Chapter 6 - Making Life Work: Capturing And Using Energy

Question 1

The energy of motion

Answer 1

Kinetic Energy

Question 2

Stored energy that is released by a change in an object’s structure or position

Answer 2

Potential Energy

Question 3

The law of conservation of energy: Energy can neither be created nor destroyed- it can only be transformed from one form into another

Answer 3

First Law of Thermodynamics

Question 4

The principle that the transformation of energy is associated with an increase in the degree of disorder in the universe

Answer 4

Second Law of Thermodynamics

Question 5

The degree of disorder in a system

Answer 5

Entropy (S)

Question 6

The amount of energy available to do work

Answer 6

Gibbs Free Energy (G)

Question 7

Describes reactions with a negative 🔼G that release energy and proceed spontaneously

Answer 7

Exergonic

Question 8

Describes reactions with a positive 🔼G that are not spontaneous and so require an input on energy

Answer 8

Endergonic

Question 9

The total amount of energy in a system

Answer 9

Enthalpy (H)

Question 10

Temperature measure on the Kelvin scale

Answer 10

Absolute Temperature (T)

Question 11

The driving of a non-spontaneous reaction by a spontaneous reaction

Answer 11

Energetic coupling

Question 12

A protein that functions as a catalyst to accelerate the rate of a chemical reaction; enzymes are critical in determining which chemical reactions take place in a cell

Answer 12

Enzyme

Question 13

The brief time in a chemical reaction in which chemical bonds in the reactants are broken and new bonds in the product are formed

Answer 13

Transition State

Question 14

The energy input necessary to reach the transition state

Answer 14

Activation Energy (EA)

Question 15

A molecule acted upon by an enzyme

Answer 15

Substrate (S)

Question 16

The portion of the enzyme that binds substrate and concerts it to product

Answer 16

Active Site

Question 17

Any one of a class of inhibitors that usually forms covalent bonds with enzymes and irreversibly inactivated them

Answer 17

Irreversible Inhibitors

Question 18

Any molecule in the class of inhibitors that form weak bonds with enzymes and easily dissociate from them

Answer 18

Reversible Inhibitors

Question 19

A reversible inhibitor that reduces the affinity of the substrate for the active site of an enzyme, but can be overcome by excess substrate so the maximum velocity of the reaction is not changed. Competitive inhibitors usually have a structure similar to that of the substrate and therefore bind to the active site of the enzyme

Answer 19

Competitive Inhibitor

Question 20

A reversible inhibitor that reduces the maximum velocity of the reaction, but does not affect the affinity of the substrate for the active site of the enzyme. It usually has a structure very different from that of the substrate and binds to the enzyme at a site different from the active site

Answer 20

Non-competitive Inhibitor

Question 21

Describes the effect in which the final product of a biochemical pathway inhibits the first step; the process in which a stimulus acts on a sensor that communicates with an effective, producing a response that opposes the initial stimulus. Negative feedback is used to maintain steady conditions, or homeostasis

Answer 21

Negative Feedback

Question 22

An enzyme whose activity is affected by binding a molecule at a site other than the active site. Typically, also steric enzymes change their shape on binding an activator or inhibitor

Answer 22

Allosteric Enzyme

Question 23

A substance that associates with an enzyme and plays a key role in its function

Answer 23

Cofactors

Question 24

The molecule that provides energy in a form that all cells can readily use to perform the work of the cell. ATP is the universal energy currency for all cells.

Answer 24

Adenosine triphosphate (ATP)