Ch. 6 - An Introduction to Energy, Enzymes, and Metabolism

Question 1

ability to cause change or do work

Answer 1

Energy

Question 2

energy associated with movement

Answer 2

Kinetic Energy

Question 3

the energy that a substance or object possesses due to its structure or location

Answer 3

Potential Energy

Question 4

the energy that is stored in atoms and in the bonds between atoms

Answer 4

Chemical Potential Energy

Question 5

a form of electromagnetic radiation that is visible to the eye; packaged in photons.

Answer 5

Light Energy

Question 6

the transfer of kinetic energy from one object to another or from an energy source to an object; viewed as kinetic energy that can be transferred due to a difference in temperature between two objects or locations

Answer 6

Heat Energy

Question 7

the energy possessed by an object due to its motion or its position relative to other objects

Answer 7

Mechanical Energy

Question 8

the movement of charge or the separation of charges can provide energy; a difference in ion concentration across a membrane creates an electrochemical gradient, which is a source of potential energy

Answer 8

Electrical/Ion Gradient Energy

Question 9

energy cannot be created or destroyed; energy can be transferred and can be transformed from one type to another

Answer 9

First Law of Thermodynamics

Question 10

any energy transfer or transformation from one form to another increases the degree of disorder of a system

Answer 10

Second Law of Thermodynamics

Question 11

measure of randomness of molecules in a system

Answer 11

Entropy

Question 12

total energy of a system

Answer 12

Enthalpy

Question 13

usable energy - the amount of energy that is available and can be used to promote change or do work

Answer 13

Free Energy

Question 14

free energy is released during product formation; spontaneous

Answer 14

Exergonic

Question 15

positive free-energy change requiring the addition of free energy; not spontaneous

Answer 15

Endergonic

Question 16

a phosphate is directly transferred from ATP to glucose

Answer 16

Phosphorylation

Question 17

an agent that speeds up the rate of a chemical reaction without being permanently changed or consumed by it

Answer 17

Catalyst

Question 18

an initial input of energy needed to overcome the repulsion of the electrons in the outer shells of atoms repelling each other

Answer 18

Activation Energy

Question 19

when the original bonds have stretched to their limit; the chemical reaction can readily proceed to the formation of products

Answer 19

Transition State

Question 20

location in an enzyme where the chemical reaction takes place

Answer 20

Active Site

Question 21

reactant molecules that bind to an enzyme at the active site and participate in the chemical reaction

Answer 21

Substrates

Question 22

the binding between enzymes and substrates

Answer 22

Enzyme-Substrate Complex

Question 23

conformational changes cause the substrates to bind more tightly to the enzyme

Answer 23

Induced Fit

Question 24

maximal rate when the enzyme is saturated with substrate

Answer 24

Vmax

Question 25

substrate concentration at which the velocity is half its maximal value

Answer 25

Km

Question 26

molecules that bind non-covalently to the active site of an enzyme and inhibit the ability of the substrate to bind

Answer 26

Competitive Inhibitors

Question 27

decreasing the Vmax for the reaction without affecting the Km; binds non-covalently to an enzyme at a location outside the active site and inhibits the enzyme’s function

Answer 27

Noncompetitive Inhibitors

Question 28

usually bind covalently to an enzyme to inhibit its function

Answer 28

Irreversible Inhibitors

Question 29

small molecules that are permanently attached to the surface of an enzyme and aid in enzyme function

Answer 29

Prosthetic Groups

Question 30

temporarily bind to the surface of an enzyme and promote a chemical reaction; ex. inorganic ions

Answer 30

Cofactors

Question 31

organic molecules that temporarily bind to an enzyme and participate in the chemical reaction that the enzyme catalyzes, but are left uncharged when the reaction is completed

Answer 31

Coenzymes

Question 32

chemical reactions are coordinated with each other and often occur in a series of steps with each step catalyzed by a specific enzyme

Answer 32

Metabolic Pathway

Question 33

breakdown of larger molecules into smaller ones; often exergonic

Answer 33

Catabolic Reaction

Question 34

involves the synthesis of larger molecules from smaller precursor molecules; usually endergonic

Answer 34

Anabolic Reaction

Question 35

directly used to drive endergonic reactions in cells; ex. molecules like ATP; store energy from when cells break covalent bonds in organic molecules

Answer 35

Energy Intermediates

Question 36

occurs when an enzyme directly transfers a phosphate from an organic molecule to ADP, thereby making ATP

Answer 36

Substrate-Level Phosphorylation

Question 37

energy stored in an ion electrochemical gradient is used to make ATP from ADP & P

Answer 37

Chemiosmosis

Question 38

the removal of one or more electrons from an atom or molecule

Answer 38

Oxidation

Question 39

addition of one or more electrons to an atom or molecule

Answer 39

Reduction

Question 40

when an atom or molecule is oxidized the electron that is removed must be transferred to another atom or molecule, which becomes reduced

Answer 40

Redox Reaction

Question 41

slowest step of the metabolic pathway; if this step is inhibited or enhanced, such changes will have the greatest influence on the formation of the final product of the metabolic pathway

Answer 41

Rate-Limiting Step

Question 42

time it takes for 50% of a specific type of molecule in a cell to be broken down and recycled

Answer 42

Half-life

Question 43

enzymes that cleave the bonds between adjacent amino acids

Answer 43

Proteases

Question 44

primary pathway for protein degradation in archaea and eukaryotic cells occurs via a protein complex; 4 stacked rings with 7 protein subunits each

Answer 44

Proteasome

Question 45

cellular material becomes enclosed in a double membrane

Answer 45

Autophagy

Question 46

when a double membrane is formed from a tubule that elongates and eventually wraps around the organelle

Answer 46

Autophagosome