How Cells Obtain Energy 4.1 Energy and Metabolism

Question 1

activation energy

Answer 1

the amount of initial energy necessary for reactions to occur

Question 2

active site

Answer 2

a specific region on the enzyme where the substrate binds

Question 3

allosteric inhibition

Answer 3

the mechanism for inhibiting enzyme action in which a regulatory molecule binds to a second site (not the active site) and initiates a conformation change in the active site, preventing binding with the substrate

Question 4

anabolic

Answer 4

describes the pathway that requires a net energy input to synthesize complex molecules from simpler ones

Question 5

bioenergetics

Answer 5

the concept of energy flow through living systems

Question 6

catabolic

Answer 6

describes the pathway in which complex molecules are broken down into simpler ones, yielding energy as an additional product of the reaction

Question 7

competitive inhibition

Answer 7

a general mechanism of enzyme activity regulation in which a molecule other than the enzyme’s substrate is able to bind the active site and prevent the substrate itself from binding, thus inhibiting the overall rate of reaction for the enzyme

Question 8

endergonic

Answer 8

describes a chemical reaction that results in products that store more chemical potential energy than the reactants

Question 9

enzyme

Answer 9

a molecule that catalyzes a biochemical reaction

Question 10

exergonic

Answer 10

describes a chemical reaction that results in products with less chemical potential energy than the reactants, plus the release of free energy

Question 11

feedback inhibition

Answer 11

a mechanism of enzyme activity regulation in which the product of a reaction or the final product of a series of sequential reactions inhibits an enzyme for an earlier step in the reaction series

Question 12

heat energy

Answer 12

the energy transferred from one system to another that is not work

Question 13

kinetic energy

Answer 13

the type of energy associated with objects in motion

Question 14

metabolism

Answer 14

all the chemical reactions that take place inside cells, including those that use energy and those that release energy

Question 15

noncompetitive inhibition

Answer 15

a general mechanism of enzyme activity regulation in which a regulatory molecule binds to a site other than the active site and prevents the active site from binding the substrate; thus, the inhibitor molecule does not compete with the substrate for the active site; allosteric inhibition is a form of noncompetitive inhibition

Question 16

potential energy

Answer 16

the type of energy that refers to the potential to do work

Question 17

substrate

Answer 17

a molecule on which the enzyme acts

Question 18

thermodynamics

Answer 18

the science of the relationships between heat, energy, and work