ACBS 445 EXAM 2 QUESTIONS AND
CORRECT ANSWERS
What is the function of the Cori cycle? What organs are involved? - Answer-Red blood
cells and liver are both involved the Cori cycle where the purpose of the Cori cycle is
recycle lactate into glucose to help prevent lactic acidosis.
Be able to explain why the conversion of glyceraldehyde 3P to 1,3 BP glycerate can
force the production of lactate in tissues that lack oxygen - Answer-The conversion
generates NADH, needed to reduce pyruvate to lactate in anaerobic conditions.
Be able to explain why the conversion of glyceraldehyde 3P to 1,3, BP glycerate forces
the production of lactate in tissues that lack mitochondria - Answer-Without
mitochondria, NADH cannot be oxidized, necessitating lactate production.
Explain how glucose transporters affect flux of glucose amongst tissues - Answer-GLUT
proteins regulate glucose movement among tissues based on expression, insulin
sensitivity, and metabolic demands.
When do you mobilize glucose stored as glycogen in liver? In skeletal muscle? Why for
each? - Answer-Glucose stored in the liver as glycogen is mobilized during fasting to
maintain blood glucose levels. In skeletal muscle, glycogen is mobilized during exercise
to provide energy for muscle contraction. This ensures a steady supply of glucose for
the body's energy needs during periods of increased demand.
From most efficient to least efficient please explain 3 ways to regenerate cytosolic
NAD+ and why they differ in efficiency. - Answer-Malate Aspartate Shuttle - Makes 2.5
ATP
Glycolysis Phosphate Shuttle (Lose 1 ATP)
Lactate Dehydrogenase (Makes NAD+)
Explain the passive transport of glucose into and out of the intestinal epithelial cell
(transporters in each end of the cell). Of these passive transporters which has a higher
Km for glucose, the transporter on the lumen surface or on the basolateral membrane
(membrane near blood vessel; logic this out)? What is the blood vessel that carries
glucose from the digestive tract called? (8pts) - Answer-Glucose moves in and out of
the intestinal epithelial cell passively through transporters on both sides of the cell, a
transporter on the lumen surface and a transporter on the basolateral membrane. These
CORRECT ANSWERS
What is the function of the Cori cycle? What organs are involved? - Answer-Red blood
cells and liver are both involved the Cori cycle where the purpose of the Cori cycle is
recycle lactate into glucose to help prevent lactic acidosis.
Be able to explain why the conversion of glyceraldehyde 3P to 1,3 BP glycerate can
force the production of lactate in tissues that lack oxygen - Answer-The conversion
generates NADH, needed to reduce pyruvate to lactate in anaerobic conditions.
Be able to explain why the conversion of glyceraldehyde 3P to 1,3, BP glycerate forces
the production of lactate in tissues that lack mitochondria - Answer-Without
mitochondria, NADH cannot be oxidized, necessitating lactate production.
Explain how glucose transporters affect flux of glucose amongst tissues - Answer-GLUT
proteins regulate glucose movement among tissues based on expression, insulin
sensitivity, and metabolic demands.
When do you mobilize glucose stored as glycogen in liver? In skeletal muscle? Why for
each? - Answer-Glucose stored in the liver as glycogen is mobilized during fasting to
maintain blood glucose levels. In skeletal muscle, glycogen is mobilized during exercise
to provide energy for muscle contraction. This ensures a steady supply of glucose for
the body's energy needs during periods of increased demand.
From most efficient to least efficient please explain 3 ways to regenerate cytosolic
NAD+ and why they differ in efficiency. - Answer-Malate Aspartate Shuttle - Makes 2.5
ATP
Glycolysis Phosphate Shuttle (Lose 1 ATP)
Lactate Dehydrogenase (Makes NAD+)
Explain the passive transport of glucose into and out of the intestinal epithelial cell
(transporters in each end of the cell). Of these passive transporters which has a higher
Km for glucose, the transporter on the lumen surface or on the basolateral membrane
(membrane near blood vessel; logic this out)? What is the blood vessel that carries
glucose from the digestive tract called? (8pts) - Answer-Glucose moves in and out of
the intestinal epithelial cell passively through transporters on both sides of the cell, a
transporter on the lumen surface and a transporter on the basolateral membrane. These
