Chapter 14 - Vocab

Question 1

metabolism

Answer 1

the total of all degradative and biosynthetic cellular reactions

Question 2

catabolism

Answer 2

the degradative metabolic reactions in which nutrients and cell constituents are broken down for energy and raw materials

Question 3

anabolism

Answer 3

the reactions by which biomolecules are synthesized from simpler components

Question 4

nutrition

Answer 4

the intake and utilization of food as a source of raw materials and free energy

Question 5

autotroph

Answer 5

an organism that can synthesize all its cellular components from simple molecules using the energy obtained from sunlight (photoautotroph) or from the oxidation of inorganic compounds (chemolithotroph)

Question 6

chemolithotroph

Answer 6

an autotrophic organism that obtains energy from the oxidation of inorganic compounds

Question 7

photoautotroph

Answer 7

an autotrophic organism that obtains energy from sunlight

Question 8

heterotroph

Answer 8

an organism that obtains free energy from the oxidation of organic compounds produced by other organisms

Question 9

anaerobe

Answer 9

an organism that does not us O2 as an oxidizing agent for nutrient breakdown; an obligate anaerobe cannot grow in the presence of 02, whereas a facultative anaerobe can grow in the presence or absence of O2

Question 10

aerobe

Answer 10

an organism that uses O2 as an oxidizing agent for nutrient breakdown

Question 11

macronutrient

Answer 11

a nutrient that is required in relatively large amounts, such as proteins, carbohydrates, and fats

Question 12

micronutrient

Answer 12

a nutrient that is required in relatively small amounts, such as vitamins and minerals

Question 13

vitamin

Answer 13

a metabolically required organic substance that cannot be synthesized by an animal and must therefore be obtained from its diet

Question 14

mineral

Answer 14

an inorganic substance required for metabolic activity, including sodium, potassium, chloride, and calcium; minerals such as iron, copper, and zinc, which are required in small amounts, are known as trace elements

Question 15

metabolite

Answer 15

a reactant, intermediate, or product of a metabolic reaction

Question 16

oxidation

Answer 16

the loss of electrons; oxidation of a substance is accompanied by the reduction of another substance

Question 17

reduction

Answer 17

the gain of electrons; reduction of a substance is accompanied by the oxidation of another substance

Question 18

isozyme

Answer 18

enzymes that catalyze the same reaction but are encoded by different genes (aka “isoforms”)

Question 19

near-equilibrium reaction

Answer 19

a reactions whose change in free energy value is close to zero, so that it can operate in either direction depending on the substrate and product concentrations

Question 20

flux

Answer 20

(1) the rate of flow of metabolites through a metabolic pathway
(2) the rate of transport per unit area

Question 21

substrate cycle

Answer 21

two opposing sets of metabolic reaction that, in many cases, function together to hydrolyze ATP, but provide a control point for regulating metabolic flux (aka “futile cycle”)

Question 22

“high-energy” intermediate

Answer 22

a substance whose degradation is highly exergonic (yield as much free energy as is required to synthesize ATP from ADP + Pi >=30.5 kJ/mol under standard biochemical conditions) (aka “energy-rich” compound)

Question 23

orthophosphate cleavage

Answer 23

the hydrolysis of ATP that yields ADP + Pi

Question 24

pyrophosphate cleavage

Answer 24

the hydrolysis of ATP that yields AMP + PPi

Question 25

substrate-level phosphorylation

Answer 25

the direct transfer of a phosphoryl group to ADP to generate ATP

Question 26

oxidative phosphorylation

Answer 26

the process by which the free energy obtained from the oxidation of metabolic fuels is used to generate ATP from ADP + Pi

Question 27

photophosphorylation

Answer 27

the synthesis of ATP from ADP + Pi coupled to the dissipation of a proton gradient that has been generated through light-driven electron transport

Question 28

kinase

Answer 28

an enzyme that transfers a phosphoryl group between ATP and another molecule

Question 29

phosphagen

Answer 29

a phosphoguanidine whose phosphoryl group-transfer potential is greater than that of ATP; these compounds can therefore phosphorylate ADP to generate ATP

Question 30

reducing agent

Answer 30

a substance that can donate electrons, thereby reducing another substance and becoming oxidized

Question 31

oxidizing agent

Answer 31

a substance that can accept electrons, thereby oxidizing another substance and becoming reduced

Question 32

half-reaction

Answer 32

the single oxidation or reduction process, involving an electron donor and its conjugate electron acceptor, that occurs in electrical cells but requires direct contact with another such reaction to form a complete oxidation-reduction reaction

Question 33

redox couple

Answer 33

an electron donor and acceptor that from a half-reaction (aka “conjugate redox pair”)

Question 34

conjugate redox pair

Answer 34

and electron donor and acceptor that form a half-reaction (aka “redox couple”)

Question 35

electrochemical cell

Answer 35

a device in which two half-reactions occur in separate compartments linked by a wire for transporting electrons and a salt bridge for maintaining electrical neutrality; the simultaneous activity of the half-reactions forms a complete oxidation-reduction reaction

Question 36

reduction potential

Answer 36

a measure of the tendency of a substrate to gain electrons

Question 37

Nernst equation

Answer 37

an expression of the relationship between reduction potential difference and the concentrations of the electron donors and acceptors

Question 38

Faraday

Answer 38

the electrical charge of one mole of electrons (96,485 C/mol)