Chapter 7 Vocabulary

Question 1

Acetyl coenzyme A; the entry compound for citric acid cycle in cellular respiration, formed from a two-carbon fragment of pyruvate attached to a coenzyme.

Answer 1

Acetyl CoA

Question 2

A catabolic pathway for organic molecules, using oxygen as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukarytoic cells and many prokaryotic organisms.

Answer 2

Aerobic Respiration

Question 3

Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD and releasing carbon dioxide.

Answer 3

Alcohol fermentation

Question 4

An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokarytoic cells.

Answer 4

Cytochrome

Question 5

A complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membranes of eukarytotic cells and in the plasma membranes of prokaryotes.

Answer 5

ATP synthase

Question 6

`The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecues and use an electron transport chain for the production of ATP.

Answer 6

Cellular respiration

Question 7

An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis.

Answer 7

Chemiosmosis

Question 8

A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryots; together with pyruvate oxidation, the second major stage in cellular respiration.

Answer 8

Citric acid cycle

Question 9

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP.

Answer 9

Electron transport chain

Question 10

An organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present.

Answer 10

Facultative anarobe

Question 11

A catabolic process that makes a limited amount of ATP from glucose (or other organic molecules) without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

Answer 11

Fermentation

Question 12

A series of reactions that ultimately splits glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.

Answer 12

Glycolysis

Question 13

Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD with no release of carbon dioxide.

Answer 13

Lactic acid fermentation

Question 14

Nicotinamide adenine dinucleotide, a coenzyme that cycles easily between oxidized (NAD) and reduced (NADH) states, thus acting as an electron carrier.

Answer 14

NAD

Question 15

The complete or partial loss of electrons from a substance involved in a redox reaction.

Answer 15

Oxidation

Question 16

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

Answer 16

Oxidative phosphorylation

Question 17

An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.

Answer 17

Obligate anarobe

Question 18

The potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen ions (H+) across a biological membrane during chemiosmosis.

Answer 18

Proton-motive force

Question 19

A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another; short for reduction-oxidation reaction.

Answer 19

Redox reaction

Question 20

The complete or partial addition of electrons to a substance involved in a redox reaction.

Answer 20

Reduction

Question 21

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

Answer 21

Substrate-level phosphorylation