Endocrine System & Diabetes Quiz

Question 1

• A patient with type 1 diabetes, who takes insulin before eating dinner, skips dinner.
• Three hours later, the patient experiences shaky, sweaty, and confused symptoms.
• The symptoms are due to low blood glucose levels (hypoglycemia) resulting from the increased release of glucagon which is a hormone that raises blood glucose levels.

Question 2

• A patient with severe hyperglycemia (high blood glucose levels) has fallen unconscious.
• The appropriate action to reverse the effect is to give insulin, a hormone that lowers blood glucose levels.

Question 3

• Caffeine is a potent inhibitor of cAMP phosphodiesterase.
• Drinking two cups of strong espresso would result in a prolonged response to glucagon in the liver, due to an inhibition of the enzyme PKA.

Question 4

• Increased blood glucose levels (from 5 to 10 mM) trigger insulin release by the pancreas.
• A mutation in pancreatic glucokinase leads to MODY (maturity-onset diabetes of the young) due to a reduced ability to raise ATP levels within the pancreatic beta cells .

Question 5

• The organ with the highest glucose demand for fuel is the brain.

Question 6

• Glucagon release does not affect muscle metabolism because muscle cells lack the glucagon receptor.

Question 7

• Tremors, sweating, and rapid heartbeat caused by low blood sugar (hypoglycemia) are symptoms of the release of the hormone epinephrine.

Question 8

• A high-carbohydrate meal leads to the lowest level of circulating glucagon shortly after eating.

Question 9

• To determine if a patient with severe hyperglycemia has type 1 or type 2 diabetes, measure the C-peptide levels.

Question 10

• High blood glucose levels in the urine, as well as in the blood, can lead to cerebral dysfunction due to dehydration.

Question 1

• The main transporter responsible for fructose uptake from the blood into cells is GLUT5.

Question 2

• A patient with alcoholism and pancreatitis experiencing discomfort after a high-carbohydrate meal likely has a reduced ability to digest starch.

Question 3

• A man with type 1 diabetes who neglects insulin injections will have the greatest effect on muscle cells.

Question 4

• Digestion of a flour, milk, and sucrose-containing cake primarily yields glucose, fructose, and galactose.

Question 5

• A patient with a genetic defect in intestinal disaccharidase activity will have higher levels of Maltose, sucrose, and lactose in the stool after consuming oatmeal and milk with table sugar.

Question 6

• Amylopectin is a carbohydrate made of glucose units linked through a-1,6 glycosidic bonds.

Question 7

• Increased dietary fiber intake can cause abdominal cramping, bloating, and flatulence due to bacterial fermentation of fibers in the colon producing gases like methane and hydrogen.

Question 8

• A patient with diabetes who avoids table sugar but consumes fruits, fruit drinks, milk, honey, and vegetables is primarily consuming glucose.

Question 9

• A 10-year-old patient experiencing nausea, abdominal pain, and flatulence after drinking milk likely has lactose intolerance and should avoid milk products.

Question 10

• A runner seeking a high-glycemic index food for carbohydrate loading should choose ice cream or malted milk balls.

Question 1

• The major role of glycolysis is to produce energy.

Question 2

• The net yield of ATP and NADH from glyceraldehyde 3-P to pyruvate in glycolysis is 2 ATP and 2 NADH

Question 3

• The net ATP and NADH production from glycolysis, starting with glucose 1-P and ending with two pyruvate molecules is 2 ATP and 2 NADH.

Question 4

• Glycolysis is the pathway used by all cells for energy production; ATP is formed by substrate- level phosphorylation in the beginning of glycolysis.

Question 5

• Fructose 1,6-bisphosphate is a substrate found in both the fructose metabolic pathway and the glycolytic pathway.

Question 6

• A 4-week-old infant with frequent vomiting, abdominal tenderness, enlarged liver, and potential cataracts, with a positive urine dipstick test for a reducing sugar and slightly low blood glucose likely has galactosemia.

Question 7

• Measurement of galactose 1-phosphate would diagnose the enzyme deficiency in a patient with galactosemia.

Question 8

• Metformin decreases hepatic gluconeogenesis, theoretically avoiding lactic acidosis, because the Cori cycle overcomes lactate buildup in the liver.

Question 9

• A neonate with severe acidosis and a mutation in the E1 subunit of pyruvate dehydrogenase will have increased plasma lactate and pyruvate concentrations.

Question 10

• Pyruvate carboxylase deficiency leads to lactic acidosis due to an accumulation of acetyl-CoA in the mitochondria.

Question 1

• The component of the electron transport chain in an oxidized state after cyanide is added to mitochondria incubated with malate and valinomycin is Complex III.

Question 2

• Valinomycin increases potassium ion permeability, reducing the proton motive force (PMF) to zero.

Question 3

• Dinitrophenol inhibits/uncouples oxidative phosphorylation by allowing proton exchange across the inner mitochondrial membrane, inhibiting the generation of ATP.

Question 4

• Iron deficiency anemia causes fatigue as Fe-S centers are vital for electron transfer in the electron transport chain.

Question 5

• A patient with OXPHOS disease would exhibit a high NADH:NAD+ ratio in the mitochondria.

Question 6

• Hemoglobin and myoglobin, not complex III or IV, would not be affected by reduced heme synthesis. (Important note: complex III and IV use iron as a component).

Question 7

• Rotenone inhibits NADH dehydrogenase; this would result in a 95% reduction in ATP production in mitochondria (if the rotenone could be absorbed by the mitochondria which may not happen).

Question 8

• Oxidative phosphorylation's main component is ATP synthase, producing ATP by using a source of electrons (usually oxygen).

Question 9

• If a high salt solution disrupts noncovalent interactions in mitochondria, Complex III is lost because it is a component of the electron transfer chain.

Question 10

• An increase in body temperature might be a side effect of a drug that activates uncoupling proteins (UCPs).

Question 1

• Free radicals are neutralized using enzymes like Superoxide dismutase.

Question 2

• Superoxide dismutase catalyzes the conversion of two superoxide radicals into hydrogen peroxide and oxygen.

Question 3

• Vitamin E is an antioxidant that stabilizes free radicals by forming a covalent bond with them.

Question 4

• Iron is the metal that, when present, catalyzes the conversion of hydrogen peroxide to reactive radical forms.

Question 5

• Oxidative damage is higher in mitochondrial DNA because the mitochondrial membrane is permeable to ROS (reactive oxygen species), unlike the nucleus.

Question 6

• Chronic granulomatous disease is characterized by the inability to produce superoxide and/or hydrogen peroxide.

Question 7

• Amyotrophic lateral sclerosis (ALS) is a disease related to the inability to detoxify oxidized glutathione.

Question 8

• High concentrations of nitric oxide can produce Reactive Nitrogen-Oxygen Species (RNOS), leading to ischemic heart disease, infertility, and certain infections.

Question 9

• Foreign chemicals like alcohol and medications increase the risk of free-radical injury by inducing cytochrome P450 enzymes or oxidizing enzymes in peroxisomes.

Question 10

• Citrus fruits have high levels of antioxidants.

Question 1

• Under conditions of glucagon release, liver glycogen degradation produces more glucose 1-phosphate than glucose.

Question 2

• A patient with glycogen deposits and shorter-than-normal branches after an overnight fast likely has a defect in glycogen phosphorylase activity.

Question 3

• A patient with muscle phosphorylase deficiency will exhibit symptoms of exercise fatigue more quickly, elevated lactate levels, and lower glycogen stores in the forearm muscle compared to normal individuals during exercise.

Question 4

• An individual in a glucose tolerance test (with a normal response to glucose intake) will have enhanced glycogen synthase activity in the liver.

Question 5

• Liver (hepatic) glycogen breakdown when insulin is needed would be in a state of high levels of intracellular calcium.