Gluconeogenesis, The Pentose Phosphate Pathway, And Glycogen Metabolism

Front 1

True or False: In contrast to glycolysis, the pentose phosphate pathway allows the complete oxidation of glucose to CO2.

Back 1

True

Front 2

True or False: The formation of DNA and RNA directly depends on high gluconeogenesis activity in the cell.

Back 2

False

Front 3

True or False: Glucose 1-phosphate is the direct product of glycogenolysis.

Back 3

True

Front 4

True or False: Glycogen synthase catalyzes the linkage of all glucose molecules used in the formation of glycogen in the liver and muscle tissue.

Back 4

False

Front 5

True or False: Glycogen synthase catalyzes the joining of two glucose units, supplied as UDP-glucose, to initiate formation of a glycogen chain.

Back 5

False

Front 6

True or False: Gluconeogenesis is simply a reversal of glycolysis that occurs when blood glucose levels fall below normal.

Back 6

False

Front 7

True or False: The formation of one mole of glucose by gluconeogenesis from pyruvate requires the same amount of energy as that produced by glycolytic degradation of one mole of glucose to pyruvate.

Back 7

False

Front 8

True or False: The Cori cycle is a combination of glycolysis and gluconeogenesis occurring in different body tissues.

Back 8

True

Front 9

True or False: The enzymes that catalyze the reactions of the pentose phosphate pathway are all found in the cytosol.

Back 9

True

Front 10

True or False: The enzymes photofructokinase-1 and fructose 1,6-bisphosphatase form a substrate cycle.

Back 10

True

Front 11

True or False: Normally, the brain relies almost entirely on glucose for its energy needs.

Back 11

True

Front 12

True or False: Most glucose 6-phosphate produced in the liver from glycogenolysis is converted to free glucose for delivery to cells of other tissues.

Back 12

True

Front 13

True or False: Glucagon is a small peptide hormone that stimulates glycogenolysis by specifically targeting liver cells.

Back 13

True

Front 14

True or False: In the liver, glucagon causes the activation of phosphofructokinase-2 which produces fructose 2,6-bisphosphate, an activator of phosphofructokinase-1 and inhibitor of fructose 1,6-bisphosphate.

Back 14

False

Front 15

The coenzyme required for reductive biosynthesis (e.g., of fatty acids), that is produced by the pentose phosphate pathway, is ___

Back 15

NADPH

Front 16

The pentose phosphate pathway enzyme that catalyzes the transfer of a three-carbon unit from a ketose-phosphate to an aldose-phosphate is called a/an ___

Back 16

transaldolase

Front 17

Which pathway does pyruvate carboxylase belong to?

Back 17

gluconeogenesis

Front 18

Which pathway does ribose 5-phosphate belong to?

Back 18

pentose phosphate pathway

Front 19

Which pathway does glucose 6-phosphate belong to?

Back 19

gluconeogenesis or pentose phosphate pathway

Front 20

Which pathway does UDP-glucose belong to?

Back 20

glycogen synthesis

Front 21

Glycogen phosphorylase catalyzes the degradation of glycogen chains from their nonreducing ends, but stops four glucose resides from a branch point. The remaining molecule is called a/an ___

Back 21

limit dextrin

Front 22

Gluconeogenesis requires four enzymes that are not enzymes of the glycolytic pathway. These four enzymes are ___

Back 22

pyruvate carboxylase
phosphoenolpyruvate carboxykinase
fructose 1,6-bisphosphatase
glucose 6-phosphatase

Front 23

The protein that is attached to the glycogen primer required for glycogen synthesis is called ___

Back 23

glycogenin

Front 24

In mammals, the hormone ___ activates glycogen degradation in the muscles while ___ activates glycogen synthesis.

Back 24

epinephrine
insulin

Front 25

PEP carboxykinase is regulated by ___ of the gene in response to increased cAMP levels that result from prolonged release of glucagon.

Back 25

hormonal induction

Front 26

Three major gluconeogenic precursors are ___ which comes from anaerobic muscle, ___ which comes from the breakdown of protein in peripheral tissue, and ___ which comes from metabolism of triacylglycerols.

Back 26

lactate
alanine
glycerol

Front 27

A pair of reactions that both form and degrade a specific substrate, in order to fine tune regulation of metabolism, is called a ___

Back 27

substrate cycle

Front 28

The primary sites of gluconeogenesis in mammals is the ___ although small amounts of activity occur in ___ and ___.

Back 28

liver
kidney
small intestine