Lecture 8 - Galactose, Fructose, and Ethanol Metabolism

Question 1

Which is not a major source of fructose?

A. Table sugar
B. High fructose corn syrup
C. Honey
D. Dairy products
E. Fruits

Answer 1

D - milk and dairy products are a major source of galactose

Question 2

_________, which are found in the extracellular matrix, are biologically important compounds that require galactose in order to be synthesized.

A. Glycoproteins
B. Glycolipids
C. Proteoglycans
D. Lactose

Answer 2

C. All others also require galactose but proteoglycans are found in the EC matrix.

Question 3

Almost all of the assimilation of galactose into the mainstream of carb metabolism is in the _______.

Answer 3

liver

Question 4

_____________ alters the configuration around the 4-carbon unit in UDP-Gal to generate UDP-glu.

A. Galactokinase
B. Uridyl transferase
C. UDP-Glu-4-Epimerase
D. Fructokinase
E. Aldolase B
F. Glyceraldehyde kinase

Answer 4

C

Question 5

__________ transfers phosphate from ATP to the C1 of galactose, which generates galactose-1-phosphate.

A. Galactokinase
B. Uridyl transferase
C. UDP-Glu-4-Epimerase
D. Fructokinase
E. Aldolase B
F. Glyceraldehyde kinase

Answer 5

A

Question 6

____________ catalyzes an exchange reaction in which Gal-1-P is exchanged for the glu-1-P moiety of UDP-glucose. The products are UDP-Gal and glu-1-P.

A. Galactokinase
B. Uridyl transferase
C. UDP-Glu-4-Epimerase
D. Fructokinase
E. Aldolase B
F. Glyceraldehyde kinase

Answer 6

B

Question 7

Which two enzymes result in galactosemia if they are deficient?

Answer 7

1. Uridyl transferase (most common)

2. Galactokinase (rare)

Question 8

How is a galactokinase deficiency distinguished from a uridyl transferase deficiency?

Answer 8

Galactokinase deficiency lacks the impact on hepatic glucose metabolism (compared to a uridyl transferase deficiency).

Question 9

__________ converts fru-1-P to either DHAP or glyceraldehyde.

A. Galactokinase
B. Uridyl transferase
C. UDP-Glu-4-Epimerase
D. Fructokinase
E. Aldolase B
F. Glyceraldehyde kinase

Answer 9

E

Question 10

____________ phosphorylates glyceraldehyde to GAP.

A. Galactokinase
B. Uridyl transferase
C. UDP-Glu-4-Epimerase
D. Fructokinase
E. Aldolase B
F. Glyceraldehyde kinase

Answer 10

F