Test Bank Answers Ch.7 How Cells Harvest Energy From Food

Essentials of The Living World, 6e (Johnson)

Chapter 7 How Cells Harvest Energy from Food

1) Which of these is an electron carrier molecule?

A) NADH

B) ATP

C) adenylate kinase

D) carbonic acid

E) CO2

2) The first stage of cellular respiration, called ________, takes place in the cytoplasm of the cell and needs no oxygen.

A) glycolysis

B) Krebs cycle

C) photorespiration

D) oxidation

E) electron transport chain

3) Electrons, collected by electron carrier molecules from the Krebs cycle, are then used in

A) a fermentation pathway.

B) the formation of alcohol.

C) the electron transport chain.

D) the fluid portion of the mitochondrion.

E) glycolysis.

4) At the end product of glycolysis, what happens to pyruvate before it enters the Krebs cycle?

A) It is reduced.

B) It is phosphorylated.

C) It is carboxylated.

D) It is oxidized.

E) It is converted to alcohol.

5) Because ________ occurs without oxygen, scientists believe this stage in cellular respiration evolved first.

A) glycolysis

B) the Krebs cycle

C) the electron transport chain

D) fermentation

E) oxidative phosphorylation

6) Select the correct sequence of stages depicting the breakdown of glucose during cellular respiration.

A) glycolysis → pyruvate → acetyl-CoA → electron transport chain → Krebs cycle

B) glycolysis → pyruvate → acetyl-CoA → Krebs cycle → electron transport chain

C) pyruvate → glycolysis → acetyl-CoA → electron transport chain → Krebs cycle

D) Krebs cycle → glycolysis → pyruvate → acetyl-CoA → electron transport chain

E) electron transport chain → glycolysis → pyruvate → acetyl-CoA → Krebs cycle

7) Which statement accurately reflects the process of glycolysis?

A) It uses molecular oxygen but occurs in anaerobic environments.

B) It uses molecular oxygen and occurs in aerobic environments.

C) It uses no molecular oxygen and occurs in the mitochondria.

D) It uses no molecular oxygen but occurs in aerobic environments.

E) It uses no molecular oxygen and can occur in aerobic or anaerobic environments.

8) Which of the following is(are) produced during the Krebs cycle?

A) carbon dioxide

B) NADH

C) FADH2

D) ATP

E) All of the answer choices are correct.

9) Check all that describe the fermentation process.

A) occurs in the absence of oxygen

B) recycles NADH back to NAD+

C) produces FADH2

D) used by yeast to make alcohol

E) makes more ATP than cellular respiration

10) Under what environmental conditions do yeast carry out fermentation?

A) absence of oxygen

B) high temperature

C) low pH

D) high osmotic pressure

E) All of the answer choices are correct.

11) During which stage(s) of cellular respiration is CO2 produced?

A) glycolysis and Krebs cycle

B) Krebs cycle only

C) electron transport chain

D) oxidation of pyruvate to acetyl-CoA and Krebs cycle

E) Krebs cycle and the electron transport chain

12) After being made in glycolysis and the Krebs cycle, the NADH and FADH2 bring the electrons to

A) the electron transport chain.

B) water.

C) pyruvate.

D) the Calvin cycle.

E) the cytoplasm.

13) Which stage of cell respiration makes the majority of ATP?

A) glycolysis

B) Krebs cycle

C) electron transport chain

D) fermentation

E) They all produce the same amount of ATP.

14) Which macromolecules can be broken down into intermediate products that enter cellular respiration?

A) proteins

B) lipids

C) nucleic acids

D) carbohydrates

E) All of the answer choices are correct.

15) How many net ATP are made in glycolysis?

A) 1

B) 2

C) 6

D) 34

E) 38

16) Glycolysis takes place in the ________, and the Krebs cycle takes place in the ________.

A) mitochondrial matrix; inner mitochondrial membrane

B) cytoplasm; endoplasmic reticulum

C) intermembrane space of the mitochondria; mitochondrial matrix

D) cytoplasm; mitochondria matrix

E) mitochondria matrix; cytoplasm

17) Depending on your body's needs, acetyl-CoA is either directed into the Krebs cycle or

A) channeled into fat synthesis.

B) fermented into alcohol.

C) sent back to glycolysis.

D) sent to the electron transport chain.

E) fermented to lactic acid.

18) In glycolysis, glucose is cleaved into two, three-carbon molecules, called

A) lactate.

B) acetyl-CoA.

C) pyruvate.

D) oxaloacetate.

E) alcohol.

19) Which of the following groups compile the products of the Krebs cycle?

A) CO2 and ATP

B) CO2, ATP, and FADH2

C) ATP and NADH

D) CO2, ATP, NADH, and FADH2

E) ATP, NADH, and FADH2

20) The overall cellular respiration process

A) oxidizes glucose and reduces oxygen.

B) oxidizes oxygen and reduces glucose.

C) releases energy and reduces water.

D) requires energy and releases NADH.

E) releases energy and oxygen.

21) Yeast are used to make beer. What end products are produced when beer is made?

A) CO2 and ethanol

B) oxygen and ethanol

C) water, hydrogen gas, and ethanol

D) lactate and ethanol

E) ethanol and water

22) In a research article, you read of scientists measuring the amount carbon dioxide produced after a rat eats different types of food. Which part of cellular respiration are they studying?

A) glycolysis

B) the Krebs cycle

C) the electron transport chain

D) the Calvin cycle

E) chemiosmosis

23) Which of the following processes is not a reaction that cells use to obtain energy from nutrients?

A) cellular respiration

B) fermentation

C) photosynthesis

D) glycolysis

E) the Krebs cycle

24) The internal compartment of the mitochondria, involved in the electron transport chain, is the ________.

25) Amino acids from proteins undergo ________, the removal of the nitrogen side groups, prior to entering into the Krebs cycle.

26) During fermentation, ________ is recycled when hydrogens and electrons from NADH are donated to organic molecules in the absence of oxygen.

27) In fermentation, pyruvate is reduced to form organic compound products. Two of these common products are ________ and ________.

28) ATP is formed when ________ pass back across the membrane through ATP synthase channels.

29) During the second stage of cellular respiration, the ________ ________ takes place in the mitochondrial matrix and generates NADH and FADH2.

30) In cellular respiration, the complete oxidation of one glucose molecule provides a total of ________ molecules of ATP.

31) When a high-energy phosphate group is transferred from a substrate to ADP it is called ________ ________.

32) The Krebs cycle turns ________ times per glucose.

33) An electron carrier that is similar to NADH and also used in the Krebs cycle is ________.

34) When FAD and NAD+ gain electrons and hydrogens in cellular respiration stages, they are said to be ________.

35) Compare ethanol and lactic acid fermentation with regard to their products and the types of cells in which they occur.

36) In cellular respiration, organic molecules are oxidized when they lose electrons.

37) Pyruvate does not feed directly into the Krebs cycle. It is first decarboxylated and a coenzyme A is added to create acetyl-CoA. The enzyme that modifies the pyruvate molecule is called pyruvate

A) dehydrogenase.

B) kinase.

C) phosphatase.

D) reductase.

E) oxidase.

38) In the electron transport chain, ________ ________ receive electrons from electron carrier molecules and pump protons across the inner mitochondrial membrane.

39) Before fats and lipids can feed into the Krebs cycle, they are first broken down into glycerol chains.