Respiration

Question 1

located in the lipid interior of the membrane, ferries electrons from Complex I to Complex III, which contains cytochrome b

Answer 1

Ubiquinone/coenzyme Q (CoQ)

Question 2

plays a critical role in both catabolic and anabolic processes and represents a major “hub” of metabolic activities in the cell

Answer 2

citric acid cycle

Question 3

can undergo glycolysis once they have been converted to glucose 6-phosphate or fructose 6-phosphate

Answer 3

Carbohydrates other than glucose, including glycogen, starch, various disaccharides, and a number of monosaccharides

Question 4

a peripheral membrane protein on the intermembrane-space side that shuttles back and forth between Complexes III and IV

Answer 4

cytochrome c

Question 5

non-heme iron proteins that are additional components of the electron transport chain

Answer 5

iron-sulfur proteins

Question 6

(exergonic) various pathways by which different organic molecules are broken down to yield energy

Answer 6

catabolism

Question 7

is a key intermediate in cellular energy metabolism because it can be utilized in one of several pathways

Answer 7

Pyruvate

Question 8

 Electrons Removed from the Glucose Molecule Are Transferred to Oxygen
 a series of electron carriers, each of which holds the electrons at a slightly lower energy level than the previous carrier

Answer 8

electron transport chain

Question 9

phase that requires an energy investment of 2 ATP per glucose molecule. This stage ends with the splitting of the six-carbon sugar molecule into two three-carbon molecules.

Answer 9

Preparatory Phase

Question 10

– was originally known as the Krebs cycle in honor of Sir Hans Krebs, whose research group was largely responsible for its elucidation; Krebs cycle is more commonly called the citric acid cycle or the TCA (tricarboxylic acid) cycle today, because it begins with the formation of citric acid, or citrate, which has three carboxylic acid (—COO-) groups

Answer 10

citric acid cycle

Question 11

central to the biosynthetic processes of life

Answer 11

pyruvate or the acetyl group of acetyl CoA

Question 12

which receives two electrons from NADH and passes them to CoQ

Answer 12

flavin mononucleotide (FMN)

Question 13

Oxidizes the Acetyl Groups of the Acetyl CoA Molecules

Answer 13

citric acid cycle

Question 14

depends on a gradient of protons (H+ ions) across the mitochondrial membrane and the subsequent use of the free energy stored in that gradient to form ATP from ADP and phosphate

Answer 14

Oxidative Phosphorylation

Question 15

serve as an intermediate between two-electron carriers and one-electron carriers

Answer 15

ubiquinone, also called coenzyme Q (CoQ)

Question 16

represent the cell’s net energy harvest from glycolysis

Answer 16

ATP & NADH

Question 17

phase that produces an energy yield of 4 ATP and 2 NADH—a substantial return on the original investment. The net ATP yield is therefore 2 molecules of ATP per molecule of glucose.

Answer 17

payoff phase

Question 18

drives the formation of ATP from ADP and Pi by oxidative phosphorylation

Answer 18

proton gradient

Question 19

two distinct events take place in chemiosmotic coupling:

Answer 19

(1) a proton gradient is established across the inner membrane of the mitochondrion, and
(2) potential energy stored in the gradient is used to generate ATP from ADP and phosphate

Question 20

the complete oxidation of sugars or other organic molecules to carbon dioxide and water

Answer 20

Respiration

Question 21

the combination of the acetyl group and CoA and is the form in which carbon atoms from glucose enter the citric acid cycle

Answer 21

acetyl CoA

Question 22

the overall reaction for the complete oxidation of glucose

Answer 22

C6H12O6 + 6O2 ⎯→ 6CO2 + 6H2O + Energy

Question 23

— a large molecule consisting of a nucleotide linked to pantothenic acid, one of the B-complex vitamins
— often written as CoA-SH to indicate its sulfur group, where bonding occurs

Answer 23

coenzyme A (CoA)

Question 24

electron acceptor; the first component of the electron transport chain

Answer 24

flavin mononucleotide (FMN)

Question 25

can move freely within the lipid bilayer of the membrane and thus can shuttle electrons between other, less mobile carriers.

Answer 25

ubiquinone, also called coenzyme Q (CoQ)

Question 26

– The term “chemiosmotic,” coined by Peter Mitchell, reflects the fact that the production of ATP in oxidative phosphorylation includes both chemical processes (the “chemi” portion of the term) and transport processes across a selectively permeable membrane (the “osmotic” portion of the term)

Answer 26

chemiosmotic coupling

Question 27

the oxidation of pyruvate to acetyl CoA yields

Answer 27

two molecules of NADH

Question 28

The Strategy of Energy Metabolism

Answer 28

catabolism anabolism

Question 29

– the mechanism by which oxidative phosphorylation is accomplished – mechanism of ATP synthesis

Answer 29

chemiosmotic coupling

Question 30

(endergonic) are the pathways by which cells synthesize the diversity of molecules that constitute a living organism

Answer 30

anabolism

Question 31

takes place in the cytosol, and in the presence of oxygen yields 2 molecules of ATP directly plus 2 molecules of NADH per molecule of glucose. The net yield from reoxidation of the 2 NADH molecules is only 4 molecules of ATP, rather than the 6 that would otherwise be expected.

Answer 31

Glycolysis

Question 32

the principal electron carriers of the chain

Answer 32

 flavin mononucleotide (FMN) - which receives two electrons from NADH and passes them to CoQ  coenzyme Q (CoQ) - located in the lipid interior of the membrane, ferries electrons from Complex I to Complex III, which contains cytochrome b  cytochromes b, c, a, and a3

Question 33

consists overall of glycolysis, the citric acid cycle, and the electron transport chain

Answer 33

Respiration

Question 34

(from glyco-, meaning “sugar,” and lysis, meaning “splitting”), the six-carbon glucose molecule is split into two molecules of pyruvate

Answer 34

Glycolysis

Question 35

In many bacteria, fungi, protists, and animal cells, this oxygenless, or anaerobic, process results in the formation of lactate, a three-carbon compound similar in structure to pyruvate.

Answer 35

Lactate Fermentation

Question 36

the universal energy currency in living organisms

Answer 36

ATP

Question 37

 occurs in a series of 10 steps, each catalyzed by a specific enzyme  an anaerobic process that occurs in the cytosol  begins with preparatory phase, which requires an input of energy in the form of ATP (steps 1 and 3)  have two phases: Preparatory phase – Energy investment: 2ATP Payoff phase – Energy yield: 4ATP and 2NADH  Ends with Most of the Energy of the Original Glucose Molecule Still Present in the Two Pyruvate Molecules

Answer 37

Glycolysis

Question 38

Is the Chief Source of Energy in Most Cells

Answer 38

glucose

Question 39

also occurs in the matrix of the mitochondrion, yielding 2 molecules of ATP, 6 of NADH, and 2 of FADH2

Answer 39

Citric acid cycle

Question 40

is involved in the formation of ATP using energy supplied to electrons by the sun. It can also be used to power other transport processes

Answer 40

chemiosmotic power

Question 41

The two-step process by which pyruvate is converted anaerobically to ethanol. In the first step, carbon dioxide is released. In the second, NADH is oxidized and acetaldehyde is reduced

Answer 41

Alcohol Fermentation

Question 42

Completes the Metabolic Breakdown of Glucose to Carbon Dioxide

Answer 42

citric acid cycle

Question 43

Is Achieved by the Chemiosmotic Coupling Mechanism

Answer 43

Oxidative Phosphorylation

Question 44

the yield of the citric acid cycle

Answer 44

2 ATP two molecules of FADH2 six molecules of NADH

Question 45

occurs in the matrix of the mitochondrion, yielding 2 molecules of NADH for each molecule of glucose

Answer 45

Conversion of pyruvate to acetyl CoA

Question 46

uses the energy of protons moving down their gradient to produce ATP

Answer 46

ATP synthase

Question 47

In yeast and most plant cells, however, pyruvate is converted to ethanol (ethyl alcohol) and carbon dioxide.

Answer 47

Alcohol Fermentation

Question 48

protein molecules with an iron-containing porphyrin ring, or heme group, attached

Answer 48

cytochromes

Question 49

Glycolysis (from glucose to pyruvate) can be summarized by the overall equation:

Answer 49

Glucose + 2NAD+ + 2ADP + 2Pi ⎯→ 2 Pyruvate + 2NADH + 2H+ + 2ATP + 2H2O

Question 50

is the cleavage step from which glycolysis derives its name

Answer 50

step 4

Question 51

the formation of ATP by the enzymatic transfer of a phosphate group from a metabolic intermediate to ADP, as occurs in steps 7 and 10

Answer 51

Substrate-level phosphorylation

Question 52

The overall equation for the citric acid cycle is therefore:

Answer 52

Oxaloacetate + Acetyl CoA + 3H2O + ADP + Pi + 3NAD+ + FAD ⎯→ Oxaloacetate + 2CO2 + CoA + ATP + 3NADH + 3H+ + FADH2

Question 53

The most abundant components of the electron transport chain

Answer 53

quinone molecules

Question 54

This enzyme complex consists of two major portions, FO, which is contained within the inner membrane of the mitochondrion, and F1, which extends into the matrix.

Answer 54

ATP synthase

Question 55

reflects the fact that the production of ATP in oxidative phosphorylation includes both chemical processes

Answer 55

chemi

Question 56

transport processes across a selectively permeable membrane

Answer 56

osmotic

Question 57

The two-step process by which pyruvate is converted anaerobically to ethanol.

Answer 57

In the first step, carbon dioxide is released. In the second, NADH is oxidized and acetaldehyde is reduced.

Question 58

alcohol fermentation equation

Answer 58

Glucose + 2ADP + 2Pi ⎯→ 2 Ethanol + 2CO2 + 2ATP + 2H2O

Question 59

lactate fermentation equation

Answer 59

Glucose + 2ADP + 2Pi ⎯→ 2 Lactate + 2ATP + 2H2O

Question 60

oxidation

Answer 60

loss of electron

Question 61

reduction

Answer 61

gain of electron

Question 62

process for a fat to convert to acetyl CoA and enter the citric acid cycle, the triglyceride molecule is first hydrolyzed to glycerol and three fatty acids. Then, beginning at the carboxyl end of the fatty acids, two-carbon acetyl groups are successively removed as acetyl CoA.

Answer 62

Beta oxidation

Question 63

protein complex that is not a part of the transfer of electrons from NADH to O2

Answer 63

complex II