Carb III

Question 1

Where are the two sites of gluconeogenesis?

Answer 1

Mostly liver but in cases of extreme starvation, the kidney

Question 2

What enzymes of glycolysis are directly bypassed during gluconeogenesis?

Answer 2

hexokinase, phosphofructokinase

Question 3

What are the three most utilized substituents for GNG?

Answer 3

lactate, alanine and glycerol

Question 4

What must acetyl-CoA be converted into to be used for GNG?

Answer 4

oxaloacetate

Question 5

What enzyme of GNG bypasses hexokinase?

Answer 5

glucose-6-phosphatase

Question 6

What enzyme of GNG bypasses phosphofructokinase?

Answer 6

fructose 1,6-bisPhosphatase

Question 7

WHat is the function of pyruvate carboxylase?

Answer 7

to convert pyruvate into OAA

Question 8

What is the function of PEP carboxykianse?

Answer 8

to convert OAA into phosphoenolpyruvate

Question 9

What are the three regulated enzymes of GNG?

Answer 9

PEPCK, F16bP-ase, G6P-ase

Question 10

What is the main regulated step of GNG?

Answer 10

fructose-1,6-bisPhosphatase

Question 11

What two metabolic enzymes are regulated by Acetyl-CoA?

Answer 11

inhbits pyruvate dehydrogenase and activates pyruvate carboxylase

Question 12

Why do defects in GNG present with lactic acidosis?

Answer 12

lactate is one of three (alanine and glycerol) building blocks of glucose during GNG

Question 13

A defect in what enzyme will present with fasting hypoglycemia and metabolic acidosis?

Answer 13

Fructose-1,6-bisPhosphatase

Question 14

What reducing equivalent can inhibit GNG?

Answer 14

NADH

Question 15

What is lactose synthesized from?

Answer 15

glucose and UDP-galactose

Question 16

Lactose synthase is a heterodimer of what two components?

Answer 16

Alpha-lactallbumin and beta-galactosyltransferase

Question 17

What is the function of the pentose phosphate pathway?

Answer 17

Production of NADPH and riboses

Question 18

What is the function of G6P dehydrogenase?

Answer 18

conversion of G6P into 6-phosphogluconolactone

Question 19

What is the function of lactonase?

Answer 19

conversion of 6-phosphogluconolactone into 6-phosphogluconate

Question 20

What is the function of 6-phosphogluconate dehydrogenase?

Answer 20

coversion of 6-phosphogluconate into ribulose-5-phosphate

Question 21

What two products of the non-oxidative phase of PPP can be funneled into glycolysis?

Answer 21

F6P and GA3P

Question 22

What is the regulated step of the PPP?

Answer 22

conversion of G6P to 6-phosphogluconolactone

Question 23

What product inhibits the action of G6P Dehydrogenase?

Answer 23

NADPH

Question 24

What group of people are most likely to suffer an enzymatic defect in the G6P dehydrogenase?

Answer 24

african american men

Question 25

What tissue is overly susceptible to deficiencies in G6P dehydrogenase inactivity

Answer 25

RBCs

Question 26

What molecule contributes to RBC destruction?

Answer 26

H2O2

Question 27

What scenarios can raise H2O2 and make RBCs more susceptible to lysis?

Answer 27

Infections: macrophages produce H2O2

Fava beans

H2O2 producing drugs (primaquine)

Question 28

What vitamin is required for the transketolase reactions of the PPP?

Answer 28

Thiamine (B1)

Question 29

What vitamin is required for transketolase reactions of non-oxidative PPP?

Answer 29

thiamine