Thompson

Question 0

What does glutathione peroxidase do and how is it recycled?

Answer 0

Glutathione peroxidase reduces H2O2 free radical into water and becomes oxidized. NADPH recycles glutathione peroxidase by reducing through glutathione reductase

Question 1

What are some cellular defenses against free radicals?

Answer 1

1. H2O2 + H202 -(catalase)-> 2H20 + O2

2. Glutathione peroxidase converts H2O2 into 2H2O

Question 2

What is TPP and when is it used?

Answer 2

Thiamine Pyrophosphate (a cofactor) is used in 3 pathways:

1. TCA cycle (alpha-ketoglutarate dehydrogenase enzyme)
2. Pyruvate dehydrogenase (makes Acetyl CoA)
3. Pentose Phosphate Pathway (transketolase - 2 carbon transfers)

Question 3

What are some functions of NADPH?

Answer 3

1. Reductive/ synthetic pathways i.e. steroid and fatty acid synthesis
2. Free radical defense i.e. recycles glutathione peroxidase
3. Drug detoxification i.e. P450
4. Phagocytosis and superoxides
5. Produces nitric oxide NO

Question 4

What is the regulatory and irreversible step of Pentose Phosphate Pathway?

Answer 4

Glucose 6 phosphate -> Ribulose 5 Phosphate + 2 NADPH + CO2 through the enzyme Glucose 6 Phosphate Dehydrogenase