AP Bio unit 3
Which of the following is produced during the citric acid cycle? a. FAD b. Pyruvate c. Reduced electron carriers d. Lactic acid e. Water
c. Reduced electron carriers
The component of aerobic respiration that produces the most ATP per mole of glucose is a. the electron transport chain. b. the citric acid cycle. c. glycolysis. d. lactic acid fermentation. e. alcoholic fermentation.
a. the electron transport chain.
With the addition of the enzyme alcohol dehydrogenase, the rate of reduction of acetaldehyde to ethanol increases as the concentration of acetaldehyde is increased. Eventually, the rate of the reaction reaches a maximum, at which point further increases in the concentration of acetaldehyde have no effect. Why? a. All the alcohol dehydrogenase molecules are bound to acetaldehyde molecules. b. At high concentrations of acetaldehyde, the activation energy of the reaction increases. c. At high concentrations of acetaldehyde, the activation energy of the reaction decreases. d. The enzyme is no longer specific for acetaldehyde. e. At high concentrations of acetaldehyde, the change in free energy of the reaction decreases.
a. All the alcohol dehydrogenase molecules are bound to acetaldehyde molecules.
How do competitive and noncompetitive enzyme inhibitors differ? a. Competitive inhibitors bind to the active site, whereas noncompetitive inhibitors change the shape of the active site. b. Competitive inhibitors have a higher energy of activation than noncompetitive inhibitors have. c. They function at different pH values. d. Noncompetitive enzyme inhibitors contain magnesium, whereas competitive inhibitors contain iron. e. Noncompetitive enzyme inhibitors are reversible, whereas competitive inhibitors are irreversible.
a. Competitive inhibitors bind to the active site, whereas noncompetitive inhibitors change the shape of the active site.
Which of the following statements about NAD is true? a. It is a key electron carrier in redox reactions. b. It requires oxygen to function. c. It is found only in prokaryotes. d. It binds with an acetyl group to form acetyl CoA. e. It detoxifies hydrogen peroxide.
a. It is a key electron carrier in redox reactions.
The oxidizing agent at the end of the electron transport chain is a. O2. b. NAD+ c. ATP. d. FAD. e. ubiquinone.
a. O2.
Refer to figure 3-1. If end product E allosterically inhibits enzyme 1, what will be the result of a buildup of E in the cell? a. Reduced production of G b. Reduced production of A c. Reduced production of G d. Increased production of E e. Increased production of D
a. Reduced production of G
The electron transport chain contains four large protein complexes. These proteins a. are embedded in the inner membrane of the mitochondrion. b. change in a similar way when reduced. c. regulate the passage of water through the respiratory chain. d. oxidize NADH. e. complete oxidation of pyruvate to acetate
a. are embedded in the inner membrane of the mitochondrion.
Plants are green because a. chlorophylls absorb blue and orange-red wavelengths of light and reflect green light. b. chloroplasts transmit green light. c. energized chlorophyll a emits green light. d. plants do not possess green pigment. e. chlorophylls absorb green light.
a. chlorophylls absorb blue and orange-red wavelengths of light and reflect green light.
The enzyme rubisco is found in a. chloroplasts. b. mitochondria. c. the cytoplasm. d. the nucleus. e. yeast.
a. chloroplasts.
The hydrogen ion gradient is maintained by a. electron transport and proton pumping. b. the splitting of water. c. the ionization of glucose. d. ATP synthase. e. acetyl CoA.
a. electron transport and proton pumping.
In both photosynthesis and respiration, protons are pumped across a membrane during a. electron transport. b. photolysis. c. CO2 fixation. d. reduction of O2. e. glycolysis.
a. electron transport.
In all cells, glucose metabolism begins with a. glycolysis. b. fermentation. c. pyruvate oxidation. d. the citric acid cy
a. glycolysis.
The ability of an enzyme's active site to sometimes bind inhibitors that are larger than the substrate is called a. induced fit. b. enzyme flex. c. the lock and key paradox. d. substrate-induced active site shaping. e. enzyme retrofit.
a. induced fit.
. In human muscle cells, the fermentation process produces a. lactic acid. b. 12 moles of ATP. c. pyruvic acid. d. an excessive amount of energy. e. None of the above
a. lactic acid.
When NADH donates two electrons to ubiquinone during respiration, ubiquinone is a. reduced. b. oxidized. c. phosphorylated. d. aerobic. e. hydrolyzed
a. reduced.
If ΔG of a chemical reaction is negative, that reaction will a. release energy in the process. b. require the input of energy. c. not be spontaneous. d. not proceed. e. decrease the disorder in the system.
a. release energy in the process.
In the photosynthetic formation of ATP, the enzyme ATP synthase couples the synthesis of ATP to a. the diffusion of protons. b. the reduction of NADP+. c. the excitation of chlorophyll. d. the reduction of chlorophyll. e. CO2 fixation.
a. the diffusion of protons.
What can never be created or destroyed? a. Entropy b. Energy c. Free energy only d. Thermal energy only e. Potential energy only
b. Energy
. Refer to the diagram below. Which of the following was proved by experiments tracing isotopes of oxygen through the process of photosynthesis? a. CO2 is the source of the oxygen released during photosynthesis. b. All the oxygen gas produced during photosynthesis comes from water. c. The oxygen released by water is incorporated into glucose. d. Oxygen is needed to made rubisco. e. NADPH is made during the Calvin cycle.
b. All the oxygen gas produced during photosynthesis comes from water.
The drug 2,4-dinitrophenol (DNP) destroys the proton gradient across the inner mitochondrial membrane. What would be the effect of incubating isolated mitochondria in a solution of DNP? a. Oxygen would no longer be reduced to water. b. No ATP would be made during transport of electrons down the respiratory chain. c. Mitochondria would show a burst of increased ATP synthesis. d. Glycolysis would stop. e. Mitochondria would switch from glycolysis to fermentation.
b. No ATP would be made during transport of electrons down the respiratory chain.
How does the second law of thermodynamics apply to organisms? a. As energy transformations occur, free energy increases and unusable energy decreases. b. To maintain order, life requires a constant input of energy. c. The potential energy of chemical bonds can be converted to kinetic energy. d. Reactions occur only with an input of energy. e. It does not apply to organisms; the complexity of organisms contradicts the second law.
b. To maintain order, life requires a constant input of energy.
After the removal of carbon, the oxygen in CO2 ends up a. as atmospheric oxygen. b. attached to carbon and hydrogen to form sugar (G3P). c. in the soil. d. attached to hydrogen to form water. e. as rubisco.
b. attached to carbon and hydrogen to form sugar (G3P).
The process by which an end product acts as an inhibitor of the commitment step in a metabolic pathway is called a. feedback activation. b. feedback inhibition. c. positive feedback. d. concerted activation. e. competitive inhibition.
b. feedback inhibition.
When a molecule loses hydrogen atoms (as opposed to hydrogen ions), it becomes a. reduced. b. oxidized. c. redoxed. d. hydrogenated. e. hydrolyzed.
b. oxidized.
The role of oxygen gas in our cells is to a. catalyze reactions in glycolysis. b. produce CO2. c. form ATP. d. accept electrons from the respiratory chain. e. react with glucose to split water
b. produce CO2.
The rate of a chemical reaction in a cell is the measure of how a. often the reaction occurs. b. quickly the reaction reaches an end concentration of products c. much energy must be added to have the reaction occur. d. much activation energy is required to have the reaction occur. e. easily the reaction is inhibited.
b. quickly the reaction reaches an end concentration of products
When a photon is absorbed by a molecule, the photon a. loses its ability to generate any energy. b. raises the molecule from a ground state of low energy to an excited state. c. affects the molecule in ways that are not clearly understood. d. causes a change in the velocity of the wavelengths. e. None of the above
b. raises the molecule from a ground state of low energy to an excited state.
The statement "Enzymes are highly specific" means that certain a. enzymes are found in certain cells. b. reactions involving certain substrates are catalyzed by certain enzymes. c. enzymes require certain concentrations of substrates. d. reactions with certain activation energies are catalyzed by certain enzymes. e. concentrations of substrates work with certain enzymes.
b. reactions involving certain substrates are catalyzed by certain enzymes.
The photosynthetic pigment chlorophyll a absorbs a. infrared light. b. red and blue light. c. X rays. d. gamma rays. e. white light.
b. red and blue light.
The citric acid cycle a. has no connection with the respiratory chain. b. takes place in the mitochondrion. c. reduces two NAD+ for every glucose processed. d. produces no ATP. e. is the same thing as fermentation.
b. takes place in the mitochondrion.
Animals inhale air containing oxygen and exhale air with less oxygen and more carbon dioxide. Most of the carbon dioxide comes from a. hydrocarbons in the air b. the citric acid cycle c. glycolysis d. waste products e. All of the above
b. the citric acid cycle
The NADPH required for the reduction of 3PG to G3P comes from a. the dark reactions. b. the light reactions. c. the synthesis of ATP. d. the Calvin cycle. e. oxidative phosphorylation.
b. the light reactions.
An active site is a. the part of the substrate that binds with an enzyme. b. the part of the enzyme that binds with a substrate. c. the site where energy is added to an enzyme catalyst. d. the site where enzymes are found in cells. e. None of the above
b. the part of the enzyme that binds with a substrate
During the fermentation of one molecule of glucose, the net production of ATP is _______ molecule(s). a. one b. two c. three d. six e. eight
b. two
More free energy is released during the citric acid cycle than during glycolysis, but only 1 mole of ATP is produced for each mole of acetyl CoA that enters the cycle. Most of the remaining free energy produced during the citric acid cycle a. used to synthesize GTP. b. used to reduce electron carriers. c. lost as heat. d. used to reduce pyruvate. e. converted to kinetic energy.
b. used to reduce electron carriers.
In noncyclic photophosphorylation, electrons from _______ replenish chlorophyll molecules that have given up electrons. a. CO2 b. water c. NADPH + H+ d. O2 gas e. None of the above
b. water
When CO2 is added to RuBP, the first stable product synthesized is a. pyruvate. b. ribulose 1,5-bisphosphate. c. 3PG. d. ATP. e. glyceraldehyde 3-phosphate (G3P).
c. 3PG.
Which of the following is the balanced equation for the generation of sugar from sunlight, water, and CO2? a. 6 CO2 + 6 H2O --> C6H12O6 + O2 b. 6 CO2 + 12 H2O --> C6H12O6 + 6 O2 + 6 H2O c. 6 CO2 + 6 H2O --> C6H12O6 + 6 O2 d. 12 CO2 + 12 H2O --> 2 C6H12O6 + 2 O2 e. None of the above
c. 6 CO2 + 6 H2O --> C6H12O6 + 6 O2
Which type of inhibitor can be overcome completely by the addition of more substrate? a. Irreversible b. Noncompetitive c. Competitive d. Prosthetic e. Isotonic
c. Competitive
Which of the following processes occurs when oxygen is not available? a. Pyruvate oxidation b. The citric acid cycle c. Fermentation d. An electron transport chain e. All of the above
c. Fermentation
Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds. But trypsin only cuts next to lysine and elastase only cuts next to alanine. Why? a. Trypsin is a protein, and elastase is not. b. ∆G for the two reactions is different. c. The shape of the active site for the two enzymes is different. d. One of the reactions is endergonic, and the other is exergonic. e. Hydrolysis of lysine bonds requires water; hydrolysis of alanine bonds does not.
c. The shape of the active site for the two enzymes is different.
How do red and blue light differ from each other? a. They differ in intensity. b. They have a different number of photons in each quantum. c. Their wavelengths are different. d. They differ in duration. e. Red is radiant, whereas blue is electromagnetic.
c. Their wavelengths are different.
Which of the following statements about enzymes is false? a. They usually consist of proteins b. They change the rate of catalyzed reaction c. They change the ΔG of the reaction d. they are sensitive to heat e. they are sensitive to pH
c. They change the ΔG of the reaction
How does the reduction of pyruvate to lactic acid during fermentation allow glycolysis to continue in the absence of oxygen? a. Water is formed during this reaction. b. This reaction is a kinase reaction. c. This reaction is coupled to the oxidation of NADH to NAD+ d. This reaction is coupled to the formation of ATP. e. This reaction is coupled to the reduction of NAD+ to NADH.
c. This reaction is coupled to the oxidation of NADH to NAD+
The citric acid cycle begins with a. glucose. b. pyruvate. c. acetyl CoA. d. NADH + H+ e. ATP synthase.
c. acetyl CoA.
The function of NAD+ is to a. cause the release of energy to adjacent cells when energy is needed in aerobic conditions. b. hasten the release of energy when the cell has been deprived of oxygen. c. carry hydrogen atoms and free energy from compounds being oxidized, and to give hydrogen atoms and free energy to compounds being reduced. d. block the release of energy to adjacent cells. e. None of the above
c. carry hydrogen atoms and free energy from compounds being oxidized, and to give hydrogen atoms and free energy to compounds being reduced.
The precise moment when light energy is captured in chemical energy is the point at which a. light shines on chlorophyll. b. water is hydrolyzed. c. chlorophyll is oxidized. d. chlorophyll is reduced. e. the CO2 from air is captured in a sugar.
c. chlorophyll is oxidized.
. A conclusion of the first law of thermodynamics is that the total energy in the universe is a. decreasing. b. increasing. c. constant. d. being converted to free energy. e. being converted to matter.
c. constant
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane into the intermembranous space, the result is the a. formation of ATP. b. reduction of NAD+ c. creation of a proton gradient. d. restoration of the Na+-K +balance across the membrane e. reduction of glucose to latic acid
c. creation of a proton gradient.
A(n) _______ protein is a protein that has become nonfunctional due to the loss of its three-dimensional structure. a. permanent b. reversible c. denatured d. hydrolyzed e. environmentalized
c. denatured
The active site of an enzyme a. never changes shape b. forms no chemical bonds with substrates c. determines, by its structure, the specificity of the enzyme d. looks like a lump projecting from the surface of the enzyme e. changes the ΔG of the reaction
c. determines, by its structure, the specificity of the enzyme
According to the chemiosmotic theory, the energy for the synthesis of ATP as electrons flow down the respiratory chain is provided directly by the a. hydrolysis of GTP. b. reduction of NAD+ c. diffusion of protons. d. reduction of FAD. e. hydrolysis of ATP.
c. diffusion of protons.
Fermentation a. takes place in the mitochondrion. b. takes place in all animal cells. c. does not require O2. d. requires lactic acid. e. prevents glycolysis.
c. does not require O2.
Many species derive their energy from fermentation, which a. reduces NAD+ b. oxidizes CO2. c. ensures a continued supply of ATP. d. produces acetyl CoA. e. None of the above
c. ensures a continued supply of ATP.
When organisms move from one environment to another, they sometimes synthesize variations of existing enzymes, which are called a. coenzymes. b. abzymes. c. isozymes. d. effectors. e. activators.
c. isozymes.
In alcoholic fermentation, NAD+ is produced during the a. oxidation of pyruvate to acetyl CoA. b. reduction of pyruvate to lactic acid. c. reduction of acetaldehyde to ethanol. d. hydrolysis of ATP to ADP. e. oxidation of glucose.
c. reduction of acetaldehyde to ethanol.
In noncyclic photophosphorylation, water is used for the a. hydrolysis of ATP. b. excitation of chlorophyll. c. reduction of chlorophyll. d. oxidation of NADPH. e. synthesis of chlorophyll.
c. reduction of chlorophyll.
The molecule ATP is a. a component of most proteins. b. high in energy because of the presence of adenine. c. required for many energy-transforming biochemical reactions. d. a catalyst.
c. required for many energy-transforming biochemical reactions
Most ATP produced in our bodies is made a. by glycolysis. b. in the citric acid cycle. c. using ATP synthase. d. from photosynthesis. e. by burning fat.
c. using ATP synthase.
The O2 gas produced during photosynthesis is derived from a. CO2. b. glucose. c. water. d. CO. e. bicarbonate ions.
c. water
Which of the following statements about the reaction shown below is true? a. It is an endergonic reaction. b. The reactants have less energy than the products. c. ΔG is negative. d. The reaction can be reversed without the addition of energy. e. It is an anabolic reaction.
c. ΔG is negative.
How many moles of CO2 must enter the Calvin cycle for the synthesis of one mole of glucose? a. 1 b. 2 c. 3 d. 6 e. 12
d. 6
Figure 3-1 Refer to figure 3-1. If enzyme 2 is inactive, which end product will be produced from the metabolic pathway? a. C b. D c. F d. B e. G
d. B
Which of the following statement about the feedback inhibition of enzymes is false? a. It is usually exerted through allosteric effects. b. It is directed at the enzyme that catalyzes the commitment step in a metabolic pathway. c. It affects the rate of reaction, not the concentration of enzyme. d. It acts by permanently modifying the active site. e. It is an example of reversible inhibition.
d. It acts by permanently modifying the active site.
Which statement about pyruvate is false? a. It is the end product of glycolysis. b. It becomes reduced during fermentation. c. It is a precursor of acetyl CoA. d. It is a protein. e. It contains three carbon atoms.
d. It is a protein.
The exergonic reaction 1,3-diphosphoglycerate 3- phosphoglycerate is coupled to the reaction ADP + Pi ATP. Which of the following is most likely to be true about the reaction ADP + Pi ATP? a. The reaction never reaches equilibrium. b. The reaction is spontaneous. c. There is a large decrease in free energy. d. The reaction is endergonic. e. Temperature will not affect the rate constant of the reaction
d. The reaction is endergonic.
Which of the following statements about the exergonic hydrolysis of maltose to glucose is true? a. The reaction requires the input of free energy. b. The free energy of glucose is larger than the free energy of maltose. c. The reaction is not spontaneous. d. The reaction releases free energy. e. At equilibrium, the concentration of maltose is higher than the concentration of glucose.
d. The reaction releases free energy.
Oxidation and reduction a. entail the gain or loss of proteins. b. are defined as the loss of electrons. c. are both endergonic reactions. d. always occur together. e. proceed only under aerobic conditions
d. always occur together.
The main photosynthetic pigments in plants are _______ and _______. a. chlorophyll s; chlorophyll a b. chlorophyll x; chlorophyll y c. retinal pigment; accessory pigment d. chlorophyll a; chlorophyll b e. None of the above
d. chlorophyll a; chlorophyll b
During the first step of the citric acid cycle, energy stored in acetyl CoA is used to a. create a proton gradient. b. drive the reaction ADP + Pi --> ATP. c. reduce NAD+ to NADH. d. drive the reaction oxaloacetate --> citric acid. e. reduce FAD to FADH2.
d. drive the reaction oxaloacetate --> citric acid.
The binding of a substrate to an enzyme creates a(n) a. transition state b. activation groove c. catalyst d. enzyme-substrate complex e. energy barrier
d. enzyme-substrate complex
When the supply of acetyl CoA being produced exceeds the demands of the citric acid cycle, some of the acetyl CoA is diverted to the synthesis of a. pyruvate. b. NAD. c. proteins. d. fatty acids. e. lactic acid
d. fatty acids.
Before starch can be used for respiratory ATP production, it must be hydrolyzed to a. pyruvate. b. fatty acids. c. amino acids. d. glucose. e. oxaloacetate.
d. glucose.
The first pathway of photosynthesis, in which light energy is converted into chemical energy in the form of ATP and NADPH, is referred to as the a. light reductions b. dark reactions. c. carbon-fixation reactions. d. light reactions. e. None of the above
d. light reactions.
In the cell, the site of oxygen utilization is the a. nucleus. b. chloroplast. c. endoplasmic reticulum. d. mitochondrion. e. cytosol.
d. mitochondrion.
The water that is a by-product of cellular respiration is produced as a result of the a. combining of carbon dioxide with protons. b. conversion of pyruvate to acetyl CoA. c. degradation of glucose to pyruvate. d. reduction of oxygen at the end of the electron transport chain. e. None of the above
d. reduction of oxygen at the end of the electron transport chain.
The respiratory chain a. is located in the mitochondrial matrix. b. includes only peripheral membrane proteins. c. always produces ATP. d. reoxidizes reduced coenzymes. e. operates simultaneously with fermentation.
d. reoxidizes reduced coenzymes.
The chemiosmotic generation of ATP is driven by a. osmotic movement of water into an area of high solute concentration. b. the addition of protons to ADP and phosphate via enzymes. c. oxidative phosphorylation. d. the proton motive force. e. isocitrate dehydrogenase
d. the proton motive force.
Photosynthesis is the process that uses light energy to extract hydrogen atoms from a. glucose. b. chlorophyll. c. CO2. d. water. e. None of the above
d. water.
The light reactions of photosynthesis provides the Calvin cycle with a. protons and electrons. b. CO2 and glucose. c. water and photons. d. light and chlorophyll. e. ATP and NADPH.
e. ATP and NADPH.
Which statement about temperature effects is false? a. Raising the temperature may reduce the activity of an enzyme. b. Raising the temperature may increase the activity of an enzyme. c. Raising the temperature may denature an enzyme. d. Some enzymes are stable at the boiling point of water. e. All enzymes have the same optimal temperature.
e. All enzymes have the same optimal temperature.
The Calvin cycle uses _______ to produce glucose. a. CO2 b. ATP c. NADPH d. rubisco e. All of the above
e. All of the above
Which of the following statements about ATP is true? a. It is an energy-storage compound. b. It is the cell's principal compound for energy transfers. c. It stands for adenosine triphosphate. d. It is the molecule all living cells rely on to do chemical work. e. All of the above
e. All of the above
Which of the following statements about the electron transport chain is true? a. Electrons are received from NADH and FADH2. b. Electrons are passed from donor to recipient carrier molecules in a series of oxidation-reduction reactions. c. The terminal electron acceptor is usually oxygen. d. Most of the enzymes are part of the inner mitochondrial membrane. e. All of the above
e. All of the above
Which of the following does not happen in noncyclic electron transport? a. Oxygen gas is released. b. ATP forms. c. Water donates electrons and protons. d. NADPH forms. e. CO2 reacts with RuBP.
e. CO2 reacts with RuBP.
Which of the following statements about metabolic pathways is true? a. Complex chemical transformations in the cell occur in a single reaction. b. Each reaction requires ATP. c. In eukaryotes, they occur in the cytoplasm. d. They vary from organism to organism. e. Each one is regulated by specific enzymes
e. Each one is regulated by specific enzymes
Which statement about thermodynamics is true? a. Free energy is used up in an exergonic reaction. b. Free energy cannot be used to do work. c. The total amount of energy can change after a chemical transformation. d. Free energy can be kinetic but not potential energy. e. Entropy has a tendency to increase.
e. Entropy has a tendency to increase.
Which statement about oxidative phosphorylation is false? a. It forms ATP by the respiratory chain/ATP synthesis. b. It is brought about by chemiosmosis. c. It requires aerobic conditions. d. It takes place in mitochondria. e. Its functions can be served equally well by fermentation.
e. Its functions can be served equally well by fermentation.
In the conversion of succinate to fumarate, hydrogen atoms are transferred to FAD. The conversion of succinate and FAD to fumarate and FADH2 is an example of a. hydrolysis. b. an allosteric reaction. c. a metabolic pathway. d. an aerobic reaction. e. a redox reaction.
e. a redox reaction.
Photosynthesis and respiration have which of the following in common? a. In eukaryotes, both processes reside in specialized organelles. b. ATP synthesis in both processes relies on the chemiosmotic mechanism. c. Both involve electron transport. d. Both require light. e. a, b, and c
e. a, b, and c
Which of the following about enzymes is true? a. Enzymes are proteins b. Enzymes have specific amino acid sequence c. Enzymes highly specific d. Enzymes lower the energy barrier e. All of the above
e. all of the above
If the temperature of an enzyme-catalyzed reaction is increased from 40°C to 70°C, the rate of the reaction a. will increase indefinitely. b. will decrease immediately. c. will decrease to zero because the enzyme denatures. d. will decrease and then increase. e. cannot be determined without information regarding optimal temperature.
e. cannot be determined without information regarding optimal temperature.
A noncompetitive inhibitor inhibits binding of a substrate to an enzyme by a. binding to the substrate. b. binding to the active site. c. lowering the activation energy. d. increasing the ΔG of the reaction. e. changing the shape of the active site.
e. changing the shape of the active site.
Phosphorylation of ADP to ATP is endergonic, whereas the hydrolysis of ATP to ADP is exergonic. The two reactions are therefore said to be a. substrates. b. endergonic. c. kinetic. d. activated. e. coupled.
e. coupled.
The enzyme sucrose increases the rate at which starch is broken down into smaller oligosaccharides. It does this by a. decreasing the equilibrium constant of the reaction. b. increasing the change in free energy of the reaction. c. decreasing the change in free energy of the reaction. d. increasing the change in entropy of the reaction. e. lowering the activation energy of the reaction.
e. lowering the activation energy of the reaction.
Which of the following occurs during the light-independent reactions of photosynthesis? a. Water is converted into hydrogen and water. b. CO2 and water are converted into sugars and oxygen. c. Chlorophyll acts as an enzyme. d. Nothing occurs; the plant rests in the dark. e. None of the above
e. none of the above
Glycolysis a. takes place in the mitochondrion. b. produces no ATP. c. has no connection with the respiratory chain. d. is the same thing as fermentation. e. reduces two molecules of NAD+ for every glucose molecule processed.
e. reduces two molecules of NAD+ for every glucose molecule processed.
In the citric acid cycle, oxidative steps are coupled to a. oxidative phosphorylation. b. the oxidation of water. c. the oxidation of electron carriers. d. the hydrolysis of ATP. e. the reduction of electron carriers.
e. the reduction of electron carriers.
Enzymatic reactions can become saturated as substrate concentration increases because a. enzymes have the maximum possible number of hydrogen atoms attached to them. b. the concentration of substrate cannot increase any higher. c. substrates are inhibitors of enzymes. d. the activation energy of the reaction cannot be further lowered. e. there are a limited number of the enzyme molecules present.
e. there are a limited number of the enzyme molecules present.