Enzymes

Question 1

Catalyst

Answer 1

speed up chemical reactions, but aren’t part of the substrate or product

Question 2

Favorable Reactions

Answer 2

exergonic (-G), can move right, slow, need input to speed up

Question 3

Non Favorable Reactions

Answer 3

don’t move (G=0) or endergonic (+G) (move left

Question 4

Transition State

Answer 4

middle step for chemical reactions, needs more energy than reactants, makes stable complex molecules

Question 5

Activation Energy

Answer 5

energy needed to get to transition state

Question 6

Low Barrier (Activation Barrier)

Answer 6

fast reaction, most reactants have enough energy

Question 7

High Barrier (Activation Barrier)

Answer 7

slow reaction, few reactants have enough energy

Question 8

How to speed up reactions in favorable reactions:

Answer 8

increase temp of reactants, lower activation barrier

Question 9

Enzyme

Answer 9

catalysts in biological systems, either protein or ribosome, lower activation energy barrier

Question 10

Enzyme-Substrate Complex

Answer 10

where substrate and enzyme interact

Question 11

Active Site

Answer 11

cavity structure in enzyme where substrate binds, very specific shape

Question 12

Induced Fit

Answer 12

substrates interact to see if they can fit perfectly in the enzyme, physical change in enzyme if correct

Question 13

Covalent Modification

Answer 13

covalently changed shape and function of enzyme

Question 14

Phosphorylation

Answer 14

add a phosphate group to protein, changes 3D structure

Question 15

Dephosphorylation

Answer 15

remove phosphate group from protein, changes 3D structure

Question 16

Proteolytic Cleavage

Answer 16

inactive enzyme becomes active, removes amino acids from protein via peptidases

Question 17

Saturation

Answer 17

max load of substrates for available enzymes, can’t keep reacting

Question 18

Effector Molecules

Answer 18

regulate enzyme activity by binding to them

Question 19

Activators

Answer 19

increase rate of reaction

Question 20

Inhibitors

Answer 20

decrease rate of reaction

Question 21

Irreversible Inhibitors

Answer 21

covalently bond to enzyme at active site permanently, used to harm other organisms

Question 22

Reversible Inhibitors

Answer 22

non covalently bond to enzyme, falls off after time, used in body cells to regulate enzymes

Question 23

Competitive Inhibitors

Answer 23

have same shape as substrate, bind to active site to block substrate, reversible

Question 24

Noncompetitive Inhibitors

Answer 24

bind away from active site, changes enzyme structure, reversible

Question 25

Allosteric Effectors

Answer 25

keeps enzyme in one shape (on/off) by binding to them, saves energy in pathways

Question 26

Allosteric Activator

Answer 26

turns enzyme on, in functional shape (able to bind substrate)

Question 27

Allosteric Inhibitor

Answer 27

turns enzyme off, in nonfunctional shape (can’t bind substrate)

Question 28

Feedback Inhibition

Answer 28

buildup of enzyme products inhibits initial enzyme reaction until the product is needed again