Question 1

The smallest precursor molecule cholesterol is derived from

Accepted Answer

A)  squalene. 
B)  isoprene. 
C)  arachidonic acid. 
D)  acetyl-CoA. 
A)  squalene. 
B)  isoprene. 
C)  arachidonic acid. 
D)  acetyl-CoA.

Question 2

What extra enzyme types are often required in the degradation of polyunsaturated fats by the   -oxidation pathway?

Accepted Answer

A)  reductase and isomerase 
B)  hydrolase and isomerase 
C)  oxidoreductase and reductase 
D)  synthase and isomerase 
A)  reductase and isomerase 
B)  hydrolase and isomerase 
C)  oxidoreductase and reductase 
D)  synthase and isomerase

Question 3

Which of the following causes inhibition of fatty acid synthesis?

Accepted Answer

A)  increased insulin 
B)  increased AMP-activated protein kinase (AMPK) 
C)  decreased cytoplasmic acyl-CoA 
D)  increased cytoplasmic acetyl-CoA 
A)  increased insulin 
B)  increased AMP-activated protein kinase (AMPK) 
C)  decreased cytoplasmic acyl-CoA 
D)  increased cytoplasmic acetyl-CoA

Question 4

What are the known components of atherosclerotic plaques?

Accepted Answer

Cholesterol,various

Question 5

The   -oxidation of mono- and polyunsaturated fatty acids

Accepted Answer

A)  requires an extra cycle through the pathway. 
B)  involves the reduction of the double bonds and then the continuation of  -oxidation. 
C)  yields succinyl-CoA. 
D)  involves isomerization and in some cases reduction of the double bonds before the continuation of  -oxidation. 
A)  requires an extra cycle through the pathway. 
B)  involves the reduction of the double bonds and then the continuation of  -oxidation. 
C)  yields succinyl-CoA. 
D)  involves isomerization and in some cases reduction of the double bonds before the continuation of  -oxidation.

Question 6

Which enzyme catalyzes the modification of a fatty acid,so that it can be transported into the mitochondria for oxidation?

Accepted Answer

A)  acyl-CoA dehydrogenase 
B)  acetyl-CoA carboxylase 
C)  fatty acyl-CoA synthetase 
D)  carnitine acyltransferase I 
A)  acyl-CoA dehydrogenase 
B)  acetyl-CoA carboxylase 
C)  fatty acyl-CoA synthetase 
D)  carnitine acyltransferase I

Question 7

List the four key steps in the synthesis of cholesterol.

Accepted Answer

(1)Three acetyl-coA molecules are combin

Question 8

Draw and name the two products obtained from the last round of   
-oxidation of an odd-chain fatty acid.

Accepted Answer

Acetyl-CoA

Question 9

Why is less ATP obtained from the average carbon in a sugar molecule than from a carbon in a fat molecule?

Accepted Answer

A)  The sugar carbons require more water weight during cellular storage. 
B)  The carbons in fatty acids are a more reduced form of carbon than those in sugars. 
C)  The sugar carbons yield more NADH than ATP. 
D)  The sugar carbons are derived from CO2. 
A)  The sugar carbons require more water weight during cellular storage. 
B)  The carbons in fatty acids are a more reduced form of carbon than those in sugars. 
C)  The sugar carbons yield more NADH than ATP. 
D)  The sugar carbons are derived from CO2.

Question 10

The regulation of Acetyl-CoA carboxylase is

Accepted Answer

A)  activated by glucagon. 
B)  activated by acyl-CoA binding. 
C)  stimulated by citrate. 
D)  inactivated by insulin. 
A)  activated by glucagon. 
B)  activated by acyl-CoA binding. 
C)  stimulated by citrate. 
D)  inactivated by insulin.

Question 11

In order for a fatty acyl-CoA to be moved into the mitochondria for   -oxidation,it must be

Accepted Answer

A)  transported by the carnitine-acylcarnitine translocase. 
B)  activated by ATP. 
C)  reduced by NADH and FADH2. 
D)  hydrolyzed into acetyl-coA fragments. 
A)  transported by the carnitine-acylcarnitine translocase. 
B)  activated by ATP. 
C)  reduced by NADH and FADH2. 
D)  hydrolyzed into acetyl-coA fragments.

Question 12

What precursors are required for the breakdown of palmitate?

Accepted Answer

A)  14 ATP and 14 NADH 
B)  ATP and CoA 
C)  acetyl-CoA 
D)  NADH and FADH2 
A)  14 ATP and 14 NADH 
B)  ATP and CoA 
C)  acetyl-CoA 
D)  NADH and FADH2

Question 13

How are double bonds added to fatty acid chains in humans?

Accepted Answer

A)  The smooth endoplasmic reticulum is involved in elongating and unsaturating fatty acids. 
B)  FAD is used as an oxidant to create the double bonds in the smooth endoplasmic reticulum. 
C)  Unsaturated fatty acids are not made by humans and are therefore essential fats. 
D)  Fatty acid desaturase enzymes use O2 and NADH to add double bonds to fatty acids. 
A)  The smooth endoplasmic reticulum is involved in elongating and unsaturating fatty acids. 
B)  FAD is used as an oxidant to create the double bonds in the smooth endoplasmic reticulum. 
C)  Unsaturated fatty acids are not made by humans and are therefore essential fats. 
D)  Fatty acid desaturase enzymes use O2 and NADH to add double bonds to fatty acids.

Question 14

The final formation of cholesterol from squalene involves

Accepted Answer

A)  condensation with HMG-CoA and mevalonate. 
B)  more than 19 reactions including cyclization and oxidation. 
C)  oxidation and the addition of acyl-CoA. 
D)  dimerization and oxidation of squalene. 
A)  condensation with HMG-CoA and mevalonate. 
B)  more than 19 reactions including cyclization and oxidation. 
C)  oxidation and the addition of acyl-CoA. 
D)  dimerization and oxidation of squalene.

Question 15

Which is true of the acyl carrier protein (ACP)?

Accepted Answer

A)  It transports the fatty acid chain during oxidation and synthesis. 
B)  It directs the growing fatty acid chain from one enzyme active site to another in the fatty acid synthesis pathway. 
C)  It requires ATP for proper function. 
D)  It catalyzes the delivery of fatty acyl chains from the mitochondria to the cytosol. 
A)  It transports the fatty acid chain during oxidation and synthesis. 
B)  It directs the growing fatty acid chain from one enzyme active site to another in the fatty acid synthesis pathway. 
C)  It requires ATP for proper function. 
D)  It catalyzes the delivery of fatty acyl chains from the mitochondria to the cytosol.

Question 16

How many ATPs are obtained from the complete   -oxidation of one mole of stearoyl-CoA (18Cs)compared with three molecules of glucose (3   6C = 18Cs)?

Accepted Answer

A)  106 versus 32 
B)  100 versus 100 
C)  36 versus 90 
D)  120 versus 90 
A)  106 versus 32 
B)  100 versus 100 
C)  36 versus 90 
D)  120 versus 90

Question 17

List the primary three physiological roles played by cholesterol or cholesterol derivatives.

Accepted Answer

Cholesterol is converted to bile acids f

Question 18

For every two carbons that are added to a growing fatty acid chain in the fatty acid synthesis pathway,__________ ATPs and __________ NADPHs are required.

Accepted Answer

A)  0; 1 
B)  1; 2 
C)  2; 1 
D)  0; 2 
A)  0; 1 
B)  1; 2 
C)  2; 1 
D)  0; 2

Question 19

Which group is responsible for activating phosphatidic acid for the synthesis of phospholipids?

Accepted Answer

A)  CoA 
B)  ATP 
C)  CO2 
D)  CTP 
A)  CoA 
B)  ATP 
C)  CO2 
D)  CTP

Question 20

Name the enzyme in the following reaction:

Accepted Answer

Phosphatid

Exam 16: Lipid Metabolism

The smallest precursor molecule cholesterol is derived from

What extra enzyme types are often required in the degradation of polyunsaturated fats by the -oxidation pathway?

Which of the following causes inhibition of fatty acid synthesis?

What are the known components of atherosclerotic plaques?

The -oxidation of mono- and polyunsaturated fatty acids

Which enzyme catalyzes the modification of a fatty acid,so that it can be transported into the mitochondria for oxidation?

List the four key steps in the synthesis of cholesterol.

Draw and name the two products obtained from the last round of -oxidation of an odd-chain fatty acid.

Why is less ATP obtained from the average carbon in a sugar molecule than from a carbon in a fat molecule?

The regulation of Acetyl-CoA carboxylase is

In order for a fatty acyl-CoA to be moved into the mitochondria for -oxidation,it must be

What precursors are required for the breakdown of palmitate?

How are double bonds added to fatty acid chains in humans?

The final formation of cholesterol from squalene involves

Which is true of the acyl carrier protein (ACP)?

How many ATPs are obtained from the complete -oxidation of one mole of stearoyl-CoA (18Cs)compared with three molecules of glucose (3 6C = 18Cs)?

List the primary three physiological roles played by cholesterol or cholesterol derivatives.

For every two carbons that are added to a growing fatty acid chain in the fatty acid synthesis pathway,__________ ATPs and __________ NADPHs are required.

Which group is responsible for activating phosphatidic acid for the synthesis of phospholipids?

Name the enzyme in the following reaction:

Principles of Biochemistry

Physical Biochemistry: Energy Conversion,water,and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

Dna Replication, repair, and Recombination

Rna Synthesis, processing, and Gene Silencing

Protein Synthesis, posttranslational Modification, and Transport

Gene Regulation

Filters

For every two carbons that are added to a growing fatty acid chain in the fatty acid synthesis pathway, ATPs and NADPHs are required.