Metabolic pathways and ATP production II

Question 1

What are the products of one turn of the TCA cycle?

Answer 1

3 x NADH
1 x FADH2
1 x GTP
2 x CO2

Question 2

Where are the Krebs’ Cycle enzymes found?

Answer 2

Mitochondrial Matrix

Question 3

Which Krebs’ Cycle enzyme is not found in this location?

Answer 3

Succinate Dehydrogenase

Question 4

What happens in Transamination?

Answer 4

An amine group is transferred between an amino acid and a keto acid to generate a new amino acid and keto acid (the basis of the malate-aspartate shuttle)
EXAMPLE: alanine + alpha-ketoglutarate  pyruvate + glutamate (enzyme = alanine aminotransferase)

Question 5

What are the two ways of electrons from NADH entering the mitochondrial matrix? Where are these two transport mechanisms found?

Answer 5

Glycerol Phosphate Shuttle – skeletal muscle, brain

Malata-Aspartate Shuttle – liver, kidney, heart

Question 6

Describe the glycerol phosphate shuttle.

Answer 6

Cytoplasmic glycerol-3-phosphate dehydrogenase transfers electrons from NADH to dihydroxyacetone phosphate converting it to glycerol-3-phosphate Glycerol-3-phosphate is converted by mitochondrial glycerol-3-phosphate back into Dihydroxyacetone phosphate and the electrons are passed via FAD to coenzyme Q

Question 7

What different types of reactions are NADPH and NADH involved in?

Answer 7

NADPH = Anabolic 
NADH = Catabolic

Question 8

What are the components involved in the malate-aspartate shuttle?

Answer 8

Malate (in)
Alpha-ketoglutarate (out) Oxaloacetate (converted from malate)
Glutamate (in)
Aspartate (out)