footnote
These pathways connect and allow for the conversion of various organic compounds into ATP.
103
Why are metabolic pathways not considered closed systems?
Substances enter from other pathways, and intermediates leave for other pathways
## Footnote
This allows for the continuous flow of substrates and products between different metabolic processes.
104
What is glycogen and its role in energy storage?
A polymer of glucose that stores energy in animals
## Footnote
Glycogen is stored in liver and muscle cells and can be hydrolyzed into glucose-1-phosphate when blood sugar levels drop.
105
What happens to glycogen when blood sugar levels drop?
It is hydrolyzed into glucose 1-phosphate (G-1-P)
## Footnote
This process allows for ATP production during periods of low blood sugar.
106
What are the components of sucrose?
A molecule of glucose and a molecule of fructose
## Footnote
Sucrose is a disaccharide linked by a glycosidic bond.
107
Which monosaccharides are absorbed directly into the bloodstream during digestion?
Glucose, fructose, and galactose
## Footnote
Galactose is part of the disaccharide lactose.
108
What must happen to amino acids before they can enter glucose catabolism pathways?
Their amino group must be removed
## Footnote
The amino group is converted into ammonia, which is then turned into urea in the liver.
109
What is urea and how is it formed?
A principal waste product in mammals formed from ammonia and carbon dioxide
## Footnote
Urea is excreted from the body in urine.
110
Which amino acids can be converted into pyruvate?
Alanine, glycine, threonine, cysteine, and serine
## Footnote
Pyruvate is an important intermediate in cellular respiration.
111
What are the products of amino acids leucine, lysine, phenylalanine, tyrosine, tryptophan, and isoleucine?
Converted into acetyl CoA
## Footnote
Acetyl CoA enters the citric acid cycle.
112
What role do triglycerides play in energy storage?
Long-term energy storage in animals
## Footnote
Triglycerides are composed of glycerol and three fatty acids.
113
What is beta-oxidation?
The process by which fatty acids are catabolized into acetyl groups
## Footnote
This process occurs in the mitochondria.
114
What is the significance of the citric acid cycle in metabolism?
It allows for the extraction of energy from carbohydrates, proteins, and lipids
## Footnote
Many metabolic intermediates feed into the citric acid cycle.
115
What is anoxygenic photosynthesis?
A form of photosynthesis that does not produce free oxygen
## Footnote
It can use substances like hydrogen sulfide instead of water.
116
What did the development of glycolysis allow early cells to do?
Extract energy from simple sugars accumulating in the environment
## Footnote
Glycolysis likely predates the evolution of oxygenic photosynthesis.
117
How did the rise of oxygen in the atmosphere affect cellular respiration?
It allowed aerobic respiration to evolve, enabling more energy extraction from sugars
## Footnote
Oxygenic photosynthesis led to an oxygenated atmosphere.
118
What is the effect of feedback inhibition on the production of an intermediate or product in a metabolic pathway?
It decreases the production of the intermediate or product by inhibiting the activity of key enzymes.
119
How is the rate of electron transport through the electron transport chain controlled?
It is controlled by the levels of ADP and ATP.
120
Why must cellular respiration be regulated?
To provide balanced amounts of energy in the form of ATP and generate intermediates for anabolism and catabolism.
121
What role do GLUT proteins play in glucose metabolism?
They transport glucose into specific tissues.
122
What happens to GLUT4 when insulin binds to its receptor?
GLUT4-containing vesicles fuse with the plasma membrane, allowing glucose to enter the cell.
123
How does having two different enzymes for a reversible reaction enhance control?
It allows for control of the reaction rate and prevents equilibrium from being reached.
124
What are allosteric effectors, and how do they affect enzyme activity?
They are molecules that bind to an allosteric site and can increase or decrease enzyme activity.
125
Name some common allosteric effectors that regulate enzyme activity.
* ATP
* ADP
* AMP
* NAD+
* NADH
126
What is the significance of hexokinase in glycolysis?
It catalyzes the phosphorylation of glucose, preventing it from leaving the cell.
127
Which enzyme is primarily controlled in glycolysis?
Phosphofructokinase.
128
What factors decrease the activity of phosphofructokinase?
* High levels of ATP
* Citrate
* Lower pH
129
What is the role of pyruvate kinase in glycolysis?
It catalyzes the last step, producing pyruvate, which can be further catabolized or converted to alanine.
130
How is pyruvate kinase regulated?
By phosphorylation and dephosphorylation, as well as by ATP levels.
131
What happens to pyruvate when more energy is needed?
It is converted into acetyl CoA via pyruvate dehydrogenase.
132
Which enzymes control the citric acid cycle?
* Isocitrate dehydrogenase
* α-ketoglutarate dehydrogenase
133
What effect do high levels of ATP and NADH have on the citric acid cycle?
They decrease the rates of reactions catalyzed by isocitrate dehydrogenase and α-ketoglutarate dehydrogenase.
134
What triggers a slowdown in the electron transport chain?
An increase in ATP concentration and a decrease in ADP concentration.
135
Fill in the blank: Glycolysis is primarily regulated at three key enzymatic steps, including hexokinase, phosphofructokinase, and _______.
phosphoglycerate kinase
136
True or False: The electron transport chain is affected by feedback inhibition.
False
137
What is the overall effect of increased levels of ADP on cellular respiration pathways?
It generally increases pathway activity.
138
What is the effect of elevated levels of glucose-6-phosphate on hexokinase activity?
It decreases hexokinase activity.
139
How does the citric acid cycle utilize α-ketoglutarate?
It can be used for amino acid synthesis when it accumulates.
140
What is acetyl CoA?
Combination of an acetyl group derived from pyruvic acid and coenzyme A, which is made from pantothenic acid (a B-group vitamin)
## Footnote
Acetyl CoA plays a critical role in metabolism, linking glycolysis and the citric acid cycle.
141
Define aerobic respiration.
Process in which organisms convert energy in the presence of oxygen
## Footnote
Aerobic respiration is essential for the efficient extraction of energy from nutrients.
142
What does anaerobic mean?
Process that does not use oxygen
## Footnote
Anaerobic processes are crucial for organisms that live in environments devoid of oxygen.
143
What is anaerobic cellular respiration?
Process in which organisms convert energy for their use in the absence of oxygen
## Footnote
This process includes fermentation as a key mechanism.
144
What is ATP synthase?
(also F1F0 ATP synthase) Membrane-embedded protein complex that adds a phosphate to ADP with energy from protons diffusing through it
## Footnote
ATP synthase is vital for ATP production during oxidative phosphorylation.
145
Define chemiosmosis.
Process in which there is a production of adenosine triphosphate (ATP) in cellular metabolism by the involvement of a proton gradient across a membrane
## Footnote
Chemiosmosis is a key mechanism in both photosynthesis and cellular respiration.
146
What is the citric acid cycle?
(also Krebs cycle) Series of enzyme-catalyzed chemical reactions of central importance in all living cells for extraction of energy from carbohydrates
## Footnote
The citric acid cycle is a crucial metabolic pathway that produces electron carriers used in oxidative phosphorylation.
147
What does dephosphorylation mean?
Removal of a phosphate group from a molecule
## Footnote
Dephosphorylation is an important regulatory mechanism in cellular signaling.
148
What is fermentation?
Process of regenerating NAD+ with either an inorganic or organic compound serving as the final electron acceptor; occurs in the absence of oxygen
## Footnote
Fermentation allows glycolysis to continue by replenishing NAD+, enabling energy production in low-oxygen conditions.
149
What is a GLUT protein?
Integral membrane protein that transports glucose
## Footnote
GLUT proteins are essential for glucose uptake in various tissues.
150
Define glycolysis.
Process of breaking glucose into two three-carbon molecules with the production of ATP and NADH
## Footnote
Glycolysis is the first step in cellular respiration and occurs in the cytoplasm.
151
What is an isomerase?
Enzyme that converts a molecule into its isomer
## Footnote
Isomerases play a critical role in metabolic pathways by facilitating structural changes in compounds.
152
What is the Krebs cycle?
(also citric acid cycle) Alternate name for the citric acid cycle, named after Hans Krebs
## Footnote
The cycle is named after Hans Krebs, who identified the steps in the pathway in the 1930s.
153
What is oxidative phosphorylation?
Production of ATP using the process of chemiosmosis in the presence of oxygen
## Footnote
Oxidative phosphorylation is the final stage of cellular respiration, occurring in the mitochondria.
154
Define phosphorylation.
Addition of a high-energy phosphate to a compound, usually a metabolic intermediate, a protein, or ADP
## Footnote
Phosphorylation is a key regulatory mechanism in cellular metabolism.
155
What is a prosthetic group?
(also prosthetic cofactor) Molecule bound to a protein that facilitates the function of the protein
## Footnote
Prosthetic groups are crucial for the activity of many enzymes.
156
What is pyruvate?
Three-carbon sugar that can be decarboxylated and oxidized to make acetyl CoA
## Footnote
Pyruvate is the end product of glycolysis and serves as a key link to the citric acid cycle.
157
What is a redox reaction?
Chemical reaction that consists of the coupling of an oxidation reaction and a reduction reaction
## Footnote
Redox reactions are fundamental to energy transfer in biological systems.
158
What is substrate-level phosphorylation?
Production of ATP from ADP using the excess energy from a chemical reaction and a phosphate group from a reactant
## Footnote
Substrate-level phosphorylation occurs during glycolysis and the citric acid cycle.
159
What is the TCA cycle?
(also citric acid cycle) Alternate name for the citric acid cycle, named after the group name for citric acid, tricarboxylic acid (TCA)
## Footnote
The TCA cycle is essential for aerobic energy production in cells.
160
What is ubiquinone?
Soluble electron transporter in the electron transport chain that connects the first or second complex to the third
## Footnote
Ubiquinone is a vital component in the mitochondrial electron transport chain.
161
What is the primary function of ATP in cells?
ATP functions as the energy currency for cells, allowing the storage and transport of energy.
162
What is the structure of ATP?
ATP is an RNA nucleotide with three phosphates attached.
163
What happens to ATP when it is used for energy?
A phosphate group or two are detached, producing either ADP or AMP.
164
How is ADP converted back into ATP?
Energy derived from glucose catabolism is used to convert ADP into ATP.
165
What is phosphorylation?
Phosphorylation is the process where the third phosphate of ATP is temporarily attached to a substrate.
166
What are the two processes of ATP regeneration associated with glucose catabolism?
* Substrate-level phosphorylation
* Oxidative phosphorylation through chemiosmosis
167
What is glycolysis?
Glycolysis is the first pathway in the cytoplasm for breaking down glucose to extract energy.
168
How many parts does glycolysis consist of?
Glycolysis consists of two parts.
169
What occurs in the first part of glycolysis?
The six-carbon ring of glucose is prepared for cleavage into two three-carbon sugars, with ATP invested.
170
What occurs in the second part of glycolysis?
ATP and high-energy electrons are extracted from hydrogen atoms and attached to NAD+.
171
What is the net gain of glycolysis?
The net gain is two ATP and two NADH molecules.
172
What happens to pyruvate in the presence of oxygen?
Pyruvate is transformed into an acetyl group attached to coenzyme A, forming acetyl CoA.
173
What is produced during the conversion of pyruvate into acetyl CoA?
A molecule of carbon dioxide and two high-energy electrons are removed.
174
What does the citric acid cycle involve?
It involves a series of redox and decarboxylation reactions that remove high-energy electrons and carbon dioxide.
175
What are the end products of the electron transport chain?
The end products are water and ATP.
176
What role does oxygen play in aerobic respiration?
Oxygen is the final electron acceptor in the electron transport chain.
177
What happens to the energy of electrons in the electron transport chain?
Electrons gradually lose energy as they pass through the chain.
178
What is fermentation?
Fermentation is a process used to regenerate NAD+ when NADH cannot be oxidized through aerobic respiration.
179
What is a key characteristic of fermentation related to ATP?
The regeneration of NAD+ in fermentation is not accompanied by ATP production.
180
What simple sugars are catabolized during glycolysis?
* Galactose
* Fructose
* Glycogen
* Pentose
181
How do amino acids connect with glucose catabolism?
Amino acids connect through pyruvate, acetyl CoA, and components of the citric acid cycle.
182
What is the regulation of cellular respiration primarily controlled by?
The regulation is primarily controlled by specific enzymes in the pathways.
183
What mechanism is used to control enzyme activity in cellular respiration?
A negative feedback mechanism is used to turn enzymes off.
184
Which nucleosides affect the enzymes in the respiration processes?
* ATP
* ADP
* AMP
* NAD+
* FAD
