This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemistry of Carbohydrates, Amino sugars, and Mucopolysaccharides, Subject name: Biochemistry
Insulin mediated uptake of glucose into muscle is through? 
Select and explain. 
A. GLUT 2, B. GLUT 4, C. GLUT l, D. GLUT 3
B: GLUT 4
Answer: B: GLUT 4 
Explanation: Ref: Harper's illustrated Biochemistry, 28th ed, chapter 20, pp-171.Explanation:TransporterLocated inPropertiesGluT1RBC, brain, kidney, colon, retina, placentaGlucose uptake in most of the cellsGluT2Intestinal cells (serosal surface), liver, beta cells of pancreasLow affinity, Glucose uptake in the liver, glucose sensor in beta cellsGluT3Neurons, brainHigh affinity. Glucose into brain cellsGluT4Skeletal & heart Muscle, adipose tissueInsulin mediated glucose uptakeGluT5Small intestine, testis, sperms, kidneyFructose transporter, poor ability transport glucoseGluT6------Nonfunctional proteinGluT7Liver endoplasmic reticulumGlucose from ER to cytoplasm