Chapter 24 (Fatty Acid Biosynthesis)

Question 1

The difference between Beta-Oxidation and Biosynthesis enzymes

Answer 1

Beta-Oxidation enzymes are all separate water soluble proteins in the matrix Biosynthesis enzymes are all connected on one long chain in the cytosol

Question 2

FA BS occurs in which locations and what is required

Answer 2

Liver and adipose tissue Requires: Acetyl-CoA, Citrate-malate-pyruvate shuttle, NADPH, and cytosolic ATP

Question 3

How we get to Acetyl-CoA in: carbs FAs AAs

Answer 3

PDH in the matrix Beta-oxidation in the matrix matrix

Question 4

Acetate units are activated by the formation of ___ at the expense of ATP

Answer 4

Malonyl-CoA

Question 5

Acetyl-CoA Carboxylase (ACC)

Answer 5

First committed step to FA biosynthesis Carboxylation of Acetyl-CoA to from Malonyl-CoA Requires: ATP Produces: ADP + Pi Uses biotin and bicarbonate Irreversible

Question 6

Allosteric regulation of ACC

Answer 6

+ Citrate - LCFAcyl-CoA (such as Palmitoyl-CoA)

Question 7

Hormonal control of ACC

Answer 7

inactive when phosphorylated (can be phosphorylated multiple times) Citrate partly activates a phosphorylated ACC

Question 8

Effect of phosphorylation of ACC

Answer 8

Unphosphorylated ACC has a high affinity (low Kd) for citrate

Question 9

ACP stands for

Answer 9

Acyl Carrier Protein Carries intermediates in FA synthesis

Question 10

Before FA BS begins, FA synthetase must be primed with ___ via the enzyme ___

Answer 10

acetyl-CoA acetyl transacylase

Question 11

After 7 rounds of FA BS we use ___ to cleave off ___

Answer 11

thioesterase Palmitate

Question 12

FA BS enzymes only function:

Answer 12

in a head-to-tail fashion

Question 13

The net rxn of the FA BS of acetyl-CoA to Palmitate (16C chain)

Answer 13

8 Acetyl-CoA + 7 ATP + 14 NADPH + 6H+ + H2O (arrow) Palmitate + 14 NADP+ + 7 ADP + 7 Pi + 8 CoA

Question 14

Role of Glucagon in ACC regulation

Answer 14

Released because of low glucose in blood turns of ACC (stops FA BS) mobilizes FA in bloodstream