FMS 1 review

Question 1

What are the precursors of gluconeogenesis?

Answer 1

Lactate, amino acids, glycerol

Question 2

Where does the energy come from for gluconeogenesis?

Answer 2

Requires 6 ATP lactate–>glucose. from FA oxidation.

Question 3

What happens if Glucose 6 phosphate dehydrogenase is deficient?

Answer 3

No NADPH. Can’t convert Converted oxidized glutathion (GSSG) to GSH on cell membranes (keeps membrane flexible). Leads to hemolytic anemia in RBCs.

Question 4

Galactosemia is caused by deficiency in what enzyme?

Answer 4

Galactose-1-phosphate uridyl transferase

and galactose.

Question 5

what reaction does Pyruvate dehydrogenase catalyze?

Answer 5

pyruvate + NAD+ –>acetyl coA +NADH

Question 6

How is PDH regulated?

Answer 6

Feedback inhibition: acetyl CoA and NADH inhibit E1 and stimulate PDH kinase
Activation of PDH: Pyruvate, CoA, NAD, and ADP inhibit PDH kinase

Question 7

When and where are FAs made?

Answer 7

In the well fed state and in every tissue except RBCs. Major site is the liver

Question 8

How is FA synthesis regulated?

Answer 8

By acetyl CoA carboxylase.
Active form = unphosphorylated!
Inhibited by: Product= malonyl CoA
Activated by: Citrate

Question 9

What enzyme catalyzes the acetyl coA–>Malonyl coA

Answer 9

acetyl coA carboxylase

Question 10

How is cholesterol synthesis regulated?

Answer 10

by enzyme HMG-CoA reductase. Catalyzes rate limiting step.
SREBP=sterol receptor element binding protein. It becomes a transcription activating factor for HMG coA reductase and LDL receptor.
Insulin and glucagon.