Question 1

Fatty acid synthesis is different in bacteria than in eukaryotic cells because .

Accepted Answer

A)  bacteria do not form malonyl CoA 
B)  eukaryotes use acetyl CoA to form malonyl CoA 
C)  bacteria do not form acetyl ACP 
D)  bacteria do not form acetoacetyl CoA 
A)  bacteria do not form malonyl CoA 
B)  eukaryotes use acetyl CoA to form malonyl CoA 
C)  bacteria do not form acetyl ACP 
D)  bacteria do not form acetoacetyl CoA

Question 2

Phosphatidylcholine synthesis occurs in the .

Accepted Answer

A)  endoplasmic reticulum of eukaryotic cells 
B)  Golgi apparatus 
C)  mitochondrion 
D)  plasma membrane 
A)  endoplasmic reticulum of eukaryotic cells 
B)  Golgi apparatus 
C)  mitochondrion 
D)  plasma membrane

Question 3

The main function of the bile salts is to .

Accepted Answer

A)  transport lipids to the intestinal wall 
B)  act as counterions for the ionized forms of lipids 
C)  cleave the ester bonds in triacylglycerols to release free fatty acids 
D)  form the surface layer of chylomicrons 
A)  transport lipids to the intestinal wall 
B)  act as counterions for the ionized forms of lipids 
C)  cleave the ester bonds in triacylglycerols to release free fatty acids 
D)  form the surface layer of chylomicrons

Question 4

CoA derivatives are the active thioesters in fatty acid oxidation.

Accepted Answer

A) True 
 B)False

Question 5

There are four steps in the β-oxidation pathway. Some reaction types are listed below. Give the proper reaction types in the order that they occur in the β-oxidation pathway. 1. condensation
2. oxidation
3. reduction
4. thiolysis
5. hydration
6. phosphorylation
7. rearrangement

Accepted Answer

A)  1,7,2,2 
B)  6,3,4,2 
C)  1,2,3,5 
D)  2,5,2,4 
A)  1,7,2,2 
B)  6,3,4,2 
C)  1,2,3,5 
D)  2,5,2,4

Question 6

What structure is shown below and what is its main function?

Accepted Answer

A)  coenzyme A; activation of fatty acids before β-oxidation 
B)  carnitine; transport of fatty acyl CoA into the mitochondrial matrix 
C)  taurocholate; one of the bile salts 
D)  acetoacetate; synthesis of fatty acids 
A)  coenzyme A; activation of fatty acids before β-oxidation 
B)  carnitine; transport of fatty acyl CoA into the mitochondrial matrix 
C)  taurocholate; one of the bile salts 
D)  acetoacetate; synthesis of fatty acids

Question 7

During starvation ketone bodies can take the place of glucose as a fuel for brain cells.

Accepted Answer

A) True 
 B)False

Question 8

Non-insulin-dependent diabetes mellitus NIDDM) is characterized by .

Accepted Answer

A)  insulin secretion that is always at levels well below normal 
B)  insufficient insulin levels initiated during gestational diabetes 
C)  a shortage of insulin receptors that leads to accumulation of blood glucose 
D)  an inherited genetic abnormality in the insulin gene that yields a much less active insulin 
A)  insulin secretion that is always at levels well below normal 
B)  insufficient insulin levels initiated during gestational diabetes 
C)  a shortage of insulin receptors that leads to accumulation of blood glucose 
D)  an inherited genetic abnormality in the insulin gene that yields a much less active insulin

Question 9

Properties of aspirin may include

Accepted Answer

A)  inhibition of COX activity. 
B)  increased production of prostaglandins. 
C)  Both A and B 
D)  None of the above 
A)  inhibition of COX activity. 
B)  increased production of prostaglandins. 
C)  Both A and B 
D)  None of the above

Question 10

The bile salts taurocholate and glycocholate are amphipathic derivatives of cholesterol.

Accepted Answer

A) True 
 B)False

Question 11

What is the major role of phospholipase A2?

Accepted Answer

A)  To cleave the phosphate group from phospholipids. 
B)  To phosphorylate the enzyme enoyl-CoA. 
C)  To hydrolyze an ester bond in glycerophospholipids to form lysophosphoglyceride. 
D)  To transport glycerophospholipids in the blood. 
A)  To cleave the phosphate group from phospholipids. 
B)  To phosphorylate the enzyme enoyl-CoA. 
C)  To hydrolyze an ester bond in glycerophospholipids to form lysophosphoglyceride. 
D)  To transport glycerophospholipids in the blood.

Question 12

In eukaryotes the enzyme complex called fatty acid synthase is responsible for the assembly of the fatty acid chain.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is a true statement, concerning HMG-CoA reductase?

Accepted Answer

A)  It is regulated by covalent modification of a serine in its active site. 
B)  It catalyzes the first committed step in cholesterol biosynthesis. 
C)  It causes the production of NADPH. 
D)  The product of the reaction it catalyzes is acetoacetyl CoA. 
A)  It is regulated by covalent modification of a serine in its active site. 
B)  It catalyzes the first committed step in cholesterol biosynthesis. 
C)  It causes the production of NADPH. 
D)  The product of the reaction it catalyzes is acetoacetyl CoA.

Question 14

Which of the following is not a stage of fatty acid synthesis?

Accepted Answer

A)  condensation of precursors 
B)  rearrangement 
C)  reduction 
D)  dehydration 
A)  condensation of precursors 
B)  rearrangement 
C)  reduction 
D)  dehydration

Question 15

Triacylglycerols are more efficient to store than carbohydrates because their hydrophobicity allows them to be stored in adipose cells without large amounts of bound water molecules.

Accepted Answer

A) True 
 B)False

Question 16

Which lipid form is transported across the inner mitochondrial membrane before β-oxidation?

Accepted Answer

A)  acylcarnitine 
B)  fatty acyl CoA 
C)  acetoacetyl CoA 
D)  lysophospholipid CoA 
A)  acylcarnitine 
B)  fatty acyl CoA 
C)  acetoacetyl CoA 
D)  lysophospholipid CoA

Question 17

Which do you expect to have the highest protein content by percent?

Accepted Answer

A)  VLDLs 
B)  ILDs 
C)  HDLs 
D)  All of the lipids above have about the same protein content. 
A)  VLDLs 
B)  ILDs 
C)  HDLs 
D)  All of the lipids above have about the same protein content.

Question 18

Snake venom can cause the lysis of red blood cells due to the presence of phospholipase A2.

Accepted Answer

A) True 
 B)False

Question 19

The reaction, Palmitoyl-ACP→Palmitate + HS-ACP proceeds via which of the following enzymes?

Accepted Answer

A)  thioesterase 
B)  ketoacyl-ACP synthase 
C)  transacylase 
D)  None of the above 
A)  thioesterase 
B)  ketoacyl-ACP synthase 
C)  transacylase 
D)  None of the above

Question 20

Which of the following is the regulated step of fatty acid synthesis in eukaryotes?

Accepted Answer

A)  carboxylation of acetyl CoA 
B)  transportation of mitochondrial acetyl CoA into the cytosol 
C)  assembly of the fatty acid chain 
D)  All of the above 
A)  carboxylation of acetyl CoA 
B)  transportation of mitochondrial acetyl CoA into the cytosol 
C)  assembly of the fatty acid chain 
D)  All of the above

Exam 16: Lipid Metabolism

Fatty acid synthesis is different in bacteria than in eukaryotic cells because .

Phosphatidylcholine synthesis occurs in the .

The main function of the bile salts is to .

CoA derivatives are the active thioesters in fatty acid oxidation.

There are four steps in the β-oxidation pathway. Some reaction types are listed below. Give the proper reaction types in the order that they occur in the β-oxidation pathway. 1. condensation 2. oxidation 3. reduction 4. thiolysis 5. hydration 6. phosphorylation 7. rearrangement

What structure is shown below and what is its main function?

During starvation ketone bodies can take the place of glucose as a fuel for brain cells.

Non-insulin-dependent diabetes mellitus NIDDM) is characterized by .

Properties of aspirin may include

The bile salts taurocholate and glycocholate are amphipathic derivatives of cholesterol.

What is the major role of phospholipase A2?

In eukaryotes the enzyme complex called fatty acid synthase is responsible for the assembly of the fatty acid chain.

Which of the following is a true statement, concerning HMG-CoA reductase?

Which of the following is not a stage of fatty acid synthesis?

Triacylglycerols are more efficient to store than carbohydrates because their hydrophobicity allows them to be stored in adipose cells without large amounts of bound water molecules.

Which lipid form is transported across the inner mitochondrial membrane before β-oxidation?

Which do you expect to have the highest protein content by percent?

Snake venom can cause the lysis of red blood cells due to the presence of phospholipase A2.

The reaction, Palmitoyl-ACP→Palmitate + HS-ACP proceeds via which of the following enzymes?

Which of the following is the regulated step of fatty acid synthesis in eukaryotes?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

What is the major role of phospholipase A₂?

Snake venom can cause the lysis of red blood cells due to the presence of phospholipase A₂.