Test 3: Ch. 8 Metabolism

Question 1

BE ABLE TO DRAW OUT THE ATP HYDROLYSIS

Answer 1

WHAT HAPPENS?!?!?

Question 2

Things about exergonic reactions, also what is an example of Exergonic Reactions?

Answer 2

1) Example: ATP hydrolysis
2) Energy used to drive endergonic reactions
3) -change in G = free energy (energy available to do work)
4) spontaneous reaction (not necessary explosive)

Question 3

What generally happens in exergonic reactions?

Answer 3

energy is releasing

Question 4

What does Endergonic Reaction require?

Answer 4

Energy

Question 5

Tell me two things about Endergonic Reaction?

Answer 5

1) + change in G

2) non-spontaneous

Question 6

Enzymes: Catalyst. Tell me two things.

Answer 6

1) decrease activation energy needed for reaction (speeds up)
2) recycled

Question 7

Name some enzymes:

Answer 7

1) normally substrate name and “ase”
2) ATPase
3) lactase
4) cellulase
5) peroxidase
6) catecholase
7) kinase

Question 8

What happens in the active site?

Answer 8

1) binds and modifies substrate
2) complementary to substrate (fits like a puzzle)
3) substrate specificity

Question 9

Look at the diagrams

Answer 9

Please, gurrrrlllll

Question 10

Tell me about activation Energy.

Answer 10

1) initial investment of energy headed to start a reaction
2) exergonic- release more energy than what is absorbed initially
3) endergonic - absorb more energy than is released

Question 11

How does an exergonic graph look like?

Answer 11

it eventually rises and then the energy of the products are lower than the energy of the reactions (look at the notes, man)

Question 12

What does an endergonic graph look like?

Answer 12

The energy of the products end up be higher than the energy of the reactions (look at the notes, man)

Question 13

What does an Exergonic and enzyme look like?

Answer 13

a) enzyme lower EA needed to start a reaction
b) however, start and stop at same point
(look at the notes, man)

Question 14

What also lower the EA of endergonic reactions?

Answer 14

Enzymes

Question 15

• change in G is different in energy between what two things?`

Answer 15

reactants and products

Question 16

What are CoFactors?

Answer 16

1) non-organic molecules that binds to an enzyme
2) it activates the enzyme
3) can control enzyme activity by only providing co-factors when you need it
4) co-factor attaches by ionic bonds

Question 17

Tell me about them Kinases.

Answer 17

1) phosphorylate other protein
2) can inhibit or activate the protein
3) Phosphorous is covalently attached to another protein

Question 18

What enzyme changes the shape of molecule?

Answer 18

kinase

Question 19

Enzyme activity increases in increase of heat up to a point, why?

Answer 19

energy causes energy, enzyme captures substrate, things, then lets go

Question 20

What happens when the temperature of an enzyme is too hot?

Answer 20

protein unravels (denatures) and it may have no active site on enzyme

Question 21

Can temporarily denature if not too hot.. why?

Answer 21

cooling can allow renaturation

Question 22

What is the optimal temperature for most human enzymes?

Answer 22

35 - 37 degrees Celsius

Question 23

What happens if the pH is too acidic in enzyme solution?

Answer 23

they repel each other (too many +)

Question 24

What happens if the pH is too acidic in enzyme solution?

Answer 24

too many OH-

Question 25

What is the optimal pH?

Answer 25

a) 7.4 for most enzymes

b) pepsin (stomach enzyme) works best at pH 2

Question 26

What are the two sites in allosteric enzymes?

Answer 26

a) active site binds substrate
b) allosteric site binds to
1) inhibitor (stops enzyme)
2) activator (start enzyme)

Question 27

what is the main purpose of the allosteric enzymes?

Answer 27

to regulate enzyme activity

Question 28

what is usually used in a multi reaction pathway?

Answer 28

allosteric enzymes

Question 29

what is usually the 1st in the pathway?

Answer 29

allosteric enzyme

Question 30

what happens after the 1st pathway thing?

Answer 30

the allosteric inhibitor binds and change shape of active site

Question 31

what is generally the last product in pathway?

Answer 31

allosteric inhibitor

Question 32

when is D is not present, the enzyme is on or off?

Answer 32

on

Question 33

why allosteric?

Answer 33

a) makes the system more energy efficient

b) but making too much of “D”

Question 34

there is high energy in phosphate bonds: if you break it what will happen?

Answer 34

you will release energy