FREE AND STUDY GAMES ABOUT BIO TEST 2 CH 9

PDF Download

FREE AND STUDY GAMES ABOUT BIO TEST 2 CH 9

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -26 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Which of the following statements best describes the primary role played by oxygen in cellular respiration?

Answer:

It serves as the final acceptor for electrons from the electron transport chain.Question 2: When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes _____.

Answer:

Reduced Question 3: What happens when electrons are passed from one atom to a more electronegative atom?

Answer:

The more electronegative atom is reduced, and energy is released.Question 4: The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?

Answer:

coupling of an endergonic reaction to an exergonic reaction

Question 5: Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration?

Answer:

glucose ? NADH ? electron transport chain ? oxygen Question 6: In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO2, (2)

Answer:

acetyl CoA, NADH, and CO2

Question 7: Which electron carrier(s) function in the citric acid cycle?

Answer:

NADH and FADH2 Question 8: Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate?

Answer:

acetyl CoA Question 9: Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products?

Answer:

• NADH, 2 pyruvate, and 2 ATP

Question 10: If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure?

Answer:

Oxaloacetate will accumulate and citric acid will decrease.Question 11: Which of the following events takes place in the electron transport chain?

Answer:

the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle

Question 12: Approximately how many molecules of ATP are produced from the complete oxidation of one molecule of glucose (C6H12O6) in aerobic cellular respiration?

Answer:

30-32 Question 13: In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules?

Answer:

ATP, CO2, and ethanol (ethyl alcohol) Question 14: Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Answer:

It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.Question 15: Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

Answer:

100%

Question 16: The formula for cellular respiration

Answer:

C6H12O6 + 6O2 --> 6H2O + 6CO2 + ATP Question 17: Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?

Answer:

• ATP, 6 CO2, 9 NADH, and 3 FADH2

Question 18: In chemiosmosis, what is the most direct source of energy that is used to convert ADP +Pi to ATP?

Answer:

energy released from movement of protons through ATP synthase, down their electrochemical gradient

Question 19: Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

Answer:

oxidation of pyruvate to acetyl CoA and the citric acid cycle Question 20: High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of _____.

Answer:

allosteric regulation Question 21: Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction?

Answer:

It loses electrons and loses potential energy.Question 22: Which of the following statements about the electron transport chain is true?

Answer:

It consists of a series of redox reactions Question 23: Which of the summary statements below describes the results of the following reaction?C6H12O6 + 6 O2 ? 6 CO2 + 6 H2O + Energy

Answer:

C6H12O6 is oxidized and O2 is reduced.Question 24: Which kind of metabolic poison would most directly interfere with glycolysis?

Answer:

an agent that closely mimics the structure of glucose but is not metabolized Question 25: Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP.

Answer:

NADH