Question

Insulin is released frompancreatic b cellswhen blood glucose levels increase and glucagon isreleased from pancreatic a cells when blood glucose levelsdecrease. Blood glucose concentration is tightly controlled and atthe basic level it appears that glucose binds toGLUT2 receptors on b cells increasing the concentrationof ATP because of the increased concentration of glucose in thesecells. The increase in ATP decreases potassium concentrations and calcium channels are opened leading toinsulin secretion. There are, however, a number of otherinsulin/glucagon regulators such as amino acids,catecholamines, insulin, neurotransmitters and free fattyacids. Consequently the search for causes of obesity requirescareful focus and much of current research focuses on GProtein Coupled Receptors.Which of thefollowing is not of special interest to those studying GPCR andtheir involvement in diabetes andobesity?

a. allelic (SNP)differences in the extracellular domain of GPCRs between obese andcontrols

b. classes ofGPCRs found in target tissues thought to be associated withobesity

c.a subunits associated withG proteins in tissues thought to be associated withobesity

d. the role ofuncoupling mitochondrial membrane proteins in targettissues

e. the binding ofmolecules other than glucose to GPCRs on target tissues