Quiz on Glucose Metabolism

In which forms is glucose primarily stored in living organisms?

• Starch in animals, glycogen in plants

• Starch in plants, glycogen in animals

• Cellulose in animals, glycogen in plants

• Cellulose in plants, starch in animals

What is the net yield of ATP molecules from one molecule of glucose during glycolysis, and what other energy-carrying molecule is produced?

• 4 ATP and 2 FADH₂

• 2 ATP and 2 FADH₂

• 4 ATP and 2 NADH

• 2 ATP and 2 NADH

How does a high concentration of ADP affect the activity of phosphofructokinase (PFK), and what is the significance of this?

• It inhibits PFK, slowing down glycolysis because energy is plentiful

• It has no effect on PFK activity

• It activates PFK, speeding up glycolysis because more ATP is needed

• It activates PFK, slowing down glycolysis because energy is plentiful

After glycolysis, what are the three primary metabolic fates of pyruvate?

• Conversion to glucose, fatty acids, and amino acids

• Conversion to glycogen, lactate, and acetyl-CoA

• Conversion to lactate, acetyl-CoA, or oxaloacetate

• Conversion to ethanol, CO2, and glucose-6-phosphate

How many ATP molecules are consumed during the production of one molecule of glucose by gluconeogenesis?

• 2

• 4

• 6

• 8

Which of the following is NOT a unique enzyme used in gluconeogenesis to bypass the irreversible steps of glycolysis?

• Pyruvate carboxylase

• Phosphoenolpyruvate carboxykinase

• Fructose bisphosphatase

• Phosphofructokinase

What is the immediate precursor to glycogen in glycogen synthesis, and what molecule is required to generate it?

• Glucose-6-phosphate; ATP

• Glucose-1-phosphate; ATP

• Glucose; UTP

• UDP-glucose; UTP

How does glycogenolysis differ from glycogen synthesis, and what is the primary product released by the breakdown of glycogen?

• Glycogenolysis involves hydrolysis, releasing glucose

• Glycogenolysis uses UDP-glucose, releasing glucose-1-phosphate

• Glycogenolysis involves phosphorolysis, releasing glucose-1-phosphate

• Glycogenolysis uses UTP, releasing glucose-6-phosphate

What are the two main products of the pentose phosphate pathway (PPP) and what are their primary functions in the cell?

• NADH and ribose-5-phosphate for energy production and DNA synthesis

• NADPH and ribose-5-phosphate for reducing power and DNA synthesis

• ATP and NADPH for energy production and reducing power

• FADH₂ and ribose-5-phosphate for energy production and DNA synthesis

How does the primary metabolic pathway of fructose in the liver differ from that of glucose, and what could be a potential consequence of this difference?

• Fructose enters glycolysis at the same step as glucose, leading to increased ATP production

• Fructose enters glycolysis at a different step, bypassing a key regulatory point which may contribute to fat buildup

• Fructose is not metabolised in the liver, leading to increased blood glucose levels

• Fructose is converted to glycogen, leading to decreased fat buildup