Topic Five - Processes

Question 1

what are the four steps of respiration?

Answer 1

1. glycolysis
2. link reaction
3. kerb cycle
4. electron transport chain

Question 2

where does glycolysis take place?

Answer 2

cytoplasm

Question 3

what is the products of glycolysis?

Answer 3

2 pyruvate, 2 NADH, 2 ATP

Question 4

what is the first step of glycolysis?

Answer 4

Phosphorylation:
- glucose is phosphorylated by 2 ATP molecules to form hexose biphosphate (6C)
- phosphorylation make the molecule less stable = more reactive

Question 5

what is the second step of glycolysis?

Answer 5

lysis:
- hexose biphosphate is converted into 2 triose phosphate (3C)

Question 6

what is the third step of glycolysis?

Answer 6

oxidation:
- H is removed from triose phosphate via oxidation
- 2 NAD are reduced to 2 x NADH

Question 7

what is the forth step of glycolosis?

Answer 7

ATP formation:
- 4 x ATP released when triose phosphate is converted to pyruvate

Question 8

where does the link reaction happen?

Answer 8

matrix

Question 9

what are the products of the link reaction?

Answer 9

Acetyl CoA + NADH + CO2

Question 10

what are the steps of the link reaction?

Answer 10

Pyruvate turns into acetylcoenzyme A
2 H leave to turn NAD to NADH
Oxygen leaves, and binds to carbon to form CO2
Co A comes in to make Acetyl coenzyme A

Question 11

where does the kerb cycle take place?

Answer 11

matrix

Question 12

what are the products of the kreb cycle?

Answer 12

2 x CO2
1 x ATP
3 x NADH
1 x FADH2

Question 13

what is the first stage of the kreb cycle?

Answer 13

Acetyl CoA combines with a 4C molecule (oxalacetate) to form a 6C molecule (citric acid)

Question 14

what is the second stage of the kreb cycle?

Answer 14

via oxidation/reduction reactions the 4C molecule is regenerated
1. after citric acid is formed,
NAD -> NADH + CO2, (1C is lost)
2. a 5C molecule is produced
3. NAD -> NADH + CO2 (1C is lost)
4. 4C molecule is made
5. ADP + Pi -> ATP
6. FAD -> FADH2
7. NAD -> NADH
8. 4C molecule left now is oxalacetate

Question 15

where does electron transport chain take place?

Answer 15

cristae

Question 16

what are the products of ETC?

Answer 16

28 x ATP
H20

Question 17

what are the two stages of the ETC?

Answer 17

Chemiosmosis and Oxidative Phosphorylation

Question 18

what happens in chemiosmosis?

Answer 18

1. H carriers donate e- to the e- carriers on the inner membrane of cristae
2. e- lose their E as they’re passed along the ETC
3. The E is used to pump p+ not the inner membrane space
4. build up of p+ = proton motive force
5. p+ return to the matrix via facilitated diffusion through the channel protein ATP synthase

Question 19

what happens in oxidative phosphorylation?

Answer 19

1. ATP synthase generates ATP
2. to maintain electrochemical gradient, de-energised e- are removed from the ETC
3. oxygen accepts the e- and binds with free protons to form H2O
   -> this maintains the H+ gradient