This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Biochemistry
Which of the following enzyme is absent in muscle ? 
Select and explain. 
A. Glucose-1-phosphatase, B. Glucose-6-phosphatase, C. Glycogen phosphorylase, D. Thiophorase
B: Glucose-6-phosphatase
Answer: B: Glucose-6-phosphatase 
Explanation: Skeletal muscle and adipose tissue cannot contribute directly to blood glucose because it does not contain glucose-6-phosphatase.The glucose -1-phosphate is conveed to glucose-6-phosphate by phosphoglucomutase. And only liver but not muscle can utilize glucose-6-phosphate to generate glucose