Chapter 8

Question 1

Metabolism

Answer 1

Sum of all chemical reactions occurring in an organism

Question 2

Metabolic pathway

Answer 2

Begins with a specific molecule and ends with a product. Each step is catalyze by a specific enzyme

Question 3

Catabolic pathways

Answer 3

Release energy. Break down complex molecules into simpler compounds

Question 4

Anabolic pathways

Answer 4

Consume energy to build complex molecules from simpler ones. Ex: synthesis of protein from amino acids

Question 5

Energy

Answer 5

The capacity to cause change. Exists in various forms, some of which can perform work

Question 6

Kinetic energy

Answer 6

Energy associated with motion

Question 7

Potential energy

Answer 7

Energy that matter possesses because of its location or structure

Question 8

First law of thermodynamics

Answer 8

Energy can be transferred and transformed but it cannot be created or destroyed. Sunlight is converted into chemical energy by photosynthesis

Question 9

During every energy transfer/transformation…

Answer 9

Some energy is unusable and is often lost as heat

Question 10

Second law of thermodynamics

Answer 10

Every energy transfer/transformation increases the entropy of the universe

Question 11

Entropy

Answer 11

A measure of molecular disorder or randomness

Question 12

Spontaneous processes

Answer 12

Occur without energy input and can happen quickly or slowly. For a process to occur without energy input, it must increase the entropy of the universe

Question 13

Disorder

Answer 13

Happens spontaneously

Question 14

Organization

Answer 14

Requires energy

Question 15

Order and disorder

Answer 15

Cells create ordered structures from less ordered materials. Organisms also replace ordered forms of matter and energy with less ordered forms

Question 16

Free energy

Answer 16

The energy available to work. The symbol G

Question 17

Enthalpy

Answer 17

Energy contained in a molecules chemical bonds

Question 18

Delta G is positive

Answer 18

When products contain more free energy than reactants

Question 19

Delta G is negative

Answer 19

When reactants contain more free energy than products

Question 20

Endergonic reaction

Answer 20

A reaction requiring an input of energy (not spontaneous) Delta G is positive

Question 21

Exergonic reaction

Answer 21

A reaction that releases free energy (spontaneous). Delta G is negative

Question 22

ATP is composed of

Answer 22

Ribose (a sugar), adenine (a nitrogenous base), and three phosphate groups

Question 23

Hydrolysis of ATP

Answer 23

ATP is turned into ADP by hydrolysis.

Question 24

Activation energy

Answer 24

Extra energy needed to get a reaction started.

Question 25

Catalysts

Answer 25

Substances that lower activation energy of a reaction. Cannot make an endergonic reaction spontaneous.

Question 26

Enzyme

Answer 26

Biological catalyst. Most enzymes are proteins

Question 27

Substrate

Answer 27

The reactant that an enzyme acts on is called the enzymes substrate

Question 28

Enzyme-substrate complex

Answer 28

The enzyme binds to its substrate, forming an enzyme-substrate complex

Question 29

Active site

Answer 29

The region on the enzyme where the substrate binds

Question 30

Induced fit

Answer 30

Induced fit of a substrate brings chemical groups of the active sit into positions that enhance their ability to catalyze the reaction

Question 31

Cofactors

Answer 31

Usually metal ions, found in the active site participating in catalysts (Zn, Mn, Mo)

Question 32

Coenzymes

Answer 32

Organic molecule cofactors which include vitamins

Question 33

Inhibitor

Answer 33

Substance that binds to enzyme and decreases it’s activity

Question 34

Competitive inhibitors

Answer 34

Bind to the active site of an enzyme, competing with the substrate

Question 35

Noncompetitive inhibitors

Answer 35

Bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective

Question 36

Allosteric enzymes

Answer 36

Exist in either an active or inactive state

Question 37

Allosteric site

Answer 37

Allosteric enzymes possess an allosteric site where molecules other than the substrate bind

Question 38

Allosteric inhibitors

Answer 38

Bind to the allosteric site to inactivate the enzyme

Question 39

Allosteric activators

Answer 39

Bind to the allosteric site to activate the enzyme

Question 40

Biochemical pathways

Answer 40

A series of reactions in which the product of one reaction becomes the substrate for the next reaction

Question 41

Feedback inhibition

Answer 41

The end product of a metabolic pathway shuts down the pathway

Question 42

Feedback inhibition prevents a cell

Answer 42

From wasting chemical resources by synthesizing more product than is needed