This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: nutrition and digestion, Subject name: Biochemistry
[{'content': 'In starvation, glucose is mainly utilized as metabolic fuel by \nSelect and explain. \nA. Erythrocytes, B. Liver, C. Kidney, D. Skeletal muscle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In the fasting state, as the concentration of glucose in the poal blood coming from the small intestine falls, insulin secretion decreases, and skeletal muscle and adipose tissue take up less glucose. The increase in secretion of glucagon by a cells of the pancreas inhibits glycogen synthetase and activates glycogen phosphorylase in the liver leading to glycogenolysis. The resulting glucose-6-phosphate is hydrolyzed by glucose 6-phosphatase, and glucose is released into the bloodstream for use by the brain and erythrocytes. Reference: Harper; 30th edition; Chapter 14; Page no: 148', 'role': 'assistant'}]