Lecture 21 (Exam 2)

Question 1

Maintaining levels of glucose is important because the _______ depends on glucose as its primary fuel and _______ use glucose as their only fuel.

Answer 1

Brain

RBCs

Question 2

Whole body needs ______ glucose per day.

Answer 2

160 g

Question 3

Daily glucose requirement of the brain is…

Answer 3

120 g

Question 4

Glucose present in the body fluids is…

Answer 4

20 g

Question 5

Glucose that is readily available from glycogen is…

Answer 5

190 g

Question 6

Direct glucose reserves sufficient to meet glucose needs for about a day. _________ is especially important during a longer period of fasting and starvation.

Answer 6

Gluconeogenesis

Question 7

Gluconeogenesis occurs where?

Answer 7

Liver and kidney

Question 8

The synthesis of glucose can occur from non-carbohydrate precursors (through gluconeogenesis). These precursors are…

Answer 8

Lactate
Amino acids
Glycerol

Question 9

Gluconeogenesis by-passes the irreversible steps of glycolysis through four enzymes, which are…

Answer 9

Pyruvate carboxylase
Phosphoenolpyruvate carboxykinase
Fructose 1,6-bisphosphatase
Glucose 6-phosphatase

Question 10

Pyruvate carboxylase is a _________ enzyme. Other enzymes of gluconeogenesis are found in the ________.

Answer 10

Mitochondrial

Cytoplasm

Question 11

Oxaloacetate (OAA), product of PC, is transported to the cytoplasm via ________ shuttle.

Answer 11

Malate

Question 12

Free glucose can leave the _______ and enter the ______.

Answer 12

Liver

Blood

Question 13

This is an enzyme located in the lumen of the endoplasmic reticulum (ER).

Answer 13

Glucose 6-phosphatase

Question 14

A protein called _____ transports Glucose 6-phsophatase to the ER.

Answer 14

T1

Question 15

A protein called ______ transports inorganic phosphate (from glucose 6-phosphatase) back into the cytosol.

Answer 15

T2

Question 16

A protein called ______ transports glucose back to the cytoplasm.

Answer 16

T3

Question 17

Glycolysis generates ______, gluconeogenesis consumes ______.

Answer 17

ATP

ATP

Question 18

In the liver, rates of glycolysis and gluconeogenesis are adjusted to maintain _______ glucose.

Answer 18

Blood

Question 19

Fructose 2,6-bisphosphate strongly stimulates __________ (gluconeogenesis) and inhibits fructose 1,6-bisphosphatase (glycolysis).

Answer 19

Phosphofructokinase

Question 20

Two enzymes regulate the concentration of fructose 2,6-bisphosphate, which are…

Answer 20

Phosphofructokinase 2 (PFK2)
Fructose bisphosphatase 2 (FBPase2)

Question 21

In the Cori Cycle, ________ produced in skeletal muscle and red blood cells can be converted back to pyruvate in the liver. The pyruvate can enter the gluconeogenic pathway and regenerate glucose (which was the source of the ________).

Answer 21

Lactate

Lactate