Chapter 17

Question 1

What are 4 important facts about catabolism

Answer 1

1. it is the breakdown of compounds (think cannibalism)
2. It is an oxidative process (think CO has cannibals)
3. It is the formation of energy (ADP + Pi = ATP)
4. It is converging (cannibals converge)

Question 2

What are 4 important facts about anabolism

Answer 2

1. It is the synthesis of compounds (think Ana brings people together)
2. It is a reductive process (think Ana reduces tension)
3. It requires energy (ATP goes to ADP + Pi)
4. It is diverging

Question 3

Metabolites

Answer 3

intermediates in metabolic pathways

Question 4

Allosteric inhibitors/activators

Answer 4

deal with the T/R states (think the stereo can be loud - tense - or low - relaxed)

Question 5

Covalent modification

Answer 5

deals with the A/B states (A= more active, B = less active)

phosphorylation and dephosphorylation

Question 6

Phosphorylation

Answer 6

done by using a kinase to add a phosphate group
brings a compound to the A (more active) state
ATP to ADP

Question 7

Dephosphorylation

Answer 7

done by using a phosphatase to remove a phosphate group
brings a compound to the B (less active) state
H20 to Pi

Question 8

Flux of material through metabolic pathways depend upon two things

Answer 8

1. amount of substrate and removal of product

2. activity of enzymes that catalyze the reactions

Question 9

Near equilibrium reactions

Answer 9

Q is about equal to the Keq
Reactions are readily reversible
Regulated by concentrations of substrates and products

Question 10

Irreversible reactions

Answer 10

Q is significantly lower than the Keq
Far from equilibrium
Not regulated by concentrations but by catalytic activity through allosteric regulation

Question 11

When Q is less than Keq that means that there is more (reactant/product) than (reactant/product)

Answer 11

Reactant than product

Question 12

Non equilibrium equation

Answer 12

Delta G = Delta G knot - RTln(Q)

Q = (Product/Reactant)

Question 13

Equilibrium equation

Answer 13

Delta G knot = RTln(Keq)

Question 14

Phosphoester bond

Answer 14

The low energy bond in ATP
(connection of phosphate to Adenosine)
(-O-P-O-CH2-)

Question 15

Phosphoanhydride bond

Answer 15

The high energy bonds in ATP
(connection between gamma, beta and alpha phosphates)
there are 4 of them (O-P-O-P-O-P-O-CH2))

Question 16

Phosphoryl transfer

Answer 16

Transferring the gamma phosphate and leaves behind a ADP

Question 17

Pyrophosphoryl transfer

Answer 17

Transferring the gamma and beta phosphates and leaves behind a AMP

Question 18

Adenylyl transfer

Answer 18

Transferring the alpha phosphate and the adenosine and leaves behind 2 inorganic phosphates

Question 19

3 reasons for the high free energy of ATP hydrolysis

Answer 19

1. Less charge repulsion in products
2. More resonance (more stable)
3. Products rapidly ionize

Question 20

Substrate level phosphorylation

Answer 20

ATP is generated directly by transfer of a phosphoryl group from a “high energy” compound
ADP + Pi (from high energy compound) forms ATP

Question 21

Oxidative phosphorylation

Answer 21

ATP is generated indirectly using the energy supplied through proton concentration gradients

Question 22

Kinases

Answer 22

Transfer phosphoryl groups to and from ATP

Question 23

Phosphate compounds with free energy more negative than -30kJ/mol

Answer 23

Considered “high energy” phosphate compounds

can donate phosphates to ADP to create ATP

Question 24

Phosphate compounds with free energy less negative than -30kJ/mol

Answer 24

Considered “low energy” phosphate compounds

ATP can donate phosphate to these compounds

Question 25

Phosphocreatine

Answer 25

Used to regenerate ATP rapidly in the muscle and nerve cells via action of creatine kinase
Example of near equilibrium reaction

Question 26

Thioesters and ATP have similar ___

Answer 26

free energies of hydrolysis

Question 27

Nucleoside diphosphate kinase

Answer 27

Takes ATP + NDP and turns it into ADP + NTP
Reversible reaction (near equilibrium)

Question 28

Nucleoside monophosphate kinase

Answer 28

Known as adenylate kinase
Takes 2 ADP and turns it into AMP + ATP
This is important because ADP accumulates when ATP is hydrolyzed