Question 1

Which of the cellular organelles are enclosed by two cellular membranes?

Accepted Answer

A) Golgi 
B) lysosome 
C) nucleus 
D) endoplasmic reticulum 
A) Golgi 
B) lysosome 
C) nucleus 
D) endoplasmic reticulum C

Question 2

What experimental evidence supports the fluid mosaic model of biomembranes?

Accepted Answer

Results from fluorescence recovery after photobleaching (FRAP)experiments have demonstrated the two-dimensional movement of membrane components and allow quantitative measurement of the extent of membrane fluidity.

Question 3

The ________________________are transmembrane proteins.

Accepted Answer

A) lipid-anchored membrane proteins 
B) integral membrane proteins 
C) peripheral membrane proteins 
D) extracellular matrix proteins 
A) lipid-anchored membrane proteins 
B) integral membrane proteins 
C) peripheral membrane proteins 
D) extracellular matrix proteins B

Question 4

Peripheral membrane proteins

Accepted Answer

A) contain many hydrophobic amino acid residues. 
B) contain membrane spanning domains. 
C) have covalently attached lipid or fatty acid anchors. 
D) may noncovalently interact with phospholipid heads. 
A) contain many hydrophobic amino acid residues. 
B) contain membrane spanning domains. 
C) have covalently attached lipid or fatty acid anchors. 
D) may noncovalently interact with phospholipid heads.

Question 5

Describe how you would prepare liposomes from a biological membrane.

Accepted Answer

The first step would be to treat the bio

Question 6

An investigator wants to use FRAP to quantify the lateral movement of a specific plasma membrane protein,but to do so this investigator must first:

Accepted Answer

A) focus a laser on one region of the cell surface. 
B) measure the intensity of the fluorescence of the cell surface. 
C) label the cell with a fluorescent reagent that binds specifically to the cell surface. 
D) add detergents to make the cell surface more fluid. 
A) focus a laser on one region of the cell surface. 
B) measure the intensity of the fluorescence of the cell surface. 
C) label the cell with a fluorescent reagent that binds specifically to the cell surface. 
D) add detergents to make the cell surface more fluid.

Question 7

The enzyme in cholesterol biosynthesis subject to feedback inhibition is

Accepted Answer

A) ABCB4. 
B) desaturase. 
C) fatty acid synthase. 
D) HMG CoA reductase. 
A) ABCB4. 
B) desaturase. 
C) fatty acid synthase. 
D) HMG CoA reductase.

Question 8

Cholesterol,bile acids,ergosterol,and stigmasterol share all the following common structural features except

Accepted Answer

A) a four-ring structure. 
B) a hydroxyl group on first ring. 
C) a carboxylic acid group. 
D) a multiple carbon chain extending off the ring structure. 
A) a four-ring structure. 
B) a hydroxyl group on first ring. 
C) a carboxylic acid group. 
D) a multiple carbon chain extending off the ring structure.

Question 9

When using immunofluorescence microscopy with labeled Annexin V antibodies you found that there is a change in the distribution of the fluorescence when the cells were treated with tumor necrosis factor,an apoptosis-inducing agent.Your data show that this increase in Annexin V fluorescence increases specifically in the:

Accepted Answer

A) mitochondria. 
B) exoplasmic face of the plasma membrane. 
C) Golgi. 
D) endoplasmic reticulum. 
A) mitochondria. 
B) exoplasmic face of the plasma membrane. 
C) Golgi. 
D) endoplasmic reticulum.

Question 10

Describe how unesterified fatty acids unlinked to CoA are able to move through the aqueous environment of the cytoplasm.

Accepted Answer

Fatty acid-binding proteins contain a hy

Question 11

There are several enzymes involved in cholesterol biosynthetic pathway.Which of these is subject to feedback regulation? How does this enzyme sense cholesterol levels?

Accepted Answer

HMG-CoA reductase catalyzes the key rate

Question 12

Peripheral proteins bound to the exoplasmic face of the plasma membrane can also bind to:

Accepted Answer

A) cytoskeletal proteins. 
B) proteins of the ECM. 
C) the hydrophobic core of the phospholipid bilayer. 
D) proteins of the outer mitochondrial membrane. 
A) cytoskeletal proteins. 
B) proteins of the ECM. 
C) the hydrophobic core of the phospholipid bilayer. 
D) proteins of the outer mitochondrial membrane.

Question 13

Describe how charged amino acids guide the assembly of membrane complexes such as the T-cell receptor.

Accepted Answer

The T-cell receptor is composed of four

Question 14

The plasma membrane around a eukaryotic cell is composed of:

Accepted Answer

A) hydrophilic fatty acyl side chains. 
B) hydrophobic phospholipids. 
C) a phospholipid bilayer. 
D) none of the above 
A) hydrophilic fatty acyl side chains. 
B) hydrophobic phospholipids. 
C) a phospholipid bilayer. 
D) none of the above

Question 15

Proteins can be attached to the phospholipid bilayer plasma membrane by covalently linked hydrocarbon groups.Which of the following mechanisms are employed in this anchoring?

Accepted Answer

A) GPI 
B) prenylation 
C) acylation 
D) all of the above 
A) GPI 
B) prenylation 
C) acylation 
D) all of the above

Question 16

The major site of lipid synthesis in eukaryotic cells is the

Accepted Answer

A) nucleus. 
B) endoplasmic reticulum (ER). 
C) peroxisome. 
D) mitochondria. 
A) nucleus. 
B) endoplasmic reticulum (ER). 
C) peroxisome. 
D) mitochondria.

Question 17

Free and unesterified fatty acids bind to one of a number of chaperone proteins in order to be transported in the aqueous environment of the cytosol.Which of the following facilitates this intracellular transport?

Accepted Answer

A) fatty acid-binding proteins 
B) aquaporins 
C) flippases 
D) fatty acid synthase 
A) fatty acid-binding proteins 
B) aquaporins 
C) flippases 
D) fatty acid synthase

Question 18

Phosphate-containing lipids include all of the following except

Accepted Answer

A) plasmalogen. 
B) phospholipids. 
C) sphingolipid. 
D) triglyceride. 
A) plasmalogen. 
B) phospholipids. 
C) sphingolipid. 
D) triglyceride.

Question 19

Human alkaline phosphatase protein is attached to the plasma membrane by a GPI anchor.In an experiment you treat cells with each of the following enzymes and find one of them inhibits the activity of the protein because it releases it into the extracellular matrix.Which specific enzyme led you to conclude that this anchor on alkaline phosphatase was both necessary and sufficient for binding the protein to the membrane where it can perform its normal activity?

Accepted Answer

A) glycosyltransferases 
B) phospholipase C 
C) flippases 
D) none of the above 
A) glycosyltransferases 
B) phospholipase C 
C) flippases 
D) none of the above

Question 20

Cholesterol and phospholipids are transported between organelles by

Accepted Answer

A) Golgi-dependent mechanisms. 
B) incompletely characterized vesicle populations. 
C) direct contact between membranes and,to some extent,small,soluble lipid-transfer proteins. 
D) b and c 
A) Golgi-dependent mechanisms. 
B) incompletely characterized vesicle populations. 
C) direct contact between membranes and,to some extent,small,soluble lipid-transfer proteins. 
D) b and c

Exam 6: Bio-membrane Structure

Which of the cellular organelles are enclosed by two cellular membranes?

What experimental evidence supports the fluid mosaic model of biomembranes?

The ________________________are transmembrane proteins.

Peripheral membrane proteins

Describe how you would prepare liposomes from a biological membrane.

An investigator wants to use FRAP to quantify the lateral movement of a specific plasma membrane protein,but to do so this investigator must first:

The enzyme in cholesterol biosynthesis subject to feedback inhibition is

Cholesterol,bile acids,ergosterol,and stigmasterol share all the following common structural features except

Describe how unesterified fatty acids unlinked to CoA are able to move through the aqueous environment of the cytoplasm.

There are several enzymes involved in cholesterol biosynthetic pathway.Which of these is subject to feedback regulation? How does this enzyme sense cholesterol levels?

Peripheral proteins bound to the exoplasmic face of the plasma membrane can also bind to:

Describe how charged amino acids guide the assembly of membrane complexes such as the T-cell receptor.

The plasma membrane around a eukaryotic cell is composed of:

Proteins can be attached to the phospholipid bilayer plasma membrane by covalently linked hydrocarbon groups.Which of the following mechanisms are employed in this anchoring?

The major site of lipid synthesis in eukaryotic cells is the

Free and unesterified fatty acids bind to one of a number of chaperone proteins in order to be transported in the aqueous environment of the cytosol.Which of the following facilitates this intracellular transport?

Phosphate-containing lipids include all of the following except

Cholesterol and phospholipids are transported between organelles by

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

Nerve Cells

Immunology

Cancer

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