BIOL 304 Exam 4 Version A Questions

Which of the following enzymes is NOT involved in the breakdown of carbohydrates as part of glucose metabolism?

c) pepsin

The conversion of glucose 6-phosphate to fructose 6-phosphate is catalyzed by which enzyme in glycolysis?

b) phosphoglucoisomerase

What reaction does glyceraldehyde 3-phosphate dehydrogenase catalyze?

a) the conversion of glyceraldehyde 3-phosphate into 1,3-bisphosphoglycerate

At which step in glycolysis is ATP FIRST generated from ADP?

d) the conversion of 1,3 bisphosphate to 3-glycerate

What molecule would inhibit the activity of hexokinase?

b) glucose 6-phosphate

The conversion of dihydroxyacetone phosphate (DHAP) to glyceraldehyde 3-phosphate (GAP) is catalyzed by the enzyme?

b) triose phosphate isomerase

The net molecules of NADH made from each glucose that goes into glycolysis is:

b) 2

Glucose is phosphorylated in the cytoplasm to glucose 6-phospahte. This ensures that:

c) glucose 6-phosphate cannot enter a GLUT transporter

The tissue/organ mainly responsible for maintaining blood glucose levels is the:

d) liver

The processing of pyruvate through anaerobic fermentation that does NOT generate carbon dioxide is by conversion of pyruvate to:

c) lactate

Fructose in the liver can enter the glycolytic pathway through its conversion initially to?

a) fructose 1-phosphate

Which of the following enzymes is part of glycolysis and does NOT catalyze an essentially irreversible reaction?

c) phosphoglucoisomer

For pyruvate to enter into the pathway of gluconeogenesis, the molecule must first be converted to:

b) oxaloacetate

Which of the following hormones promotes glycolysis over gluconeogenesis?

d) insulin

The Cori cycle demonstrates that ____ produced by the muscles can be transported to the blood to the liver for conversion into ______.

b) lactate; glucose

Pyruvate carboxylase catalyzes the formation of oxaloacetate for gluconeogenesis. Which of the following conditions would allosterically inhibit this enzyme?

a) high levels of ADP

The key enzyme that kinks pyruvate to the citric acid cycle is:

a) pyruvate dehydrogenase

The first NADH that is generated by the citric acid cycle when acetyl CoA enter the cycle occurs when:

b) isocitrate is converted to alpha-ketoglutarate

FADH2 is generated during the citric acid cycle when:

c) succinate is converted to fumerate

Which enzyme of the citric acid cycle has a direct physical link with the electron transport chain in the inner membrane of the mitochondria?

succinate dehydrogenase

The pyruvate dehydrogenase complex can be regulated by all of the following EXCEPT:

e) covalent modification

ATP is synthesized from ADP at which step of the citric acid cycle?

b) succinyl CoA to succinate

The conversion of pyruvate to acetyl CoA takes place:

d) in the matrix of the mitochondria

The process of oxidative phosphorylation (electron transport chain) takes place:

c) on the inner mitochondrial membrane

Electrons that are flowing from Complex I to Complex III are transferred by:

b) ubiquinone (CoA)

The component of the electron transport chain that serves as the entry point for the electrons of NADH is:

a) Complex I

Each complex of the electron transport chain can move protons across the inner membrane EXCEPT for:

b) Complex II

Peter Mitchell originally proposed the chemiosmotic theory, which includes the proton motive force. This force is composed of:

d) the sum of the chemical gradient and the charge gradient

Which of the following statements regarding ATP transport into the mitochondria is CORRECT?

b) ADP enters the mitochondrial matrix only if ATP exits

Choose the correct path taken by a pair of electrons as it travels down the electron transport chain.

a) NADH --> Complex I --> CoQ --> Complex III --> cytochrome c --> Complex IV --> O2

ATP synthase can be down-regulated by all of the following except:

c) high levels of ADP

Non-shivering thermogenesis takes place when the protons of the proton motive force are moved to the _______ by uncoupling protein.

a)

The pentose phosphate pathway takes place in which compartment of the cell?

b) cytoplasm

Dehydration of glucose-6-phosphate at carbon 1 at the first step of the oxidative phase of the pentose phosphate pathway is catalyzed by:

b) glucose 6-phosphate dehydrogenase

The interconversion of three-, four-, five-, six-, and seven- carbon sugars occurs in which phase of the pentose phosphate pathway?

b) nonoxidative

Which mode of the pentose phosphate pathway would be most likely employed if the need for ribose 5-phosphate and NADPH are balanced?

b) Mode 2

Which mode of the pentose phosphate pathway would most likely be employed if rapid dividing cells needed more nucleotide synthesis?

a) Mode 1

Glucose 6-phosphate dehydrogenase reduces oxidized glutathione using the reducing power of:

c) NADPH

People who have a glucose 6-phosphate dehydrogenase deficiency will show all of the following conditions EXCEPT:

e) sensitivity to the malarial parasite plasmodium flaciparum

The pentose phosphate pathway generates ________ molecules of NADPH for each molecule of glucose 6-phosphate?

b) 2

Glucose cannot be stored in a free form in the cell because:

d) it disrupts the osmotic balance of the cell

How is glycogen phosphorylase b converted into glycogen phosphorylase a?

a) addition of a phosphate to a serine residue

Glucose 6-phosphate derived from glycogen cannot be:

e) transported or diffuse out of the cell

What enzyme can break only alpha-1,4-glycosidic bonds on glycogen branches?

c) phosphorylase

The allosteric activation of muscle phosphorylase is due to the binding of:

c) AMP

The activation of phosphorylase kinase directly requires:

c) calcium ions

What enzyme forms alpha-1,6-linkages during glycogen synthesis?

a) branching enzyme

Glucagon and epinephrine control both glycogen breakdown and glycogen synthesis through the enzyme:

b) protein kinase A

What enzyme is inactivated by protein phosphate 1 via dephosphorylation?

a) phosphorylase a

Which hormone during exercise would enhance the breakdown of glycogen to glucose for energy?

b) epinephrine