Deck 17: Gluconeogenesis

Question 1

In spirit, gluconeogenesis is the reversal of glycolysis ________________ (true or false).

Answer 1

False

Question 2

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
____________: This essential nutrient is required for the carboxylation of pyruvate in humans.

Answer 2

l

Question 3

Some amino acids are converted to glucose via conversion to pyruvate and ________________.

Answer 3

oxaloacetate

Question 4

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The compound ____________ activates glycolysis and inhibits gluconeogenesis via conversion of fructose 1,6-bisphosphate.

Question 5

The daily glucose requirement for a typical adult brain is ________________.

Question 6

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The ____________ cycle is responsible for converting muscle lactate into glucose in the liver.

Question 7

Glycerol from fats is modified first by glycerol kinase and then a second enzyme to enter gluconeogenesis at the intermediate ________________.

Question 8

The enzyme that carboxylates pyruvate is oxaloacetate is __________________.

Question 9

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The process by which noncarbohydrate precursor molecules are converted into glucose is ____________.

Question 10

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The stores of glucose are enough to support metabolism of a person for ____________.

Question 11

The process of forming glucose from amino acids is called ________________.

Question 12

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The reaction that uses GTP and not ATP as its high-phosphoryl-transfer potential donor is ____________.

Question 13

The gluconeogenesis step responsible for reversing pyruvate kinase is ________________.

Question 14

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
____________ controls the synthesis and degradation of fructose 2,6-bisphosphate.

Question 15

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
____________: An intermediate that is decarboxylated and phosphorylated to produce phosphoenolpyruvate.

Question 16

ATP in the reaction catalyzed by PEPCK is used to fix ________________ to biotin.

Question 17

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The conversion of glucose 6-phosphate to glucose takes place in the ____________.

Question 18

The amount of glucose in the bloodstream and other body fluids is ________________.

Question 19

The cellular compartment where the first step in gluconeogenesis occurs is _______________.

Question 20

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
a) liver
b) muscle
c) one day
d) endoplasmic reticulum
e) gluconeogenesis
f) phosphoenolpyruvate carboxykinase
g) PFK2
h) Cori
i) fructose 2,6-bisphosphate
j) magnesium
k) oxaloacetate
l) biotin
m) 2 hours
n) ATP
The major tissue in which gluconeogenesis takes place is the ____________.

Question 21

The ________________ cycle refers to the metabolic reactions by which glucose is converted into lactate in skeletal muscle, and then lactate is converted back into glucose in the liver.

Question 22

Biotin provides ________________ for the pyruvate carboxylase reaction.

A) a long flexible arm for the active-site location of substrate
B) carboxylation of pyruvate
C) group transfer from one site of the enzyme to another
D) All of the above.
E) None of the above.

Question 23

Hormones that activate PKA ________________ the flux of carbon to glucose.

Question 24

The primary raw materials for gluconeogenesis are:

A) galactose and sucrose.
B) pyruvate and oxaloacetate.
C) lactate and amino acids.
D) fructose and glycerol.
E) lactose and lactate.

Question 25

The first step in gluconeogenesis is the ________________ of pyruvate to form oxaloacetate.

Question 26

Hormonal activation of cyclic AMP levels:

A) activates protein kinase A phosphorylation of FBPase2.
B) phosphorylates PFK2 on a tyrosine residue.
C) leads to the activation of PFK.
D) activates the PKC phosphorylation of PFK2.
E) increases the activation of gluconeogenesis.

Question 27

Which of the following statements about PFK is correct?

A) AMP and ADP both bind to and stabilize the inactive conformation of F6-P.
B) ATP can overcome the inhibition by citrate.
C) Citrate is an inhibitor of PFK.
D) Acidic conditions from anaerobic metabolism activate PFK.
E) None of the above.

Question 28

The phosphoryl donor in the formation of phosphoenolpyruvate is:

A) pyruvate.
B) PEP.
C) ATP.
D) GTP.
E) inorganic phosphate.

Question 29

Adenosine monophosphate will have a(n) ________________ on PFK and a(n) ________________ effect on fructose 1,6-bisphosphatase.

Question 30

The major site for gluconeogenesis is in which of the following tissues?

A) the brain
B) the liver
C) striated muscle
D) adipose
E) red blood cells

Question 31

Lactate produced in muscle tissue is converted to ________________ by ________________.

A) glucose / gluconeogenesis
B) lactate / the Cori cycle
C) glucose / the Cori cycle
D) pyruvate / glycolysis
E) ATP : the Krebs cycle

Question 32

The bifunctional enzyme is also known as:

A) phosphofructokinase I.
B) phosphofructokinase II.
C) fructose-1,6 phosphatase.
D) protein kinase 2.
E) phosphoenolpyruvate carboxykinase.

Question 33

In general, the liver:

A) does not utilize glucose under starvation/low-energy conditions.
B) acts as a glucose buffer for the rest of the body.
C) is a producer of glucose for the body under low-energy conditions.
D) All of the above.
E) None of the above.

Question 34

Transport of oxaloacetate produced by PEPCK utilizes the mitochondrial and cytosolic enzyme ________________.

Question 35

The enzymes involved in shuttling carbons involved in gluconeogenesis from the mitochondria to the cytosol are called:

A) malate dehydrogenase.
B) citrate synthase.
C) oxaloacetate transferase.
D) oxaloacetate reductase.
E) None of the above.

Question 36

Glucose 6-phosphatase takes place in which cellular location?

A) the cytoplasm
B) the endoplasmic reticulum
C) the mitochondria
D) the nucleus
E) the plasma membrane

Question 37

High blood sugar after a meal ________________ the level of insulin released by the pancreas.

A) increases
B) decreases
C) has no effect on
D) chronically activates
E) chronically inhibits

Question 38

How many high-energy phosphate bonds are expended in gluconeogenesis?

A) three
B) six
C) two
D) four
E) one

Question 39

High levels of ATP and citrate:

A) indicate a high-energy-well-fed state.
B) promote gluconeogenesis.
C) inhibit glycolysis.
D) All of the above.
E) None of the above.

Question 40

Insulin resistance is a hallmark of:

A) PEPCK activation
B) pancreatic disorder
C) Type 1 diabetes
D) Type 2 diabetes
E) long-term starvation

Question 41

What would be the result of this on a person's blood-sugar level?

Question 42

What is the role biotin has in pyruvate carboxylase catalytic mechanism?

Question 43

What are the key glycolytic enzymes and why are they considered key? How are these steps overcome in gluconeogenesis?

Question 44

What might help bring this about?

Question 45

How are gluconeogenesis and glycolysis coordinated by nucleotides?

Question 46

How does the liver restore the level of glucose for active muscles?

Question 47

In this light, how can gluconeogenesis continue?

Question 48

How are gluconeogenesis and glycolysis regulated reciprocally?

Question 49

Which metabolic steps differ from glycolysis in gluconeogenesis?

Question 50

Explain how fructose 2,6-bisphosphate (F-2,6-BP) levels are regulated in the cell, and the relationship between F-2,6-BP levels and blood glucose levels.