gluconeogenesis

gluconeogenesis

synthesis of glucose from non-carbohydrate precursors

pyruvate is converted to what?

oxaloacetate (OAA)

OAA forms _________________ via malate.

2-phosphoenol pyruvate

which steps in gluconeogenesis is involve in mitochondria?

steps 1 and 2

what is a prosthetic group, and carries the carbon dioxide necessary to convert pyruvate to oxaloacetate, serves as a carrier for the carbon dioxide

biotin

step 11 is what type of reaction in gluconeogenesis?

dephosphorylation reaction

fructose-2,6 bisphosphate _______ fructose 1,6-bisphosphatase

inhibits

t/f: enzyme PFK-1 is in glucneogenesis

false; it is replaced with fructose 1,6-bisphosphatase

what step is this in gluconeogenesis; fructose 6-phosphate is isomerized to glucose 6-phosphate and what is the enzyme?

step 12; enzyme is phosphoglucose isomerase

what step is this in gluconeogenesis; glucose 6-phosphate is dephosphorylated to D-glucose and what is the enzyme?

step 13; enzyme is glucose 6-phosphatase

the release of free glucose from glucose 6-phosphate occurs only in the _______ and ________.

liver; kidney

what does not occur in gluconeogenesis?

muscle because it lacks glucose 6-phosphate

gluconeogenesis is what type of process?

anabolic

what is used in gluconeogenesis?

4 ATP, 2 GTP, 2 NADH

what is the feedstock substrate for other cellular energy pathways?

pyruvate

what helps convert pyruvate to oxaloacetate; which is part of the TCA cycle

pyruvate carboxylase (enzyme)

what catalyzes conversion of pyruvate to acetyl CoA; the preparatory step in the TCA cycle?

pyruvate dehydrogenase

cori cycle

the combination of glucose transport to actively working tissues, and the reverse transport to lactate from those tissues back to the liver

glucose in the muscle is converted to lactate (anerobic glycolysis)

lactate diffuses to the blood and reaches the _________.

liver

lactate is converted to _________ in the liver. (gluconeogenesis)

glucose

glucose re-enter muscle and starts which pathway?

glycolysis

What is the essential compound required for carboxylation of pyruvate in humans?

a. biotin

b. oxaloacetate

c. glucose

d. calcium

e. alanine

a. biotin

Select all that apply. High levels of ATP and citrate:

a. activate glycolysis.

b. inhibit glycolysis.

c. favor gluconeogenesis.

d. inhibit gluconeogenesis

e. inhibit glycogenolysis

b. inhibit glycolysis.

c. favor gluconeogenesis

e. inhibit glycogenolysis

Choose the statement that sums up reciprocal regulation of gluconeogenesis and glycolysis.

a. When glucose is scarce, glycolysis will predominate.

b. When glucose is abundant, gluconeogenesis will predominate.

c. When glucose is abundant, glycolysis will predominate.

d. When glucose is abundant, glycolysis will be stopped.

e. When glucose is abundant, glycogenolysis will predominate.

c. When glucose is abundant, glycolysis will predominate.

What are the acceptable precursors of glucose for gluconeogenesis? Select all that apply.

a. glyceraldehyde

b. lactate

c. amino acids

d. glycogen

e. fatty acids

b. lactate

c. amino acids

e. fatty acids

Choose reaction that takes place in mitochondria.

a. phosphorylation of phosphofructokinase 2/ fructose bisphosphatase 2 by protein kinase A

b. formation of glucose from fructose 6-phosphate

c. activation of fructose 1,6-bisphosphatase by citrate

d. formation of oxaloacetate from pyruvate

e. formation of fructose 6-phosphate from fructose 1,6-bisphosphate

d. formation of oxaloacetate from pyruvate

In what form does oxaloacetate leave the mitochondrion?

a. succinate

b. malate

c. pyruvate

d. phosphoenolpyruvate

e. in unchanged form

b. malate

What organ controls the level of glucose in blood?

a. liver

b. kidneys

c. adipose tissue

d. nerve system

e. muscles

a. liver

Expression of what molecules is stimulated by glucagon?

a. fructose 2,6-bisphosphate and hexokinase

b. glucose 6-phosphate and pyruvate

c. glucose and pyruvate kinase

d. fructose 1,6-bisphosphate and phosphoenolpyruvate carboxykinase

e. fructose 6-phosphate and phosphofructokinase

d. fructose 1,6-bisphosphate and phosphoenolpyruvate carboxykinase

What molecule inhibits fructose 1,6-bisphosphatase?

a. fructose 6-phosphate

b. glucose

c. fructose 1,6-bisphosphate

d. glucose 6-phosphate

e. fructose 2,6-bisphosphate

e. fructose 2,6-bisphosphate

Gluconeogenesis often ends with the formation of glucose 6-phosphate in the muscle. Why does this happen?

a. Glucose 6-phosphate cannot convert into glucose because the reaction is energetically unfavorable.

b. Muscles lack phosphoglucokinase which is necessary to form glucose.

c. Glucose 6-phosphate is a stable compound and will not react further.

d. Glucose 6-phosphate is a toxic metabolite for muscle cells.

e. Muscles lack glucose 6-phosphatase which is necessary to form glucose.

e. Muscles lack glucose 6-phosphatase which is necessary to form glucose.