7.5

Question 1

Give a definition of decarboxylation

Answer 1

The removal of a carbon dioxide from a larger organic molecule

Question 2

Give a definition of dehydrogenation

Answer 2

The removal of hydrogen from a larger organic molecule

Question 3

Locations of the link reaction and Kreb’s cycle
a) state where they take place
b) and why they take place here

Answer 3

Link reaction and Krebs cycle - matrix in the mitochondria, to produce reactants for next part of respiration

Question 4

Describe what happens during the link reaction

Answer 4

Pyruvate reacts with NAD to produce CO2, acetyl coenzyme A and reduced NAD

Question 5

Describe what happens during the Krebs cycle

Answer 5

Acetyl coA reacts with oxaloacetate to produce citrate 6c
Which is then decarboxylated and dehydrogenated twice, producing 2NADH and 2CO2
The 4C chain is decarboxylated and dehydrogenated again to produce NADH, FADH and ATP and reproduce oxaloacetate

Question 6

State the role of reduced NAD and FAD

Answer 6

To dehydrogenate the carbon chains, allowing for the removal of CO2

Question 7

Explain why the link reaction and Krebs cycle con only occur if there is sufficient oxygen present

Answer 7

To for CO2, O2 is needed in surplus, otherwise the citrate cannot be decarboxylated