Respiration

Question 1

Describe the process of glycolysis

Answer 1

1) phosphorylation of glucose
2) oxidation of TP to Pyruvate
3) Net gain of ATP
4) NAD reduced

Question 2

describe how oxidation takes place in glycolysis and in the kreb cycle

Answer 2

1) removal of hydrogen/dehydrogenation
2) by enzymes/dehydrogenase
3) H accepted by NAD, reduced NAD formed
4) in krebs cycle, FAD (used as well)

Question 3

the mitochondria in muscles contain many cristae Explain the advantage of this

Answer 3

1) larger SA for electron carrier system / oxidative phosphorylation
2) provides more ATP / energy for muscle contraction

Question 4

what does glycolysis of glucose yield

Answer 4

• 2 NET atp directly by substrate level phosphorylation
• 2 reduced NAD
• 2 molecules of pyruvate

Question 5

what does each link reaction yield

Answer 5

• reduced NAD used to produce ATP by oxidative phosphorylation
• acetyl co A
• CO2
• as 2 molecules of pyruvate are produced from one molecule of glucose there will be 2 molecules of acetyl co A produced

Question 6

What does each kreb cycle yield

Answer 6

• 2x CO2 produced
• some atp produced directly by substrate level phosphorylation
• 3x reduced NAD + 1x FAD produced
• 1 molecule of glucose = 2 molecules acetyl coA so kreb cycle occur twice

Question 7

water is a waste product of aerobic respiration. Describe how water is formed at the end of aerobic respiration (2 marks)

Answer 7

1) oxygen is terminal / final e- acceptor
2) combines with e- and protons to form water

Question 8

describe substrate level phosphorylation

Answer 8

ATP generated directly through energy released via respiration reactions. occurs in glycolysis

Question 9

define oxidative phosphorylation

Answer 9

ATP generated from chemical energy released when a reduced hydrogen carrier or coenzyme has been oxides at the the electron transport chain

Question 10

Describe how ATP is made in the mitochondria

Answer 10

1. Substrate level phosphorylation / ATP produced in Krebs cycle;
   Accept alternatives for reduced NAD
2. Krebs cycle / link reaction produces reduced coenzyme / reduced NAD / reduced FAD;
3. Accept description of either Krebs cycle or link reaction
4. Electrons released from reduced / coenzymes / NAD / FAD
5. (Electrons) pass along carriers / through electron transport chain / through series of redox reactions;
6. Energy released;
7. Allow this mark in context of electron transport or chemiosmosis
8. ADP / ADP + Pi;
9. Accept H+ or hydrogen ions and cristae
10. Protons move into intermembrane space;
11. Allow description of movement through membrane
12. ATP synthase;
13. Accept ATPase. Reject stalked particles

Question 11

Describe the events of oxidative phosphorylation

Answer 11

• NAD/FAD reduced / hydrogen attached to NAD/FAD;
• H+ ions/electrons transferred from coenzyme to coenzyme/carrier to carrier (ETC on cristae of inner membrane)
• Energy released (from electrons) through series of redox reactions;
• Energy released used to pump H+/ protons into intermembrane space;
• H+/ protons flow back through ATP synthase to produce ATP from ADP and phosphate.