Question

1. In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate. Which of the following reasons provides the best chemical rationale for this transformation? Choose the best answer.

A. It is not possible to break a molecule of glucose into two pieces but it is possible to break a molecule of fructose into two pieces.

B. Glucose is not a high phosphotransfer potential molecule but fructose is a high phosphotransfer potential molecule.

C. There are no enzymes to add phosphate groups to glucose but there are enzymes to add phosphate groups to fructose.

D. If glucose were broken into two pieces the molecules would have unequal length but if fructose is broken into two pieces the molecules will have the same length.

2. Gluconeogenesis is _________________.

	A.	The exact opposite of glycolysis.
	B.	More energetically favorable than glycolysis.
	C.	Energetically more costly than glycolysis.
	D.	The amount of energy to perform gluconeogenesis is equal to the amount of energy in metabolizing glucose.

3. In the citric acid cycle, the acetyl-coA is linked to a pre-existing molecule of_______________.

	A.	citrate (citric acid)
	B.	oxaloacetate
	C.	fumarate
	D.	succinate
	E.	pyruvate

Answer 1

1. B. Glucose is not a high phosphotransfer potential molecule but fructose is a high phosphotransfer potential molecule.

In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate because glucose is not a high phosphotransfer potential molecule but fructose is a high phosphotransfer potential molecule.

2. C. is energetically more costly than glycolysis

Glycolysis is energetically favourable than gluconeogenesis

3. b. oxaloacetate

In the citric acid cycle, the acetyl-coA is linked to a pre-existing molecule of oxaloacetate