Lipids

Question 1

basic outline of how to make acetyl CoA from fatty acids?

Answer 1

1) make fatty acyl CoA species
2) shuttle this molecule into the mitochondria via the Carnitine shuttle
3) beta oxidation

Question 2

equation for making a fatty acyl CoA species and enzyme

Answer 2

fatty acid + ATP + HS-CoA —> fatty acid-CoA + AMP +PPi

enzyme: acyl CoA synthetase

Question 3

why does the carnitine shuttle exist?

Answer 3

to get the acyl CoA species into the mitochondria

Question 4

Outline the mechanism of then carnitine shuttle

Answer 4

carnitine —> acyl carnitine by the cytoplasmic enzyme carnitine acyltransferase I

The acyl carnitine enters the mitochondria via a translocase

A mitochondrial version of the enzyme converts the acyl carnitine back into carnitine which regenerates the Acyl CoA species.

The carnitine is then transported back out the mitochondria via the translocase.

Question 5

What are the four reactions that occur to the fatty acid in beta oxidation to make acetyl CoA molecules?

Answer 5

1) Oxidation
2) Hydration
3) Oxidation
4) Thiolysis

Question 6

What are the 3 enzymes that you need to know in the beta oxidation cycle

Answer 6

1) 3- hydroxyacyl CoA hydrolase
2) L- 3-hydroxyacyl CoA dehydrogenease
3) beta -ketothiolase

Question 7

how many cycles of beta oxidation required to break down palmitoyl CoA?

what is the overall equation?

Answer 7

7

palmitoyl CoA + 7FAD + 7NAD + 7H20 + 7CoA —> 8 Acetyl CoA + 7NADH + 7FADH2

Question 8

What are the four reactions is lipogenesis?

Answer 8

1) decarboxylative condensation
2) reduction
3) dehydration
4) reduction

Question 9

what is the function of ACP?

Answer 9

acyl carrier protein acts a swinging protein which moves fatty acid chains from one domain to another