Unit 5A

Question 1

Site of catabolism:

Site of anabolism

Answer 1

Catabolism- mitochondria

Anabolism- cytosol

Question 2

Catabolism produces:

Answer 2

Acetyl-CoA and NADH (reducing power)

Question 3

Anabolism requires:

Answer 3

Acetyl-CoA
Malonyl-CoA
Reducing power from NADPH

Question 4

What happens in the cytosol

Answer 4

NADPH production

Storage of NADPH/NADP+

Isoprenoid and sterol synthesis (early stages)

Fatty acid synthesis

Question 5

What happens in the mitochondria in animals and yeast cells

Answer 5

Fatty acid oxidation

Acetyl-CoA production

Ketone body synthesis

Fatty acid elongation

Question 6

What happens in the ER

Answer 6

Phospholipid synthesis

Sterol synthesis (late stages)

Fatty acid elongation

Fatty acid desaturation

Question 7

Fatty acid synthesis occurs where?

Answer 7

In cell compartments where NADPH levels are high and available for reductive synthesis (Cytosol for animals)

Question 8

Sources of NADPH in adipocytes:

Answer 8

Pentose phosphate pathway (PPP) and malic enzyme.

Here NADPH made as malate converts to pyruvate + CO2

Question 9

Sources of NADPH in hepatocytes and mammary gland

Answer 9

Pentose phosphate pathway (PPP)

Here, NADPH is made as glucose-6-phosphate converts to ribulose-6-phosphate

Question 10

2 routes to produce NADPH and their catalyst

Answer 10

1- Malate to pyruvate. Coenzyme: Malic enzyme

2- Glucose-6-phosphate to ribulose-5-phosphate.
Coenzyme: PPP

Question 11

Steps in fatty acid biosynthesis

Answer 11

1- Shuttle of acetyl-coa to cytosol via citrate shuttle

2- Carboxylation of acetyl-coa to malonyl coa via acetyl-coa carboxylase (ACC)

3- Reactions of FA syntheses (remember CRDR)

Question 12

How is acetyl-coa transported into the cytosol for FA synthesis?

Answer 12

Acetyl-coa is converted to citrate with oxaloacetate (catalyzed by citrate synthase)

Citrate then passes through the citrate transporter

Question 13

Citrate in the cytosol is cleaved by _____ _____, regenerating:

Answer 13

citrate lyase

acetyl-coa and oxaloacetate (Reaction requires ATP)

Acetyl Coa can now be used for lipid synthesis

Question 14

Malate dehydrogenase in the cytosol reduces to:

Answer 14

malate

Question 15

In the cytosol, what can happen to malate?

Answer 15

It can be converted to NADPH and pyruvate via the malic enzyme

or it can be converted back to the mt via malate-a-ketogluterate transporter

Question 16

NADPH is used for

Answer 16

lipid synthesis