Question

UDP glucose is required for glycogen synthesis and which of the following pathways?

a. Galactose metabolism

b. Fructose metabolism

c. Pentose Phosphate Pathway

d. Glycolysis

Answer 1

Answer:

a. Galactose metabolism

Explanation:

UDP is also also required for the galactose metabolism. The main pathway of the galactose metabolism is a two-part process in which conversion of the β-D-galactose to  to UDP-glucose takes place.  

In the initial stage, conversion of the β-D-galactose to the α-D-galactose which is catalyzed by the mutarotase enzyme.  

The next pathway is the conversion of α-D-galactose to the UDP-glucose by using the three principal enzymes which are:  

• The first enzyme is the galactokinase (GALK) which phosphorylates α-D-galactose to the galactose-1-phosphate.
• The second enzyme is the Galactose-1-phosphate uridyltransferase which contributes in the transfer of a UMP group abstracted from UDP-glucose to the galactose-1-phosphate and formation of UDP-galactose takes place.
• The third enzyme is the UDP galactose-4’-epimerase which helps in the interconvertion of the UDP-galactose and the UDP-glucose.