Question 1

Which of the following is true about protein folding?

Accepted Answer

A) Amino acids cluster in the primary sequence so that all the hydrophobic amino acids are near each other to facilitate folding into the hydrophobic core of the tertiary structure. 
B) All known proteins have well-ordered conformations. 
C) Amino acids with hydrophobic,nonpolar side chains stabilize the tertiary structure through hydrogen bonding with water molecules surrounding the proteins. 
D) Elements from the secondary structure are maintained in the tertiary structure. 
A) Amino acids cluster in the primary sequence so that all the hydrophobic amino acids are near each other to facilitate folding into the hydrophobic core of the tertiary structure. 
B) All known proteins have well-ordered conformations. 
C) Amino acids with hydrophobic,nonpolar side chains stabilize the tertiary structure through hydrogen bonding with water molecules surrounding the proteins. 
D) Elements from the secondary structure are maintained in the tertiary structure.

Question 2

Which of the following modifications marks a protein for degradation in proteasomes?

Accepted Answer

A) phosphorylation 
B) ubiquitinylation 
C) acetylation 
D) glycosylation 
A) phosphorylation 
B) ubiquitinylation 
C) acetylation 
D) glycosylation

Question 3

Western blotting is a method for detecting:

Accepted Answer

A) DNA. 
B) RNA. 
C) protein. 
D) carbohydrate. 
A) DNA. 
B) RNA. 
C) protein. 
D) carbohydrate.

Question 4

Which of the following is true about enzymes?

Accepted Answer

A) The catalytic site is responsible for substrate specificity. 
B) Reactions catalyzed by enzymes give the products more free energy than reactions that occur spontaneously. 
C) The rate of an enzymatic reaction is always proportional to the concentration of the substrate . 
D) Enzymes increase reaction rates by lowering the activation energy needed to reach the transition state. 
A) The catalytic site is responsible for substrate specificity. 
B) Reactions catalyzed by enzymes give the products more free energy than reactions that occur spontaneously. 
C) The rate of an enzymatic reaction is always proportional to the concentration of the substrate . 
D) Enzymes increase reaction rates by lowering the activation energy needed to reach the transition state.

Question 5

What is the basis for separation of proteins by two-dimensional gel electrophoresis? Why is this better for resolving a mixture of proteins?

Accepted Answer

In the first dimension,proteins are sepa

Question 6

You are studying an oligopeptide composed of eight amino acids.The four amino acids nearest the C terminus are nonpolar.The two amino acids nearest the N terminus are charged.The middle two amino acids are polar.Which amino acid is likely to be labeled as number 2?

Accepted Answer

A) threonine 
B) phenylalanine 
C) glutamine 
D) lysine 
A) threonine 
B) phenylalanine 
C) glutamine 
D) lysine

Question 7

Which of the following does NOT impose limits on protein folding?

Accepted Answer

A) ability of side chains to form hydrogen and ionic bonds 
B) backbone sequence of the polypeptide 
C) rotations of the planes around the peptide bonds 
D) size of side chains 
A) ability of side chains to form hydrogen and ionic bonds 
B) backbone sequence of the polypeptide 
C) rotations of the planes around the peptide bonds 
D) size of side chains

Question 8

There are many important roles for the dynamic nature of proteins in a cell.Which of the following is NOT likely to describe one such reason?

Accepted Answer

A) A protein's structure determines its function. 
B) Other molecules could be needed to allow proteins to fold into their active (ordered)conformation. 
C) Quaternary structures are usually very transient (occur for short periods of time). 
D) Proteins are crucial for many cell functions. 
A) A protein's structure determines its function. 
B) Other molecules could be needed to allow proteins to fold into their active (ordered)conformation. 
C) Quaternary structures are usually very transient (occur for short periods of time). 
D) Proteins are crucial for many cell functions.

Question 9

The correct order for molecular chaperone-mediated protein folding is:
I - exchange of ATP for ADP on chaperone
II - chaperone undergoes conformational change,which affects protein folding
III - chaperone binds to exposed hydrophobic residues on unfolded protein
IV - folded protein is released

Accepted Answer

A) I,II,III,IV 
B) III,II,I,IV 
C) III,I,II,IV 
D) II,III,I,IV 
A) I,II,III,IV 
B) III,II,I,IV 
C) III,I,II,IV 
D) II,III,I,IV

Question 10

Changes in the conformational shape of an enzyme that diminish the size of its ligand-binding pocket are likely to affect an enzyme's:

Accepted Answer

A) specificity. 
B) affinity. 
C) epitope. 
D) specificity and affinity. 
A) specificity. 
B) affinity. 
C) epitope. 
D) specificity and affinity.

Question 11

All the following statements about enzymes are true except:

Accepted Answer

A) they function in an aqueous environment. 
B) they lower the activation energy of a reaction. 
C) they increase the rate of a reaction. 
D) a single enzyme typically reacts with many different substrates. 
A) they function in an aqueous environment. 
B) they lower the activation energy of a reaction. 
C) they increase the rate of a reaction. 
D) a single enzyme typically reacts with many different substrates.

Which of the following is true about protein folding?

Which of the following modifications marks a protein for degradation in proteasomes?

Western blotting is a method for detecting:

Which of the following is true about enzymes?

What is the basis for separation of proteins by two-dimensional gel electrophoresis? Why is this better for resolving a mixture of proteins?

You are studying an oligopeptide composed of eight amino acids.The four amino acids nearest the C terminus are nonpolar.The two amino acids nearest the N terminus are charged.The middle two amino acids are polar.Which amino acid is likely to be labeled as number 2?

Which of the following does NOT impose limits on protein folding?

There are many important roles for the dynamic nature of proteins in a cell.Which of the following is NOT likely to describe one such reason?

The correct order for molecular chaperone-mediated protein folding is: I - exchange of ATP for ADP on chaperone II - chaperone undergoes conformational change,which affects protein folding III - chaperone binds to exposed hydrophobic residues on unfolded protein IV - folded protein is released

Changes in the conformational shape of an enzyme that diminish the size of its ligand-binding pocket are likely to affect an enzyme's:

All the following statements about enzymes are true except:

Chemical Foundations

Molecular Genetic Techniques

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

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

Filters

Exam 3: Protein Structure and Function

Which of the following is true about protein folding?

Which of the following modifications marks a protein for degradation in proteasomes?

Western blotting is a method for detecting:

Which of the following is true about enzymes?

What is the basis for separation of proteins by two-dimensional gel electrophoresis? Why is this better for resolving a mixture of proteins?

You are studying an oligopeptide composed of eight amino acids.The four amino acids nearest the C terminus are nonpolar.The two amino acids nearest the N terminus are charged.The middle two amino acids are polar.Which amino acid is likely to be labeled as number 2?

Which of the following does NOT impose limits on protein folding?

There are many important roles for the dynamic nature of proteins in a cell.Which of the following is NOT likely to describe one such reason?

The correct order for molecular chaperone-mediated protein folding is: I - exchange of ATP for ADP on chaperone II - chaperone undergoes conformational change,which affects protein folding III - chaperone binds to exposed hydrophobic residues on unfolded protein IV - folded protein is released

Changes in the conformational shape of an enzyme that diminish the size of its ligand-binding pocket are likely to affect an enzyme's:

All the following statements about enzymes are true except:

Chemical Foundations

Molecular Genetic Techniques

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

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

Filters