Biology 121 Chapter 9

Front 1

When electrons move closer to a more electronegative atom, what happens

Back 1

Energy is released
The more electronegative atom is reduced

Front 2

Why does the oxidation of organic compounds by molecular oxygen to produce CO2and water release free energy?

Back 2

Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).

Front 3

When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

Back 3

oxidized

Front 4

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes

Back 4

reduced

Front 5

Which of the following statements describes NAD+?

Back 5

NAD+is reduced to NADH during both glycolysis and the citric acid cycle

Front 6

An electron loses potential energy when it

Back 6

shifts to a more electronegative atom

Front 7

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis

Back 7

100%

Front 8

During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is

Back 8

retained in the pyruvate

Front 9

In addition to ATP, what are the end products of glycolysis

Back 9

NADH and pyruvate

Front 10

Starting with one molecule of glucose, the "net" products of glycolysis are

Back 10

2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O

Front 11

In glycolysis, for each molecule of glucose oxidized to pyruvate

Back 11

2 molecules of ATP are used and 4 molecules of ATP are produced

Front 12

A molecule that is phosphorylated

Back 12

has an increased chemical reactivity; it is primed to do cellular work

Front 13

How does pyruvate enter the mitochondrion?

Back 13

active transport

Front 14

During cellular respiration, acetyl CoA accumulates in which location

Back 14

mitochondrial matrix

Front 15

How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?

Back 15

2

Front 16

How many molecules of carbon dioxide (CO2) would be produced by five turns of the citric acid cycle?

Back 16

10

Front 17

Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle?

Back 17

3 ATP, 6 CO2, 9 NADH, and 3 FADH2

Front 18

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

Back 18

oxidation of pyruvate to acetyl CoA and the citric acid cycle

Front 19

For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced

Back 19

12

Front 20

Cellular respiration harvests the most chemical energy from which of the following

Back 20

chemiosmotic phosphorylation

Front 21

Where are the proteins of the electron transport chain located

Back 21

mitochondrial inner membrane

Front 22

During aerobic respiration, which of the following directly donates electrons to the electron transport chain atthe lowest energy level?

Back 22

FADH2

Front 23

The primary role of oxygen in cellular respiration is to

Back 23

act as an acceptor for electrons and hydrogen, forming water.

Front 24

Inside an active mitochondrion, most electrons follow which pathway

Back 24

citric acid cycle NADH electron transport chain oxygen

Front 25

During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from

Back 25

molecular oxygen (O2)

Front 26

Energy released by the electron transport chain isused to pump H+ ions into which location?

Back 26

mitochondrial intermembrane space

Front 27

The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is

Back 27

the difference in H+concentrations on opposite sides of the inner mitochondrial membrane.

Front 28

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the

Back 28

creation of a proton gradient

Front 29

It is possible to prepare vesicles from portions of the inner membrane of the mitochondrial components. Which one of the following processes could still be carried on by this isolated inner membrane

Back 29

oxidative phosphorylation

Front 30

Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required

Back 30

6

Front 31

Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?

Back 31

oxidative phosphorylation (chemiosmosis)

Front 32

Approximately what percentage of the energy of glucose (C6H12O6) is transferred to storage in ATP as a result of the complete oxidation of glucose to CO2and water in cellular respiration?

Back 32

40%

Front 33

Which of the following couples chemiosmosis to energy storage

Back 33

ATP synthase

Front 34

Which of the following normally occurs whether or not oxygen (O2) is present?

Back 34

glycolysis

Front 35

Which of the following occurs in the cytosol of a eukaryotic cell?

Back 35

glycolysis and fermentation

Front 36

Which metabolic pathway is common to both cellular respiration and fermentation

Back 36

glycolysis

Front 37

The ATP made during fermentation is generated by which of the following

Back 37

substrate-level phosphorylation

Front 38

One function of both alcohol fermentation and lactic acid fermentation is to

Back 38

oxidize NADH to NAD+

Front 39

Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

Back 39

It is found in the cytosol, does not involve oxygen, and is present in most organisms.

Front 40

Muscle cells, when an individual is exercising heavily and when the muscle becomes oxygen deprived, convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells

Back 40

it is taken to the liver and converted back to pyruvate

Front 41

What is the purpose of beta oxidation in respiration?

Back 41

breakdown of fatty acids

Front 42

Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle?

Back 42

acetyl CoA

Front 43

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

Back 43

glycolysis

Front 44

In mitochondria, exergonic redox reactions

Back 44

provide the energy that establishes the proton gradient

Front 45

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

Back 45

The pH of the matrix increases

Front 46

Cells do not catabolize carbon dioxide because

Back 46

CO2 is already completely oxidized

Front 47

Which of the following is a true distinction between fermentation and cellular respiration?

Back 47

NADH is oxidized by the electron transport chain in respiration only

Front 48

What is the term for metabolic pathways that release stored energy by breaking down complex molecules?

Back 48

catabolic pathways