Ch 06: Metabolism

Question 1

activation energy

Answer 1

energy necessary for reactions to occur

Question 2

active site

Answer 2

enzyme’s specific region to which the substrate binds

Question 3

allosteric inhibition

Answer 3

inhibition by a binding event at a site different from the active site, which
1. induces a conformational change and
2. reduces the enzyme’s affinity for its substrate

Question 4

anabolic
(also, anabolism)

Answer 4

pathways that require an energy input to synthesize complex molecules from simpler ones

Question 5

adenosine triphosphate
(ATP)

Answer 5

the cell’s energy currency

Question 6

bioenergetics

Answer 6

study of energy flowing through living systems

Question 7

catabolic
(also, catabolism)

Answer 7

pathways in which complex molecules break down into simpler ones

Question 8

chemical energy

Answer 8

potential energy in chemical bonds that releases when those bonds are broken

Question 9

coenzyme

Answer 9

small organic molecule, such as a vitamin or its derivative, which is required to enhance an enzyme’s activity

Question 10

cofactor

Answer 10

inorganic ion, such as iron and magnesium ions, required for optimal enzyme activity regulation

Question 11

competitive inhibition

Answer 11

type of inhibition in which the inhibitor competes with the substrate molecule by binding to the enzyme’s active site

Question 12

denature

Answer 12

process that changes a substance’s natural properties

Question 13

endergonic

Answer 13

describes chemical reactions that require energy input

Question 14

energy coupling

Answer 14

process during which energy released by one reaction is used to drive another reaction

energy released by one reaction drives another

Question 15

enthalpy

Answer 15

a system’s total energy

Question 16

entropy (S)

Answer 16

measure of randomness or disorder within a system

Question 17

exergonic

Answer 17

describes chemical reactions that release free energy

Question 18

feedback inhibition

Answer 18

a cellular control mechanism that regulates metabolic pathways by stopping the production of an end product when it reaches a certain concentration

• The end product of a metabolic pathway binds to an enzyme at the beginning of the pathway, stopping the pathway and preventing further production of the end product

Question 19

free energy (G)

Answer 19

Gibbs free energy is the usable energy, or energy that is available to do work

Question 20

heat

Answer 20

energy transferred from one system to another that is not work (energy of the molecules’ motion or particles)

Question 21

heat energy

Answer 21

total bond energy of reactants or products in a chemical reaction

Question 22

induced fit

Answer 22

dynamic fit between the enzyme and its substrate, in which both components modify their structures to allow for ideal binding

a mild shift in shape at the active site that maximizes the catalysis

Question 23

kinetic energy

Answer 23

energy type that takes place with objects or particles in motion

Question 24

metabolism

Answer 24

all the chemical reactions that take place inside cells, including anabolism and catabolism

Question 25

phosphoanhydride bond

Answer 25

bond that connects phosphates in an ATP molecule

Question 26

potential energy

Answer 26

energy type that has the potential to do work; stored energy

Question 27

substrate

Answer 27

molecule on which the enzyme acts

Question 28

thermodynamics

Answer 28

study of energy and energy transfer involving physical matter

Question 29

transition state

Answer 29

high-energy, unstable state occurring during a chemical reaction

(an intermediate form between the substrate and the product)