Exam 3: Metabolism and Enzymes

Question 1

metabolism

Answer 1

the chemical reactions that occur in living cells through various pathways that utilize enzymes

Question 2

catabolism

Answer 2

a specific type of metabolism that breaks down molecules to release energy

Question 3

anabolism

Answer 3

a specific type of metabolism that uses energy to construct molecules for use in the cell

Question 4

potential energy

Answer 4

the energy in a system due to the position or arrangement of the system

Question 5

kinetic energy

Answer 5

the energy in a system due to motion

Question 6

Gibb’s free energy

Answer 6

the amount of available potential energy in a system, or the amount of work that can be extracted from the system

Question 7

enthalpy

Answer 7

the total energy of a system

Question 8

entropy

Answer 8

the disorder of a system; systems tend toward increased entropy

Question 9

spontaneous process

Answer 9

a reaction that will occur without the addition of external energy; the rate of the reaction is not related to its spontaneity; includes exergonic reactions

Question 10

nonspontaneous process

Answer 10

a reaction that needs additional energy to proceed; includes endergonic reactions

Question 11

exergonic reaction

Answer 11

a reaction in which energy flows from the system to the environment; exergonic reactions are spontaneous

Question 12

endergonic reaction

Answer 12

a reaction in which energy flows from the environment to the system; endergonic reactions are nonspontaneous

Question 13

enzyme

Answer 13

proteins that increase the rate of reactions, usually by lowering the activation energy

Question 14

activation energy

Answer 14

the amount of energy needed in order to catalyze a chemical reaction

Question 15

substrate

Answer 15

molecule that binds to the active site of an enzyme and forms a substrate-enzyme complex

Question 16

product

Answer 16

the molecule that is released from an enzyme after a reaction is catalyzed

Question 17

active site

Answer 17

the part of an enzyme where a substrate binds; recognizes substrates specific to the enzyme

Question 18

allosteric site

Answer 18

a site on the enzyme (not the active site) to which molecules can bind

Question 19

competitive inhibitor

Answer 19

inhibits the function of an enzyme by binding to the active site and preventing the formation of the enzyme-substrate complex

Question 20

noncompetitive inhibitor

Answer 20

inhibits the function of an enzyme by preventing the enzyme-substrate complex from completing the reaction and producing a product

Question 21

allosteric activator

Answer 21

a molecule that binds to an allosteric site and increases the affinity of the active site for the substrate

Question 22

allosteric inhibitor

Answer 22

a molecule that binds to an allosteric site and decreases the affinity of the active site for the substrate

Question 23

feedback inhibition

Answer 23

inhibition that occurs when a product of the enzymatic reaction binds to and inhibits the same enzyme

Question 24

cofactors

Answer 24

an organic or inorganic molecule that binds to a protein and facilitates its biological function

Question 25

coenzymes

Answer 25

an organic cofactor that binds to enzymes, often at the active site, to facilitate enzymatic activity