This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
UDP Glucose is formed from 
Select and explain. 
A. Glucose-1-phosphate, B. Glycogen, C. Lactose phosphate, D. Starch
A: Glucose-1-phosphate
Answer: A: Glucose-1-phosphate 
Explanation: UDP glucose is formed from glucose-1-phosphate and UTP (uridine triphosphate) by the enzyme UDP-glucose pyrophosphorylase.
Reference: Vasudevan 7th  ed, pg 125