T2 L2: Role of ATP in living cells 1

Question 1

What does anabolism mean?

Answer 1

Synthesis of complex molecules from simpler ones (‘genesis’ reactions)

Question 2

What does Catabolism mean?

Answer 2

Breakdown of energy-rich molecules to simpler ones (‘Lysis’ reactions)

Question 3

What does isothermal mean?

Answer 3

Maintaining a constant temperature

Question 4

When can the flow of heat be used a source of energy?

Answer 4

When it passes to an object or area of lower energy

Question 5

What is meant by ‘free’ energy?

Answer 5

Energy available to do work

Question 6

What is the equation for Gibbs free energy?

Answer 6

ΔG= ΔH - TΔS (G= Gibbs free energy, H= enthalpy, S= Entropy, T= temperature)

Question 7

What is enthalpy?

Answer 7

Energy that can be found in chemical bonds

Question 8

What is entropy?

Answer 8

Disorder of molecules

Question 9

What is meant by a Gibbs free energy (ΔG) of a reaction?

Answer 9

The maximum energy that can be obtained from a reaction at constant temperature and pressure

Question 10

What happens in a chemical reaction if the [products] is greater than the [reactants]?

Answer 10

Spontaneous/ exergonic (exothermal) reaction (ΔG < 0)

Question 11

What happens in a chemical reaction if the [reactants] is greater than the [products]?

Answer 11

Unfavourable/ endergonic (Endothermal) reaction (ΔG > 0)

Question 12

When can chemical reactions be coupled?

Answer 12

When they have common intermediates

Question 13

What is ATP associated with in the cytosol and why?

Answer 13

To a Mg2+ complex because Mg2+ interacts with O2 of the triphosphate chain making it more susceptible to cleavage by phosphorylation. Without Mg2+, cleavage doesn’t happen efficiently

Question 14

What is SLP?

Answer 14

Substrate level phosphorylation is the formation of ATP by phosphate group transfer from a substrate of ADP

Question 15

What do oxidoreductases do?

Answer 15

Transfer e-

Question 16

What do transferases do?

Answer 16

Transfer functional groups

Question 17

What do hydrolases do?

Answer 17

Add H2O

Question 18

What do Lyases (Synthases) do?

Answer 18

Cleave or form bonds

Question 19

What do Isomerases do?

Answer 19

Transfer groups within a molecule

Question 20

What do Ligases (Synthetases) do?

Answer 20

Form bonds coupled to ATP hydrolases

Question 21

What are co-factors?

Answer 21

Non-protein molecules necessary for enzyme activity mostly derived from vitamins. They are loosely associated with their enzyme and are able to diffuse between enzymes carrying e-

Question 22

What are prosthetic groups?

Answer 22

Non-protein co-factors that are covalently bound to the enzyme. They’re not released as part of the reaction and act as temporary stores for e- or intermediates

Question 23

What are 2 differences between co-enzymes and prosthetic groups?

Answer 23

Prosthetic groups are covalently bonded, co-factors are loosely associated. Co-factors can diffuse between enzymes carrying e-, prosthetic groups store e-

Question 24

What is the co-enzyme of vitamin B2 (Riboflavin)?

Answer 24

FAD or FMN (prosthetic group)

Question 25

What is the co-enzyme of vitamin B3 (Niacin)?

Answer 25

NAD+ (Co-substrate)

Question 26

What does NAD stand for?

Answer 26

Nicotinamide adenine dinucleotide

Question 27

Where does glycolysis happen?

Answer 27

In the cytosol

Question 28

Out of the priming stages, which molecule continues to glycolysis?

Answer 28

G-3-P (Glyceraldehyde-3-phophate)

Question 29

What is the role of Hexokinase (Hk) in the priming stages of glycolysis?

Answer 29

Phosphorylates glucose into glucose-6-phophate (G-6-P) using ATP

Question 30

What is the role of phosphofructose kinase (PFK-1)

Answer 30

Phosphorylates fructose-6-phosphate (F-6-P) into fructose-1,6-bisphosphate (FBP)

Question 31

What is the role of pyruvate kinase (Pk) in the glycolysis pay-off reaction?

Answer 31

It converts phosphoenolpyruvate into pyruvate in a reaction that produces ATP

Question 32

What is meant by the priming and payoff reactions of glycolysis?

Answer 32

Priming involves investing some ATP and then the payoff reactions recover the lost ATP

Question 33

Under aerobic conditions, what happens to pyruvate in a reaction?

Answer 33

Oxidation and complete degradation

Question 34

What happens to pyruvate in hypoxic conditions?

Answer 34

It’s reduced to lactate