Exam3- L27- HMP shunt

Question 1

What is the outline of the HMP shunt, galactose metabolism and fructose metabolism?

Answer 1

Question 2

What/why/when/where/who/how of HMP shunt

Answer 2

Question 3

What is the starting substrate, pathway final products, enzymes, enzyme regulation, and purpose of the OXIDATIVE branch of the HMP shunt? When is it mostly active

Answer 3

Question 4

What is the starting substrate, pathway final products, enzymes, enzyme regulation, and purpose of the NON-OXIDATIVE (FORWARD) branch of the HMP shunt? What are the interconversions of sugars?

Answer 4

Question 5

What is the starting substrate, pathway final products, enzymes, enzyme regulation, and purpose of the NON-OXIDATIVE (REVERSE) branch of the HMP shunt? What are the interconversions of sugars?

Answer 5

Question 5

What accumulates in the fed state? What is an inhibitor of PFK-1? What accumulates to force what branch to activate?

Answer 5

Question 6

What is NADPH required for? How can it be acquired without mitochondria??

Answer 6

Question 7

Answer 7

Q1

Question 8

What are ROS and glutathione for? What provides electrons for the reduction of hydrogen peroxide?

Answer 8

Question 9

Galactose metabolism- what is the source of galactose? Why do we need it? How is it obtained without dietary galactose?

Answer 9

Question 10

Galactose metabolism- What is the endogenous and exogenous source of galactose?

Answer 10

Question 11

Galactose metabolism- what are the first 2 steps? What are the enzymes that help?

Answer 11

Question 12

Galactose metabolism- What is the 3rd step? What is the C4 epimer of UDP-gla? What is it used for?

Answer 12

Question 13

What can UDP galactose be used to synthesize? What is the role of aldose reductase?

Answer 13

Question 14

What happens with a GALK deficiency?

Answer 14

Question 15

What happens with a GALT deficiency within the pathway?

Answer 15

Question 16

With a GALT deficiency what are the biochemical steps affected upon galactose consumption?

Answer 16

Question 17

What is the clinical presentation of a GALT deficiency? What is the therapy?

Answer 17

Question 18

Why should populations be screened for galactosemia?

Answer 18

Question 19

What are the major dietary sources of fructose? How does fructose enter into cells? How is it metabolized?

Answer 19

Question 20

What are the first 2 steps to fructose metabolism? What are the important enzymes?

Answer 20

Question 21

Elevated levels of fructose do what to the liver? Why?

Answer 21

Question 22

What happens with a fructokinase deficiency?

Answer 22

Question 23

What happens with a hepatic aldolase B deficiency? What is the presentation? What is the therapy?

Answer 23