Exam 2 review

How are monosaccharides like glucose and fructose from the diet processed in the body?

• They are degraded enzymatically before absorption via Glycosidases.

• They are absorbed directly through intestinal and kidney membranes without enzymatic degradation.

• They are converted to polysaccharides before absorption via Amylases.

• They are stored in the stomach before being transported into the bloodstream.

Which of the following tissues primarily use the insulin-dependent glucose transporter, GLUT-4?

• Liver and Brain

• Small Intestine and Pancreas

• Red Blood Cells and Kidney

• Skeletal Muscle and Adipose Tissue

What is the incretin effect in the context of oral glucose administration?

• The effect where oral glucose administration results in a greater insulin secretion than intravenous glucose administration.

• The effect where glucose is absorbed faster when administered orally compared to intravenously

• The effect where glucose levels rise more slowly after oral glucose administration compared to intravenous glucose administration.

• The effect where oral glucose administration leads to the suppression of glucagon secretion

Which of the following best describes the role of phosphofructokinase-1 (PFK-1) in glycolysis?

• It catalyzes the conversion of glucose to glucose-6-phosphate.

• It catalyzes an irreversible step that converts fructose-6-phosphate to fructose-1,6-bisphosphate.

• It converts phosphoenolpyruvate (PEP) to pyruvate.

• It degrades fructose-1,6-bisphosphate back to fructose-6-phosphate.

How many molecules of each product are generated from one molecule of glucose during glycolysis?

• 1 pyruvate, 1 ATP, 1 NADH

• 2 pyruvate, 4 ATP (net), 2 NADH

• 2 pyruvate, 2 ATP (net), 2 NADH

• 2 pyruvate, 2 ATP (net), 4 NADH

Under which of the following conditions is glycolysis most likely to be activated?

• Low ATP, high AMP

• High ATP, low AMP

• High ATP, high NADH

• Low AMP, high ATP

What effect does an increase in blood glucose have on hexokinase in red blood cells?

• It decreases the activity of hexokinase to prevent excessive glucose consumption.

• It largely increases the activity of hexokinase to promote more glycolysis.

• It has little effect on hexokinase activity because it’s always saturated.

• It inhibits hexokinase to prevent glucose-6-phosphate accumulation.

Which of the following best describes the role of NADPH in reducing oxidative stress?

• NADPH directly neutralizes reactive oxygen species (ROS).

• NADPH provides reducing power to regenerate glutathione, which detoxifies reactive oxygen species.

• NADPH is used in glycolysis to generate ATP for antioxidant enzymes.

• NADPH inhibits the production of reactive oxygen species by mitochondria.

Which of the following conditions favor glycogenesis?

• High ATP, high glucose, and high insulin levels

• Low ATP, low glucose, and high glucagon levels

• High AMP, low glucose, and high epinephrine levels

• Low ATP, high NADH, and high acetyl-CoA levels

Which enzyme is responsible for adding the first 4-6 glucose residues during glycogen formation?

• Glycogen synthase

• Glucokinase

• Glycogenin

• Phosphoglucomutase