Question 1

Acyl carrier protein has the same ____ group as the "business end" of ____.

Accepted Answer

A)   thiamin; TPP
B)   biotin; acetyl-CoA carboxylase
C)   phosphoadenosine; cAMP
D)   pyridoxal phosphate; vitamin B6
E)   phosphopantetheine; CoA E

Question 2

Which of the following catalyzes the conversion of cholesterol to pregnenolone, the first step in the conversion of cholesterol to steroid based hormones?

Accepted Answer

A)   7-α-hydroxylase
B)   desmolase
C)   steroid 5-α-reductase
D)   aromatase
E)   17-ketoreductase A

Question 3

____ are all derived from 20-carbon fatty acids that are acylated to membrane phospholipids and released by the enzyme ____.

Accepted Answer

A)   Arachidonates; triacylglycerol lipase
B)   Arachidonates; phospholipase A1
C)   Eicosanoids; phospholipase A1
D)   Eicosanoids; phospholipase A2
E)   Arachidonates; phospholipase A2 D

Question 4

The reaction catalyzed by ____ is: Citrate + ATP +CoA → acetyl-CoA + ____ + ____.

Accepted Answer

A)   citrate synthase; malate; AMP + Pi
B)   citrate synthase; OAA; AMP + PPi
C)   ATP-citrate lyase; OAA; AMP + PPi
D)   ATP-citrate lyase; OAA; ADP + Pi
E)   citrate synthase; OAA; ADP + Pi

Question 5

The appropriate sequence of intermediates between mevalonate and squalene are:
A.geranyl pyrophosphate
B.isopentenyl pyrophosphate
C.5-phosphomevalonate
D.farnesyl pyrophosphate
E.dimethylallyl pyrophosphate

Accepted Answer

A)   A, C, D, B, E
B)   C, B, E, A, D
C)   C, E, A, D, B
D)   E, C, B, D, A
E)   B, C, D, A, E

Question 6

Phosphorylation of regulatory sites on acetyl-CoA carboxylase ____ the affinity for citrate and ____ the affinity for fatty acyl-CoAs requiring ____ levels of fatty acyl-CoAs for inhibition.

Accepted Answer

A)   increases; decreases; low
B)   decreases; increases; high
C)   decreases; increases; low
D)   increases; decreases; high
E)   none are correct

Question 7

The formation of acetoacetyl-ACP is catalyzed by:

Accepted Answer

A)   β-ketoacyl-ACP synthase (KSase) .
B)   acetyl-CoA carboxylase.
C)   acetyl transacylase.
D)   β-hydroxyacyl dehydratase.
E)   β-ketoacyl reductase.

Question 8

In E. coli, β-hydroxydecanoyl-ACP is dehydrated by β-hydroxydecanoyl thioester dehydrase to form a double bond ____ to the thioester in the ____ configuration which is further elongated to form ____.

Accepted Answer

A)   α,β; cis; palmitoyl-ACP
B)   β,γ; cis; palmitoleoyl-ACP
C)   β,γ; trans; palmitoleoyl-ACP
D)   α,β; trans; palmitoleoyl-ACP
E)   β,γ; cis; palmitoyl-ACP

Question 9

The coenzyme(s) of acetyl-CoA carboxylase is/are:

Accepted Answer

A)   biotin and NAD+.
B)   TPP.
C)   NADH and FAD.
D)   TPP and folic acid.
E)   biotin.

Question 10

Platelet-activating factor displays dramatic ability to ____ blood vessels and thus ____ blood pressure, and to aggregate platelets.

Accepted Answer

A)   dilate; reduce.
B)   dilate; reduce
C)   constrict; increase./
D)   constrict; increase.
E)   constrict; increase

Question 11

Lipoproteins consist of a core of ____ and ____ surrounded by a single layer of ____, into which is inserted ____ and ____.

Accepted Answer

A)   proteins; triacylglycerols; cholesterol esters; phospholipids; cholesterol
B)   triacylglycerols; cholesterol esters; phospholipids; proteins; cholesterol
C)   phospholipids; cholesterol esters; triacylglycerols; proteins; cholesterol
D)   cholesterol esters; proteins; cholesterol; phospholipids; triacylglycerols
E)   triacylglycerols; cholesterol; proteins; cholesterol esters; phospholipids

Question 12

Stearoyl-CoA desaturase has all of the following characteristics EXCEPT:

Accepted Answer

A)   NADH and O2 are required.
B)   produces a trans double bond.
C)   involves cytochrome b5 reductase.
D)   involves cytochrome b5.
E)   occurs in the endoplasmic reticulum.

Question 13

All are regulatory mechanisms of HMG-CoA reductase EXCEPT:

Accepted Answer

A)   low [cholesterol] increases mRNA for HMG-CoA reductase.
B)   high [cholesterol] increases half-life for HMG-CoA reductase.
C)   high [cholesterol] results in lower mRNA for HMG-CoA reductase.
D)   phosphorylation by cAMP cascade inactivates HMG-CoA reductase.
E)   phosphatases activate HMG-CoA reductase.

Question 14

Sphinganine is acylated in the ____-position.

Accepted Answer

A)   3-OH
B)   2-NH2
C)   1-OH
D)   3-NH2
E)   all are true

Question 15

Discuss the functions of glucocorticoids.​

Accepted Answer

The answer of Discuss the functions of glucocorticoids.​...

Question 16

Male baldness, prostate hyperplasia and prostate cancer have been implicated in elevated levels of ____ and treatment involves inhibition of ____.

Accepted Answer

A)   glucocorticoids; gluconeogenesis
B)   stanozolol; lactate dehydrogenase
C)   dihydrotestosterone; steroid 5α-reductase
D)   cholesterol; mevinolin
E)   none of the above

Question 17

In fatty acid synthase, the correct sequence of enzyme catalyzed reactions are:
A.β-ketoacyl-ACP synthase
B.β-ketoacyl reductase
C.β-hydroxyacyl dehydratase
D.enoyl reductase
E.acetyl transferase

Accepted Answer

A)   A, B, C, D, E
B)   C, B, D, E, A
C)   B, A, C, D, E
D)   A, C, B, E, D
E)   D, E, A, B, C

Question 18

Dietary lipids are "packaged" in the intestine into ____ for transport via the lymphatic system.

Accepted Answer

A)   chylomicrons
B)   HDL
C)   IDL
D)   VLDL
E)   LDL

Question 19

There is no transporter for acetyl-CoA to exit the mitochondria, so the carbons must be converted to ____ for transport to the cytosol.

Accepted Answer

A)   acetone
B)   butyrate
C)   citrate
D)   pyruvate
E)   malonate

Question 20

Which of the following statements regarding phosphorylation of acetyl-CoA carboxylase is correct?

Accepted Answer

A)   phosphorylation causes activation only in the presence of palmitoyl-CoA
B)   phosphorylation is a result of glucagon binding to its receptor
C)   high [citrate] inhibits the phosphorylated form
D)   phosphorylation causes separation of the polymeric form of the enzyme to inactive protomers
E)   both b and d are true

Exam 24: Lipid Biosynthesis

Acyl carrier protein has the same group as the "business end" of .

Which of the following catalyzes the conversion of cholesterol to pregnenolone, the first step in the conversion of cholesterol to steroid based hormones?

are all derived from 20-carbon fatty acids that are acylated to membrane phospholipids and released by the enzyme .

The reaction catalyzed by is: Citrate + ATP +CoA → acetyl-CoA + + .

The appropriate sequence of intermediates between mevalonate and squalene are: A.geranyl pyrophosphate B.isopentenyl pyrophosphate C.5-phosphomevalonate D.farnesyl pyrophosphate E.dimethylallyl pyrophosphate

Phosphorylation of regulatory sites on acetyl-CoA carboxylase the affinity for citrate and the affinity for fatty acyl-CoAs requiring levels of fatty acyl-CoAs for inhibition.

The formation of acetoacetyl-ACP is catalyzed by:

In E. coli, β-hydroxydecanoyl-ACP is dehydrated by β-hydroxydecanoyl thioester dehydrase to form a double bond to the thioester in the configuration which is further elongated to form .

The coenzyme(s) of acetyl-CoA carboxylase is/are:

Platelet-activating factor displays dramatic ability to blood vessels and thus blood pressure, and to aggregate platelets.

Lipoproteins consist of a core of and surrounded by a single layer of , into which is inserted and .

Stearoyl-CoA desaturase has all of the following characteristics EXCEPT:

All are regulatory mechanisms of HMG-CoA reductase EXCEPT:

Sphinganine is acylated in the ____-position.

Discuss the functions of glucocorticoids.

Male baldness, prostate hyperplasia and prostate cancer have been implicated in elevated levels of and treatment involves inhibition of .

In fatty acid synthase, the correct sequence of enzyme catalyzed reactions are: A.β-ketoacyl-ACP synthase B.β-ketoacyl reductase C.β-hydroxyacyl dehydratase D.enoyl reductase E.acetyl transferase

Dietary lipids are "packaged" in the intestine into ____ for transport via the lymphatic system.

There is no transporter for acetyl-CoA to exit the mitochondria, so the carbons must be converted to ____ for transport to the cytosol.

Which of the following statements regarding phosphorylation of acetyl-CoA carboxylase is correct?

Exam 24: Lipid Biosynthesis

Acyl carrier protein has the same ____ group as the "business end" of ____.

Which of the following catalyzes the conversion of cholesterol to pregnenolone, the first step in the conversion of cholesterol to steroid based hormones?

____ are all derived from 20-carbon fatty acids that are acylated to membrane phospholipids and released by the enzyme ____.

The reaction catalyzed by ____ is: Citrate + ATP +CoA → acetyl-CoA + ____ + ____.

The appropriate sequence of intermediates between mevalonate and squalene are: A.geranyl pyrophosphate B.isopentenyl pyrophosphate C.5-phosphomevalonate D.farnesyl pyrophosphate E.dimethylallyl pyrophosphate

Phosphorylation of regulatory sites on acetyl-CoA carboxylase ____ the affinity for citrate and ____ the affinity for fatty acyl-CoAs requiring ____ levels of fatty acyl-CoAs for inhibition.

The formation of acetoacetyl-ACP is catalyzed by:

In E. coli, β-hydroxydecanoyl-ACP is dehydrated by β-hydroxydecanoyl thioester dehydrase to form a double bond ____ to the thioester in the ____ configuration which is further elongated to form ____.

The coenzyme(s) of acetyl-CoA carboxylase is/are:

Platelet-activating factor displays dramatic ability to ____ blood vessels and thus ____ blood pressure, and to aggregate platelets.

Lipoproteins consist of a core of ____ and ____ surrounded by a single layer of ____, into which is inserted ____ and ____.

Stearoyl-CoA desaturase has all of the following characteristics EXCEPT:

All are regulatory mechanisms of HMG-CoA reductase EXCEPT:

Sphinganine is acylated in the ____-position.

Discuss the functions of glucocorticoids.​

Male baldness, prostate hyperplasia and prostate cancer have been implicated in elevated levels of ____ and treatment involves inhibition of ____.

In fatty acid synthase, the correct sequence of enzyme catalyzed reactions are: A.β-ketoacyl-ACP synthase B.β-ketoacyl reductase C.β-hydroxyacyl dehydratase D.enoyl reductase E.acetyl transferase

Dietary lipids are "packaged" in the intestine into ____ for transport via the lymphatic system.

There is no transporter for acetyl-CoA to exit the mitochondria, so the carbons must be converted to ____ for transport to the cytosol.

Which of the following statements regarding phosphorylation of acetyl-CoA carboxylase is correct?

Acyl carrier protein has the same group as the "business end" of .

are all derived from 20-carbon fatty acids that are acylated to membrane phospholipids and released by the enzyme .

The reaction catalyzed by is: Citrate + ATP +CoA → acetyl-CoA + + .

Phosphorylation of regulatory sites on acetyl-CoA carboxylase the affinity for citrate and the affinity for fatty acyl-CoAs requiring levels of fatty acyl-CoAs for inhibition.

In E. coli, β-hydroxydecanoyl-ACP is dehydrated by β-hydroxydecanoyl thioester dehydrase to form a double bond to the thioester in the configuration which is further elongated to form .

Platelet-activating factor displays dramatic ability to blood vessels and thus blood pressure, and to aggregate platelets.

Lipoproteins consist of a core of and surrounded by a single layer of , into which is inserted and .

Discuss the functions of glucocorticoids.

Male baldness, prostate hyperplasia and prostate cancer have been implicated in elevated levels of and treatment involves inhibition of .