CH 8, 9, 10

Question 1

Endergonic

Answer 1

“energy inward”
- absorbs free energy from its surroundings
- reactions non-spontaneous

Question 2

Exergonic

Answer 2

“energy outward”
- a net release of free energy
- the products have less free energy than the reactants
- reactions are spontaneous

Question 2

enzyme

Answer 2

a macromolecule that acts as a catalyst
- a chemical agent that speeds up a reaction without being consumed by the reaction

Question 3

How does activation energy affect an enzyme’s catalyst activity

Question 4

How enzymes speed up reactions

Answer 4

• Heat can increase the rate of reaction
  high temperatures denature proteins and kill cells

Question 5

Catalysis

Answer 5

the process by which a catalyst selectively speeds up a reaction without itself being consumed

Question 6

Substrate

Answer 6

the reactant on which an enzyme works

Question 7

Enzyme-substrate complex

Answer 7

when an enzyme binds to its substrate

Question 8

enzyme equation process:

Answer 8

enzyme + substrate = enzyme-substrate complex = enzyme + products

Question 9

Effects of Temperature

Answer 9

• rate of an enzymatic reaction increases with increasing temperature.
• Above that temperature, the speed of the enzymatic reaction drops sharply = the protein molecule will denature.
• each enzyme has an optimal temperature at which its reaction rate is greatest.

Question 10

Effects of pH

Answer 10

enzyme has a pH at which it is active.
- optimal pH values: ranges pH 6-8

Question 11

2 types of Enzyme inhibitors

Answer 11

Competetive inhibition
noncompetitive inhibition

Question 12

Competitive inhibitor

Answer 12

• a competitive inhibitor mimics the substrate, competing for the active site

Question 13

Noncompetitive inhibition

Answer 13

• binds to the enzyme away from the active site, altering the shape of the enzyme so that even though the substrate can still bind, the active site functions much less effectively
• do not directly compete with the substrate to bind to the enzyme at the active site

Question 14

activation energy

Answer 14

the energy necessary to break the bonds of the reactants

Question 15

fermentation

Answer 15

• catabolic process
  a partial degradation of sugars/ other organic fuel that occurs without the use of oxygen

Question 16

aerobic respiration

Answer 16

• a catabolic process
• oxygen is used as a reactant
• cells of most eukaryotic and many prokaryotic organisms can carry out aerobic respiration

Question 17

anaerobic respiration

Answer 17

• using substances other than oxygen as reactants in a similar process that harvests chemical energy whithout oxygen