Question 1

Tay-Sachs disease is caused by a deficiency of __________ which results in an accumulation of ___________.

Accepted Answer

A) sphingomyelinase;sphingomyelin 
B) ceramidase;ceramide 
C) $\alpha$-galactosidase A;GM1 ganglioside 
D) lysosomal N-acetylhexosaminidase A;GM2 ganglioside 
E) $\beta$-glucosidase;glucosylceramide 
A) sphingomyelinase;sphingomyelin 
B) ceramidase;ceramide 
C) $\alpha$-galactosidase A;GM1 ganglioside 
D) lysosomal N-acetylhexosaminidase A;GM2 ganglioside 
E) $\beta$-glucosidase;glucosylceramide D

Question 2

Which of the following phospholipids is produced in eukaryotes but not prokaryotes?

Accepted Answer

A) phosphatidylglycerol 
B) phosphatidylserine 
C) phosphatidylethanolamine 
D) phosphatidylinositol 
E) none of the above 
A) phosphatidylglycerol 
B) phosphatidylserine 
C) phosphatidylethanolamine 
D) phosphatidylinositol 
E) none of the above D

Question 3

What is the term for the molecule shown below?

Accepted Answer

A) platelet-activating factor 
B) 1-alkyl-2-acetylglcerophosphoethanolamine 
C) serine plasmologen 
D) choline plasmologen 
E) ethanolamine plasmologen 
A) platelet-activating factor 
B) 1-alkyl-2-acetylglcerophosphoethanolamine 
C) serine plasmologen 
D) choline plasmologen 
E) ethanolamine plasmologen E

Question 4

In eukaryotes,the conversion of DHAP to 1-acylglycerol-3-phosphate is a two-step process.Show the reactants and products missing in the following scheme.

Accepted Answer

The answer of In eukaryotes,the conversion of DHAP to 1-acylglycerol-3-phosphate...

Question 5

The synthesis of 1 molecule of cholesterol requires _____ molecules of isopentenyl pyrophosphate,with each molecule of isopentenyl pyrophosphate requiring _____ molecules of acetyl-CoA.

Accepted Answer

A) 4;2 
B) 5;2 
C) 6;2 
D) 5;3 
E) 6;3 
A) 4;2 
B) 5;2 
C) 6;2 
D) 5;3 
E) 6;3

Question 6

Phospholipids are synthesized in the ___________,then transferred to the ____________ via transport vesicles.

Accepted Answer

A) smooth endoplasmic reticulum;Golgi complex 
B) rough endoplasmic reticulum;smooth endoplasmic reticulum 
C) smooth endoplasmic reticulum;lysosome 
D) Golgi complex;smooth endoplasmic reticulum 
E) Golgi complex;cell membrane 
A) smooth endoplasmic reticulum;Golgi complex 
B) rough endoplasmic reticulum;smooth endoplasmic reticulum 
C) smooth endoplasmic reticulum;lysosome 
D) Golgi complex;smooth endoplasmic reticulum 
E) Golgi complex;cell membrane

Question 7

Squalene epoxidase is an example of a mixed function oxidase,meaning that it uses both _______ and _______ as substrates.

Accepted Answer

A) ATP;NADPH 
B) ATP;O2 
C) NAD+;NADPH 
D) O2;NAD+ 
E) O2;NADPH 
A) ATP;NADPH 
B) ATP;O2 
C) NAD+;NADPH 
D) O2;NAD+ 
E) O2;NADPH

Question 8

Which of the following is used to activate phosphatidic acid for conversion to various phospholipids?

Accepted Answer

A) ATP 
B) UTP 
C) CTP 
D) GTP 
E) TTP 
A) ATP 
B) UTP 
C) CTP 
D) GTP 
E) TTP

Question 9

Which of the following is accomplished in one enzyme catalyzed reaction?

Accepted Answer

A) progesterone to androstenedione 
B) 17-hydroxyprogesterone to cortisol 
C) progesterone to aldosterone 
D) androstenedione to testosterone 
E) androstenedione to estradiol 
A) progesterone to androstenedione 
B) 17-hydroxyprogesterone to cortisol 
C) progesterone to aldosterone 
D) androstenedione to testosterone 
E) androstenedione to estradiol

Question 10

The synthesis of the glycosphingolipids begins with the reaction of either UDP-glucose or UDP-galactose with _____________.

Accepted Answer

A) ceramide 
B) sphinganine 
C) sphingosine 
D) sphingomyelin 
E) none of the above 
A) ceramide 
B) sphinganine 
C) sphingosine 
D) sphingomyelin 
E) none of the above

Question 11

In prokaryotes,_________ is used exclusively as the precursor for phosphatidic acid while in eukaryotes,_________is one of three possible precursors.

Accepted Answer

A) diacylglycerol;glycerol-3-phosphate 
B) glycerol-3-phosphate;dihydroxyacetone phosphate 
C) dihydroxyacetone phosphate;glycerol-3-phosphate 
D) 3-phosphoglycerate;diacylglycerol 
E) dihydroxyacetone phosphate;diacylglycerol 
A) diacylglycerol;glycerol-3-phosphate 
B) glycerol-3-phosphate;dihydroxyacetone phosphate 
C) dihydroxyacetone phosphate;glycerol-3-phosphate 
D) 3-phosphoglycerate;diacylglycerol 
E) dihydroxyacetone phosphate;diacylglycerol

Question 12

Show the reaction catalyzed by 3-hydroxy-3-methylglutrayl-CoA reductase.

Accepted Answer

The answer of Show the reaction catalyzed by 3-hydroxy-3-methylglutrayl-CoA reductase....

Question 13

Which of the following forms of vitamin A is covalently attached to a lysine residue of the protein opsin to form the complex called rhodopsin?

Accepted Answer

A) all-trans-retinal 
B) 11-cis-retinal 
C) all-trans-retinoic acid 
D) all-trans-retinol 
E) $\beta$-carotene 
A) all-trans-retinal 
B) 11-cis-retinal 
C) all-trans-retinoic acid 
D) all-trans-retinol 
E) $\beta$-carotene

Question 14

7-dehydrocholesterol reacts with _________ to produce cholecalciferol (vitamin D3)

Accepted Answer

A) UV light 
B) visible light 
C) NADPH 
D) NAD+ 
E) none of the above 
A) UV light 
B) visible light 
C) NADPH 
D) NAD+ 
E) none of the above

Question 15

What classification is given to the following molecule?

Accepted Answer

A) a prostaglandin G derivative 
B) a prostaglandin E derivative 
C) a leukotriene 
D) a thromboxane 
E) none of the above 
A) a prostaglandin G derivative 
B) a prostaglandin E derivative 
C) a leukotriene 
D) a thromboxane 
E) none of the above

Question 16

How is the activity of HMG-CoA reductase reduced?

Accepted Answer

A) allosteric inhibition by cholesterol 
B) ubiquitination in response to sterol accumulation resulting in proteolysis 
C) serine phosphorylation by an insulin-activated protein kinase 
D) tyrosine phosphorylation by AMPK 
E) none of the above 
A) allosteric inhibition by cholesterol 
B) ubiquitination in response to sterol accumulation resulting in proteolysis 
C) serine phosphorylation by an insulin-activated protein kinase 
D) tyrosine phosphorylation by AMPK 
E) none of the above

Question 17

Which of the following explains why the bile acids are much better suited than cholesterol for use as emulsification agents for fats?

Accepted Answer

A) cholesterol is oxidized to form the more polar molecule 7-hydroxycholesterol in route to formation of the bile acids 
B) while cholesterol contains a hydroxyl group as its sole hydrophilic functionality,cholic acid contains 3 hydroxyl groups and a carboxylic acid 
C) cholate is conjugated with glycine to make glycocholate 
D) cholate is conjugated with taurine to make taurocholate 
E) all of the above 
A) cholesterol is oxidized to form the more polar molecule 7-hydroxycholesterol in route to formation of the bile acids 
B) while cholesterol contains a hydroxyl group as its sole hydrophilic functionality,cholic acid contains 3 hydroxyl groups and a carboxylic acid 
C) cholate is conjugated with glycine to make glycocholate 
D) cholate is conjugated with taurine to make taurocholate 
E) all of the above

Question 18

Which of the following is the regulatory step in cholesterol synthesis?

Accepted Answer

A) HMG-CoA synthase 
B) HMG-CoA lyase 
C) HMG-CoA reductase 
D) squalene synthase 
E) squalene epoxidase 
A) HMG-CoA synthase 
B) HMG-CoA lyase 
C) HMG-CoA reductase 
D) squalene synthase 
E) squalene epoxidase

Question 19

Which of the following correctly identifies the order of carbocations found in the mechanism of squalene synthase?

Accepted Answer

A) tertiary carbocation;allylic carbocation;tertiary cyclopropylcarbinyl carbocation 
B) tertiary carbocation;tertiary cyclopropylcarbinyl carbocation;allylic carbocation 
C) allylic carbocation;tertiary cyclopropylcarbinyl carbocation;tertiary carbocation 
D) allylic carbocation;tertiary carbocation;tertiary cyclopropylcarbinyl carbocation 
E) tertiary cyclopropylcarbinyl carbocation ;allylic carbocation;tertiary carbocation 
A) tertiary carbocation;allylic carbocation;tertiary cyclopropylcarbinyl carbocation 
B) tertiary carbocation;tertiary cyclopropylcarbinyl carbocation;allylic carbocation 
C) allylic carbocation;tertiary cyclopropylcarbinyl carbocation;tertiary carbocation 
D) allylic carbocation;tertiary carbocation;tertiary cyclopropylcarbinyl carbocation 
E) tertiary cyclopropylcarbinyl carbocation ;allylic carbocation;tertiary carbocation

Question 20

Show the products of the following reaction and name them:

Accepted Answer

The answer of Show the products of the following reaction...

Exam 19: Lipid Metabolism Ii: Membrane Lipids, steroids, isoprenoids, and Eicosanoids

Tay-Sachs disease is caused by a deficiency of __________ which results in an accumulation of ___________.

Which of the following phospholipids is produced in eukaryotes but not prokaryotes?

What is the term for the molecule shown below?

In eukaryotes,the conversion of DHAP to 1-acylglycerol-3-phosphate is a two-step process.Show the reactants and products missing in the following scheme.

The synthesis of 1 molecule of cholesterol requires _____ molecules of isopentenyl pyrophosphate,with each molecule of isopentenyl pyrophosphate requiring _____ molecules of acetyl-CoA.

Phospholipids are synthesized in the ___________,then transferred to the ____________ via transport vesicles.

Squalene epoxidase is an example of a mixed function oxidase,meaning that it uses both _______ and _______ as substrates.

Which of the following is used to activate phosphatidic acid for conversion to various phospholipids?

Which of the following is accomplished in one enzyme catalyzed reaction?

The synthesis of the glycosphingolipids begins with the reaction of either UDP-glucose or UDP-galactose with _____________.

In prokaryotes,_________ is used exclusively as the precursor for phosphatidic acid while in eukaryotes,_________is one of three possible precursors.

Show the reaction catalyzed by 3-hydroxy-3-methylglutrayl-CoA reductase.

Which of the following forms of vitamin A is covalently attached to a lysine residue of the protein opsin to form the complex called rhodopsin?

7-dehydrocholesterol reacts with _________ to produce cholecalciferol (vitamin D3)

What classification is given to the following molecule?

How is the activity of HMG-CoA reductase reduced?

Which of the following explains why the bile acids are much better suited than cholesterol for use as emulsification agents for fats?

Which of the following is the regulatory step in cholesterol synthesis?

Which of the following correctly identifies the order of carbocations found in the mechanism of squalene synthase?

Show the products of the following reaction and name them:

The Scope of Biochemistry

The Matrix of Life: Weak Interactions in an Aqueous Environment

The Energetics of Life

Nucleic Acids

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Contractile Proteins and Molecular Motors

Carbohydrates: Sugars,saccharides,glycans

Lipids,membranes and Cellular Transport

Enzymes: Biological Catalysts

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

Citric Acid Cycle and Glyoxylate Cycle

Electron Transport, oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism I: Fatty Acids,triacylglycerols,and Lipoproteins

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Metabolism of Nitrogenous Compounds I: Principles of Biosynthesis, utilization, and Turnover

Metabolism of Nitogenous Compounds Ii: Amino Acids, porphyrins, and Neurotransmitters

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes,genomes and Chromosomes

Dna Replication

Dna Restructuring: Repair,recombination,rearrangement,amplification

Information Readout: Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

Tay-Sachs disease is caused by a deficiency of which results in an accumulation of _.

The synthesis of 1 molecule of cholesterol requires _ molecules of isopentenyl pyrophosphate,with each molecule of isopentenyl pyrophosphate requiring _ molecules of acetyl-CoA.

Phospholipids are synthesized in the _,then transferred to the __ via transport vesicles.

Squalene epoxidase is an example of a mixed function oxidase,meaning that it uses both _ and _ as substrates.

In prokaryotes,_ is used exclusively as the precursor for phosphatidic acid while in eukaryotes,_is one of three possible precursors.

7-dehydrocholesterol reacts with _________ to produce cholecalciferol (vitamin D₃)