Enzymes

Question 1

What is one of the fastest enzymes?

Answer 1

Carbon anhydrase

Question 2

Enzymes are _____ specific

Answer 2

highly

Question 3

Does an enzyme determine if a rxn occurs or not?

Answer 3

No, free energy does

Question 4

For a spont. rxn. to occur G must be

Answer 4

Negative

Question 5

At equilibrium G is

Answer 5

0

Question 6

What is free energy independent of?

Answer 6

Path of formation

Question 7

Does G tell us about the rate of the reaction?

Answer 7

No

Question 8

What are the 2 standard cond. for standard free energy change

Answer 8

reactants and products have concentrations of 1M, 1atm for gas
Temperature is 298K

Question 9

What is the formula for delta G?

Answer 9

deltaG=standardG + RTln[products]/[reactants]

Question 10

What is G at equilibrium?

Answer 10

0

Question 11

what is the G formula at equilibrium?

Answer 11

StandardG’=-RTlnKeq

Question 12

G must be _____ to be energetically favourable (spont)

Answer 12

Negative

Question 13

Are spontaneous rxns instantaneous?

Answer 13

Enzymes

Question 14

Enzymes makes spont rxns that are ______ favourable

Answer 14

kinetically

Question 15

What is the symbol for activation energy?

Answer 15

=|

Question 16

Enzymes decrease the ____ to overcome the

Answer 16

activation energy, activation energy barrier

Question 17

What are the x and y axis of a typical enzyme lookin graph?

Answer 17

X=rxn progress

Y=free energy

Question 18

How do enzymes lower the Ea

Answer 18

Stabilize the transition state

Question 19

What is the symbol for transition state?

Answer 19

X=|

Question 20

Do enzymes alter the rxn rate? The equilibrium?

Answer 20

Yes, no

Question 21

Where do the residues of the active site come from?

Answer 21

Different positions in amino aa seq

Question 22

an active site forms ______ with substrates

Answer 22

multiple weak interactions

Question 23

specificity of substrate binding depends on

Answer 23

present arrangement of active site residues

Question 24

What are the 5 features of the enzyme active site?

Answer 24

1. Residues forming the active site come from different positions in aa seq
2. small vol of total protein
3. Unique microenvironment
4. forms multiple weak interactions with substrates
5. specificity depends on present arrangement of active site residue

Question 25

Cofactors

Answer 25

non-protein compounds that bind to proteins to provide biological activity

Question 26

Apoenzyme

Answer 26

wihtout cofactor

Question 27

Holoenzyme

Answer 27

with cofactor

Question 28

Prosthetic group

Answer 28

non-protein molecule tightly bound to enzyme

Question 29

Cosubstrate

Answer 29

non-protein molecule that can dissociate from enzyme

Question 30

What are coenzymes derived from?

Answer 30

vitamins

Question 31

How is free energy released?

Answer 31

When many weak interactions occur b/w the enzyme and transition state

Question 32

When does max binding energy occur?

Answer 32

during the transition state

Question 33

Why do we use Gibbs free energy?

Answer 33

Understand whther a rxn is spont and to understand energetics

Question 34

What does the active site do

Answer 34

stabilizes the transition state

Question 35

Binding energy provides..

Answer 35

most of the energy used to lower the activation energy