cellular energetics

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Based on the graph, what is the approximate optimal pH for enzyme B?

10

Given the information provided in the table, which of the following predictions is most likely?

Mice have the ability to detect a greater number of odorants than humans.

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Which of the following best describes the process of induced fit?

A substrate binds to the active site of an enzyme, causing the conformation of the active site to change slightly.

IDH is allosterically activated by ADP at high concentrations. Which of the following best describes how this interaction helps regulate the Krebs cycle?

High levels of ADP stimulate the Krebs cycle, leading to the increased conversion of ADP to ATP during oxidative phosphorylation.

Which of the following statements about letter B is true?

Letter B represents the activation energy of the catalyzed reaction pathway.

Consider a reaction in which reactants X and Y combine to form the product Z. The diagram below compares the reaction coordinates for the catalyzed and uncatalyzed pathways of this reaction. Which of the following statements about letter C is true?

Letter C represents the activation energy of the uncatalyzed reaction pathway.

Which of the following statements describes a likely result of this clustering?

Pathway intermediates are prevented from entering alternative metabolic pathways.

Which of the following would most likely result if pepsin's environmental temperature was lowered from 37C to 25C

Pepsin would be less efficient at catalyzing reactions.

Which of the following best describes how the Calvin cycle and the light reactions of photosynthesis function together?

The Calvin cycle uses ATP and NADPH generated by the light reactions to synthesize carbohydrates.

Based on the data above, which type of wheat is the best choice to grow in this region, and why?

Type 3, because the diversity of NB-LRR immune receptors in this type make it more likely to survive and reproduce in the region.

Which of the following occurs immediately after the electrons from PSII are captured by the primary electron acceptor?

Water is broken down.

Which of the following statements best describes the process carried out by glutamine synthetase?

Glutamine synthetase uses an exothermic reaction to drive an endothermic one by catalyzing the formation of a phosphorylated intermediate.

Which of the following best describes what happens when maltose binds with maltase?

Maltose binds to the active site of maltase, causing the conformation of the active site to change slightly.

Which of the following terms best describes cyanide?

Noncompetitive inhibitor

Based on the information above, which of the following best describes an effect of rising ADP levels in mitochondria?

Oxygen consumption will increase.

Which of the following claims is best supported by the results of the study described above?

The level of ATP in mutant flies is correlated with the severity of the phenotype seen in those flies

Which of the following statements accurately describes an energy-releasing process that is coupled to an energy-requiring process in the cell?

The movement of motor proteins is powered by the formation of ADP and inorganic phosphate from ATP.

Which of the following statements is true?

The organization seen in living cells, tissues, and organs is maintained by a constant input of energy.

Which of the following claims is best supported by the experimental results described above?

The product of the reaction catalyzed by Enzyme 2 is efficiently transferred to Enzyme 3.

Based on the data above, which of the following best describes what happens to the rate of product formation at higher initial substrate concentrations?

The rate of product formation levels off because nearly all of the enzyme is bound to substrate.

Based on the data above, which of the following best predicts how the rate of product formation will change if the initial substrate concentration is increased from 0.7M to 1.0M

The rate of product formation will not change significantly.

Which of the following best describes what will result when a glucose-fed yeast cell is placed in an anaerobic environment?

The yeast cell will produce ATP through fermentation, generating CO2 and ethanol as byproducts.

Which of the following pieces of evidence best supports the claim that the wild type version of the gene described above is not essential for ATP synthase function?

There is no lethal phenotype associated with a null mutation in the gene.

Which of the following insects from the population described above is likely to be most reproductively successful?

an insect with Variants 2 and 3

Based on the information provided, which of the following photosynthetic organisms can best absorb the wavelengths of light present at depths of 25 and 100 meters?

an organism with chlorophyll a and phycoerythrin

Based on the information above, which of the following is the most likely explanation for how cyanide causes histotoxic hypoxia?

cyanide inhibits the transfer of electrons to the final acceptor the electron transport chain

A newly discovered gene mutation causes fruit flies to have ATP synthase levels that are about one-third of normal. Based on the information presented in Figure 1, which of the following describes a likely outcome for a population made up of these flies?

~70%, percent of flies in the mutant population will die before reaching adulthood because the supply of ATP will not meet energy demands.

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Which of the following drugs would be most likely to prevent cavities caused by S. mutans?

A drug that prevents the conversion of glucose into pyruvate

Which of the following best explains how the light reactions of photosynthesis generate ATP?

A proton gradient drives the formation of ATP from ADP and inorganic phosphate via ATP synthase.

Which of the following toxins would be most likely to disrupt carbohydrate metabolism in Bacteroides species?

A toxin that inhibits the function of an enzyme during glycolysis

Which of the following best describes the effect AChE has on the hydrolysis of ACh?

AChE decreases activation energy of ACh hydrolysis, increasing the rate of this reaction

Which of the following best indicates that the light reactions of photosynthesis have completed and that the Calvin cycle has begun?

ATP and NADPH accumulate in the stroma.

Which of the following explains the most likely effect of this toxin on the light reactions of photosynthesis?

ATP synthesis will not occur.

Based on the model of the Krebs cycle shown above, which of the following best describes an effect of gifblaar poisoning?

ATP would be depleted, inhibiting many biological processes.

Which of the following explains the most likely effect this toxin will have on the Calvin cycle?

Carbon dioxide will not be converted into carbohydrates.

Which of the following terms best describes methotrexate?

Competitive inhibitor

A solution of enzyme A has a pH of 8. Based on the graph, which pH change would result in higher enzyme activity?

Decreasing the pH of the solution to 6

Based on the information provided, which of the following statements is true?

During glutamine synthesis, an exothermic reaction provides energy to drive an endothermic reaction.

Which of the following best explains why ptyalin is able to break down starches, but not proteins?

Enzymes are specific to their substrates.

Which of the following best explains why pancreatic amylase is able to break down starches, but not lipids?

Enzymes bind only to their specific substrates.

Figure 1. Enzymatic activity of BP-I and BP-II over a range of enzyme concentrations. Based on the information provided above, which of the following statements is most likely true?

The active site of BP-I is slightly different from that of BP-II, so the two enzymes function differently at most concentrations.

Which of the following best explains how the addition of an enzyme would affect the above reaction?

The enzyme would decrease the activation energy of the reaction, increasing its rate

Which of the following statements describes a likely effect of the channel on the process carried out by tryptophan synthase?

The indole molecule does not diffuse across the cell membrane before it can be used by the beta subunit.

Which of the following statements best justifies the claim that the processes carried out by the fungus are consistent with the second law of thermodynamics?

The total amount of entropy in the universe increases when heat is released from fungus into the environment

Both adult and fetal hemoglobin contain alpha chain subunits. According to the information provided, which of the following diagrams is the most likely representation of fetal and adult hemoglobin?

adult: gray pink fetal: pink orange

Based on the information above, which of the following is most likely true about RBCs?

RBCs generate lactate as a waste product.

Which of the following conclusions is best supported by the results of the experiment?

An increase in light intensity increases the rate of photosynthesis.

Which of the following conclusions is best supported by the results of the experiment?

As light intensity decreases, the production of photosynthetic products decreases.

Which of the following best explains why trypsin is not active at high temperatures?

At high temperatures, trypsin loses its tertiary and secondary structures.