Chapter 15 Notes

Question 0

Anabolism?

Answer 0

Useful energy + simple precursors –> complex molecules

Question 1

Catabolism?

Answer 1

Fuels (carbohydrates, fats) –> CO2 + H2O + useful energy

Question 2

Whether or not a reaction occurs depends on what 2 parameters?

Answer 2

1) two reactions can be coupled 2) the overall free energy charge for coupled reactions is equal to the sum of the free energy changes of the individual steps

Question 3

If a reaction is thermodynamically unfavorable how can it be driven forward?

Answer 3

By coupling it with a thermodynamically favorable reaction

Question 4

What do reactions using energy coupling often involve?

Answer 4

The hydrolysis of ATP

Question 5

ATP + H2O –> ?

Answer 5

ADP + Pi

AMP + PPi

Question 6

When can energy be released more when undergoing substrate-level phosphorylation?

Answer 6

When the standard energy in cellular processes has greater ATP

Question 7

Why can ATP be stored until needed?

Answer 7

It is kinetically stable

Question 8

Energy is stored in what form?

Answer 8

ATP

Question 9

What does the energy charge tell you?

Answer 9

How much ATP is present (how much energy is present)

Question 10

The intermediate position of ATP allows for what?

Answer 10

It enables ATP to function efficiently as a carrier of phosphoryl groups.

Question 11

Why are ATP and other compounds activated carriers of phosphoryl groups?

Answer 11

Because the transfer of phosphoryl groups is exergonic

Question 12

What is the chemical energy currency in the cell based on?

Answer 12

Phosphate

Question 13

How does ATP hydrolysis couple to unfavorable reactions?

Answer 13

With the reaction of enzymes. ATP releases a phosphate group when hydrolyzed and the enzyme readjusts itself so other reactants are more favorable and energy is transferred and raised so the reaction will move forward.

Question 14

The energy status of any given cell is manifested by what?

Answer 14

energy charge

Question 15

Oxidation ____ energy.

Answer 15

Generates

Question 16

What is the difference between energy of the reactants and products?

Answer 16

The energy extracted during oxidation

Question 17

Why will fatty acids lose the most amount of energy?

Answer 17

Because they have more carbons and more hydrogens attached

Question 18

Are fatty acids or carbohydrates easier to break down? Why?

Answer 18

CHOs because they are more branched and accessible. Enzymes can go to branches more easily to break down components of energy

Question 19

What does biosynthesis require?

Answer 19

NADP+

Question 20

What does energy production require?

Answer 20

NAD+

Question 21

The extraction of fuels can be divided into what three stages?

Answer 21

Stage I
1) fats --> fatty acids and glycerol
2) polysaccharides --> glucose and other sugars
3) proteins --> amino acids
Stage II
All the above to acetyl CoA
Stage III
Citric acid cycle

Question 22

What two compounds serve as 2 electron acceptors in oxidation and reduction reactions?

Answer 22

NADP+

NAD+

Question 23

What are the enzymes that catalyze reactions using NAD+ and NADP+ as a coenzyme?

Answer 23

Dehydrogenases and oxidoreductases

Question 24

NAD+ follows what mechanisms?

Answer 24

Catabolism and energy production

Question 25

What mechanisms are involved in NADP+?

Answer 25

Reducing power for biosynthesis