Respiration

Question 1

Describe the process of glycolysis

Answer 1

Phosphorylation of glucose using atp
Oxidation of triose phosphate into Pyruvate
Net gain of ATP
NAD produced

Question 2

Describe how oxidation takes place in glycolysis and in the Krebs cycle

Answer 2

Removal of hydrogen
By dehydrogenase
H+ accepted by NAD
in Krebs cycle FAD accepts it too

Question 3

Water is a waste product of aerobic respiration. Describe how water is formed at the end of aerobic respiration.

Answer 3

Oxygen is the final electron acceptor
Combines with electrons and protons

Question 4

Explain how the amount of ATP is increased by reactions occurring inside the mitochondria.

Answer 4

Oxidation
Of pyruvate
Forms acetyl coA
Substrate level production of ATP
reduced FADS and NADS produced
In matrix of mitochondria
Electrons go into electron transport chain
Through a series of redox reactions
Releasing energy
Protons moved into intermembrane space
ADP+Pi->ATP
ATP synthase

Question 5

Describe the role of coenzymes and carrier proteins in the synthesis of ATP. 5points

Answer 5

NADS and FADS reduced
Electrons move from coenzyme to carrier in electron transport chain
Energy released through a series of redox reactions
Used to pump H+ forming electrochemical gradient
Protons flow through ATP synthase to produce ATP

Question 6

Describe the event of oxidative phosphorylation. 5points

Answer 6

NADS and FADS reduced
Electrons moved from coenzyme to carrier in electron transport chain
Energy released through a series of redox reactions
Energy used to pump Protons forming electrochemical gradient
Protons move through ATP synthase forming ATP from ADP and Pi

Question 7

In many mammals ‘uncoupling protein’ help maintain a constant temperature during hibernation explain how.

Answer 7

Allow passage of protons
Energy released as heat

Question 8

The mitochondria has many cristae. Explain the advantage of this.

Answer 8

Increased surface area for electron carrier system
More ATP

Question 9

Give two reason why the respirometer was left for 10 minutes when it was first placed in the water bath.

Answer 9

Equilibrium reached
Allowing pressure changes due to gases
Allow respiration rate of seeds to stabilise

Question 10

Explain why a log scale is used to record the number of cells

Answer 10

Large range in numbers
Exponential increase

Question 11

Explain why converting pyruvate to lactate allows the continued production of ATP by anaerobic respiration.

Answer 11

Regenerates NAD
So glycolysis continues

Question 12

Malonate inhibits a reaction in the Krebs cycle. Explain why malonate would decrease the uptake of oxygen in a respiring cell

Answer 12

NADS and FADS not reduced
Oxygen is the final electron acceptor