Gluconeogenesis

Question 1

What are the three common sources for carbon skeletons?

Answer 1

1) lactate: produced in RBC and skel m
2) AAs (alanine): derived from muscle protein
3) glycerol: released from TAGs during lipolysis in adipose tissue

Question 2

When does gluconeogenesis run? Why?

Answer 2

all the time (at low levels) to clear lactact continually produced by RBC

Question 3

Which 2 organs contribute to glucose formation?

Answer 3

Liver (MOSTLY)
Kidney ~10%
Muscle’s only contribution is alanine

Question 4

What 4 enzymes are unique to gluconeogenesis?

Answer 4

1) Pyruvate carboxylase (mitochondrial)
2) phosphoenal carboxykinase (cyto and mito)
3) F,1,6-BP (cyto)
4) G6Pase (ER)

Question 5

What (3 things) are required for oxaloacetate synthesis?

Answer 5

ABC Carboxylase:
A for ATP
B for Biotin
C for CO2

NB: eating raw eggs can cause biotin deficiency bc avidin (protein in egg whites) binds tightly to biotin