respiration

Question 1

what are the three stages in respiration

Answer 1

-glycolysis
-link reactiom
-krebs cycle

Question 2

describe glycolysis

Answer 2

-glucose is phosphorylated to activate it. in this 2 ATP molecules are converted into ADP +Pi to provide to phosphate groups
-the phosphorylated glucose is unstable so splits into 2 TP molecules.
-TP is then oxidised into pyruvate and while this happens dehydrogenase reduces NAD into NADH2 and ATP is also produces by substrate level phosphorylation.

Question 3

describe link reaction process

Answer 3

-pyruvate is actively transported into the mitrochondrial matrix
-pyruvate is oxidised into acetate and the hydrogen removed reduces NAD into NADH2 (reducedNAD). and removes a CO2 molecule (carboxylation)
-co enzyme A binds to acetate to form acetylcoenzyme A.

Question 4

Describe the Krebs cycle

Answer 4

AcetylCoA combines with a 4 C molecule to form a 6 C compound. Then carboxylase loses a CO2 so becomes a 5 C compound and while this happens NAD is reduced into NADH + H^+. Then the 5C compound loses another carbon due to carboxylase. And in this process ATP is produced due to substrate level phosphorylation and 2x NAD is reduced into 2x NADH+H+ and FAD is also reduced into FADH2. This produces a 4 carbon compound then the cycle repeats again as the actylCoA binds to it

Question 5

Describe how oxidation takes place in glycolysis and in Krebs cycle

Answer 5

The removal of hydrogen by the enzyme dehydrogenase forms reduced NAD And in Krebs also produces reduces FAD when dehydrogenase reduces FAD