Comprehensive Diabetes Mellitus and Glucose Metabolism Mastery Examination: Glycolysis Glycogenesis Glycogenolysis and Gluconeogenesis Pathways, Insulin and Glucagon Physiology, GLUT Transporter Regulation, Incretin and DPP-4 Mechanisms, C-Peptide and Amy

Comprehensive Diabetes Mellitus and Glucose Metabolism Mastery Examination: Glycolysis Glycogenesis Glycogenolysis and Gluconeogenesis Pathways, Insulin and Glucagon Physiology, GLUT Transporter Regulation, Incretin and DPP-4 Mechanisms, C-Peptide and Amylin Function, Type 1 and Type 2 Diabetes Pathophysiology, Insulin Resistance and Beta-Cell Failure, Hyperglycemia and Hypoglycemia Disorders, Dawn and Somogyi Phenomena, Diabetic Ketoacidosis and Hyperosmolar Syndrome, Macrovascular and Microvascular Complications, Glycemic Index and HbA1c Targets, Pharmacologic Therapies Including Insulin Analogues, Sulfonylureas Biguanides GLP-1 Agonists and SGLT-2 Inhibitors Exam Questions Verified and Complete Rationales Latest Updated 2026 What is glycolysis? Breakdown of glucose; humans primarily rely on glucose and fats to provide energy for cellular function What is glycogenesis? excess glucose is stored in the form of glycogen, especially in muscle and liver cells What is glycogenolysis? breakdown of glycogen to glucose What is gluconeogenesis? endogenous production from amino acids, glycerol, lactate, and other metabolic intermediates by the liver What is the function of the GLUT protein system? GLUT 1-4: cells vary in permeability to glucose; most cells use process of facilitated diffusion which utilizes four glucose transporter proteins Which GLUT proteins are insulin dependent? GLUT-4 Which GLUT proteins are insulin independent? GLUT-1,2,3 Where are GLUT-1 and GLUT-3 located? (3) - Neural cells - RBCs - Pancreatic beta cells Where is GLUT-2 proteins located? liver cells Where are GLUT-4 proteins located? (2) - Cardiac and skeletal muscle cells - Adipose cells What is C-peptide? correlates with level of insulin production How is C-peptide a diagnostic tool for Type 1 versus Type 2 diabetes? There is less C-peptide in Type 1 What is the role of amylin? (4) - co-secreted with insulin from the pancreas - targets α-cells in pancreas decrease glucagon secretion - delays GI emptying to prevent postprandial blood sugar spikes - promotes satiety Where is amylin produced? pancreas What is the role of glucagon in glucose metabolism? (2) - produced by α-cells in pancreas and secreted as plasma glucose levels drop - targets the liver → stimulates breakdown of stored glycogen and use of FFA & amino acids to form glucose → increase blood glucose level Where is glucagon produced? alpha cells of pancreas What is the role of incretins (GLP-1) in glucose metabolism? (2) - targets the pancreas → increase insulin secretion and decrease glucagon secretion - delays GI emptying → promotes satiety Where is incretin (GLP-1) produced? cells in the small intestine How is DPP-4 related to incretin level? GLP-1 has a very short half-life in circulation; rapidly degraded by enzyme DPP-4 What is the role of neuropeptide Y (NPY) in metabolism? creates "hunger" sensation in hypothalamus → increased food intake → weight gain/obesity risk Where is NPY produced? hypothalamus What is the role of ghrelin in metabolism? ghrelin levels increase during dieting, and it is ectopically expressed by metastatic cancer cells → promotes hypermetabolic state Where is ghrelin produced? secreted by cells in the stomach and targets hypothalamus to secrete NPY What is the role of leptin in metabolism? (2) - inhibits secretion of NPY promoting satiety - increases metabolism Where is leptin produced? adipose tissue How does growth hormone (GH) contribute to hyperglycemia? promotes synthesis of IGF How does cortisol and catecholamines (stress hormones) contribute to hyperglycemia? ↑ production and release of glucose from the liver How does catecholamines (epinephrine) contribute to hyperglycemia? ↑ production and release of FFA What are 4 examples of screening methods