Ap Bio Cellular Respiration Test

Front 1

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Back 1

It increases the surface for oxidative phosphorylation.

Front 2

Which statement best supports the hypothesis that glycolysis is an ancient metabolic pathway that originated before the last universal common ancestor of life on Earth?

Back 2

Glycolysis is widespread and is found in the domains Bacteria, Archaea, and Eukarya.

Front 3

Why are carbohydrates and fats considered high energy foods?

Back 3

They have a lot of electrons associated with hydrogen

Front 4

Which catabolic processes may have been used by cells on ancient Earth before free oxygen became available?

Back 4

Glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation, using an electron acceptor other than oxygen

Front 5

An electron loses potential energy when it

Back 5

Shifts to a more electronegative atom

Front 6

During cellular respiration, acetyl CoA accumulates in which location?

Back 6

mitochondrial matrix

Front 7

The transport of pyruvate into the mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion?

Back 7

active transport

Front 8

In prokaryotes, the respitory electron transport chain is located

Back 8

In the plasma membrane

Front 9

Which kind of metabolic poison would most directly interfere with glycolysis?

Back 9

An agent that closely mimics the structure of glucose but is not metabolized

Front 10

Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?

Back 10

mitochondrial intermebrane space

Front 11

Why is glycolysis described as having an investment phase and a payoff phase?

Back 11

It uses stored ATP and then forms a net increase in ATP

Front 12

Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?

Back 12

glycolysis

Front 13

Which of the following most accurately describes what is happening along the electron transport chain in figure 9.3?

Back 13

Each electron carrier alternates between being reduced and being oxidized.

Front 14

The ATP made during glycolysis is generated by

Back 14

substrate-level phosphorylation

Front 15

In a mitochondrion, if the matrix ATP concentration is high and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then

Back 15

ATP synthase will hydrolyze ATP and pump protons into the intermembrane space

Front 16

If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized by carbon dioxide and water, how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Back 16

12

Front 17

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

Back 17

oxidized

Front 18

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

Back 18

Oxidative phosphorylation (chemiosmosis)

Front 19

Chemiosmotic ATP synthesis (oxidative phosphorylation) occurs in

Back 19

All respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors.

Front 20

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

Back 20

oxidative phosphorylation

Front 21

Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part by the removal of a carbon from one molecule of pyruvate?

Back 21

Acetyl CoA

Front 22

When skeletal muscles cells are oxygen-deprived, the heart still pumps. What must the heart muscle cells be able to do?

Back 22

Continue aerobic metabolism when skeletal muscles cannot

Front 23

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

Back 23

It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms

Front 24

The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction

Back 24

loses electrons and loses potential energy

Front 25

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

Back 25

The more elctronegative atom is reduced, and energy is released

Front 26

What is proton-motive force?

Back 26

The force exerted on a proton by a transmembrane proton concentration gradient

Front 27

What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source?

Back 27

2/3

Front 28

Which of the following normally occurs regardless of whether or not oxygen is present?

Back 28

glycolysis

Front 29

Where are the proteins of the electron transport chain located?

Back 29

mitochondrial inner membrane

Front 30

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

Back 30

Energy released from movement of protons through ATP synthase, down the electrochemical gradient

Front 31

Which metabolic pathway is common to both cellular respiration and fermentation?

Back 31

glycolysis

Front 32

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electochemical gradient is an example of

Back 32

an endergonic reaction coupled to an exergonic reaction

Front 33

Inisde an active mitchondrion most electrons follow which pathway?

Back 33

citric acid cycle --> NADH --> electron transport chain --> oxygen

Front 34

A young animal never has much energy. He is brough to a veterinarian for help and is sent to an animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanatiion of his condition?

Back 34

His mitchondria lack the transport protein that moves pyruvate across the outer mitchondrial membrane

Front 35

The oxygen consumed during cellular respiration is involved directly in which process or event?

Back 35

Accepting electrons at the end of the electron transport chain

Front 36

During intense exercise, as the skeletal muscle cells go into anaerobiosis, the human body will increase its catabolism of

Back 36

carbohydrates only

Front 37

Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?

Back 37

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 38

Substrate-level phosphorylation accounts for approximately what precentage of the ATP formed by the reactions of glycolysis?

Back 38

100%

Front 39

In alcohol fermentation, NAD+ is regenerated from NADH by

Back 39

reduction of ecetaldehyde to ethanol (ethyl alcohol)

Front 40

An organism is discovered that thrives in bothe the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism

Back 40

is a faculative anaerobe

Front 41

You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body?

Back 41

It was released as CO2 and H2O

Front 42

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

Back 42

FADH2

Front 43

Where is ATP synthase located in the mitochondrion?

Back 43

inner membrane

Front 44

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

Back 44

NADH and pyruvate

Front 45

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

Back 45

the proton-motive force across the inner mitochondrial membrane

Front 46

Which of the following statements describes NAD+

Back 46

NAD+ is reduced to NADH during glycolysis, pyruvate oxiidation, and the citiric acid cycle

Front 47

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

Back 47

It is taken to the liver and converted back to pyruvate

Front 48

During aerobic repiration, electron travel downhill in which sequence?

Back 48

food --> citric acid cycle --> ATP --> NAD+

Front 49

Where does glycolysis take place in eukaryotic cells?

Back 49

cytosol

Front 50

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

Back 50

catabolic pathways

Front 51

When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by

Back 51

buildup of lactate

Front 52

In cellular respiration the energy for most ATP synthesis is supplied by

Back 52

A proton gradient across a membrane

Front 53

Brown fat cells produce a protein called thermogenin in their mitochondrial inner membrane. Thermogenin is a chennel for facilitated transport of protons across the membrane. What will occur in the brown fat cells when they produce thermogenin?

Back 53

ATP synthesis will decrease, and heat generation will increase

Front 54

During aerobic respiration H20 is formed. Where does the oxygen atom for the formation of the water come from?

Back 54

molecular oxygen (02)

Front 55

Starting with one molecule of glucose, the energy-containing products of glycolysis are

Back 55

2 NADH, 2 pyruvate, and 2 ATP

Front 56

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

Back 56

two

Front 57

The primary role of oxygen in cellular respiration is to

Back 57

act as an acceptor for electrons and hydrogen froming water

Front 58

A molecule that is phosphorylated

Back 58

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

Front 59

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

Back 59

creation of proton-motive force

Front 60

A mutationn in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells?

Back 60

The mutant yeast will be unable to grow anaerobically

Front 61

In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of

Back 61

ATP, CO2, and ethanol (ethyl alcohol)

Front 62

One function of bothe alcohol fermentation and latic acid fermentation is to

Back 62

reduce FADH2 to FAD+

Front 63

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

Back 63

substrate-level phosphorylation

Front 64

Which of the following statements describes the results of this reaction C6H1206 + 6CO2 --> 6CO2 + 6H20 + ENERGY ?

Back 64

C6H1206 is oxidized and O2 is reduced

Front 65

In glycolysis for each molecule of glucose oxidized to pyruvate

Back 65

two molecules of ATP are used and four molecules of ATP are produced

Front 66

How many oxygen molecules are required each time a molecule of glucose (C6H12O6) is completely oxidized to carbon dioxide and water via aerobic respiration?

Back 66

6

Front 67

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

Back 67

glycolysis and fermentation

Front 68

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free energy for the reuction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Back 68

Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis

Front 69

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

Back 69

Oxidative of pyruvate to acetyl CoA and the citric acid cycle

Front 70

During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate most of the potential energy contained in glucose is

Back 70

retained in two pyruvates

Front 71

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

Back 71

reduced

Front 72

Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose in aerobic cellular respiration?

Back 72

60-64