Question 1

Which protein signals cellular events?

Accepted Answer

A)  receptor proteins 
B)  structural proteins 
C)  immunoglobulins 
D)  transport proteins 
E)  dietary proteins 
A)  receptor proteins 
B)  structural proteins 
C)  immunoglobulins 
D)  transport proteins 
E)  dietary proteins

Question 2

The following is a description of an enzyme called superoxide dismutase.Refer to this paragraph to answer the following question. Superoxide dismutase is an enzyme that detoxifies a free radical called superoxide.This radical is responsible for causing injury during reperfusion after a heart attack, and is also thought to play a role in Parkinson's Disease.a Depending on what organism the protein is found in, it occurs either as a dimer or tetramer of identical subunits.b The subunits are mostly α-helical with some β-sheet near the C-terminus.c A metal binding site for manganese, iron, nickel or copper/zinc is composed of residues from both the N-terminus and the C-terminus.d These residues are: His-26, His-81, Asp-167, His-171.e
Which statement refers to primary structure?

Accepted Answer

A)  statement a 
B)  statement b 
C)  statement c 
D)  statement d 
E)  statement e 
A)  statement a 
B)  statement b 
C)  statement c 
D)  statement d 
E)  statement e

Question 3

What type of interaction would you expect between the following -R groups in the tertiary structure of a protein?

Accepted Answer

A)  hydrogen bonds 
B)  hydrophobic interactions 
C)  peptide bonds 
D)  disulfide bonds 
E)  salt bridges 
A)  hydrogen bonds 
B)  hydrophobic interactions 
C)  peptide bonds 
D)  disulfide bonds 
E)  salt bridges

Question 4

Which type of protein defends the body against infectious agents?

Accepted Answer

A)  receptors 
B)  structural proteins 
C)  immunoglobulins 
D)  transport proteins 
E)  dietary proteins 
A)  receptors 
B)  structural proteins 
C)  immunoglobulins 
D)  transport proteins 
E)  dietary proteins

Question 5

Select the statement that BEST describes a key difference between competitive and noncompetitive inhibitors.

Accepted Answer

A)  A competitive inhibitor binds to the active site, and a noncompetitive inhibitor does not. 
B)  A noncompetitive inhibitor binds to the active site, and a competitive inhibitor does not. 
C)  A competitive inhibitor is more effective than a noncompetitive inhibitor. 
D)  A noncompetitive inhibitor is more effective than a competitive inhibitor. 
E)  A noncompetitive inhibitor has structural similarities to the enzyme's active site, and the competitive inhibitor does not. 
A)  A competitive inhibitor binds to the active site, and a noncompetitive inhibitor does not. 
B)  A noncompetitive inhibitor binds to the active site, and a competitive inhibitor does not. 
C)  A competitive inhibitor is more effective than a noncompetitive inhibitor. 
D)  A noncompetitive inhibitor is more effective than a competitive inhibitor. 
E)  A noncompetitive inhibitor has structural similarities to the enzyme's active site, and the competitive inhibitor does not.

Question 6

A protein's native conformation is

Accepted Answer

A)  its shape when it is first made. 
B)  its shape when it is not bound to a substrate. 
C)  its three-dimensional shape in which it is biologically active. 
D)  the shape of the protein without any cofactors. 
E)  the amino acid sequence. 
A)  its shape when it is first made. 
B)  its shape when it is not bound to a substrate. 
C)  its three-dimensional shape in which it is biologically active. 
D)  the shape of the protein without any cofactors. 
E)  the amino acid sequence.

Question 7

Acetylcholine is a neurotransmitter that initiates muscle contraction.In order for muscle to relax after contraction, acetylcholine must be broken down into choline and acetate by the enzyme acetylcholinesterase.Nerve agents such as Sarin inhibit acetylcholinesterase by permanently covalently bonding to a serine amino acid in the active site of the enzyme, causing muscle paralysis.What type of inhibitor is Sarin?

Accepted Answer

A)  a competitive, reversible inhibitor 
B)  a noncompetitive, reversible inhibitor 
C)  a competitive, irreversible inhibitor 
D)  a noncompetitive, irreversible inhibitor 
E)  Sarin is not an inhibitor. 
A)  a competitive, reversible inhibitor 
B)  a noncompetitive, reversible inhibitor 
C)  a competitive, irreversible inhibitor 
D)  a noncompetitive, irreversible inhibitor 
E)  Sarin is not an inhibitor.

Question 8

In the peptide Ser-Gly-Asp-Ala, the N-terminal amino acid is

Accepted Answer

A)  aspartic acid. 
B)  alanine. 
C)  cysteine. 
D)  serine. 
E)  glycine. 
A)  aspartic acid. 
B)  alanine. 
C)  cysteine. 
D)  serine. 
E)  glycine.

Question 9

The following is a description of an enzyme called superoxide dismutase.Refer to this paragraph to answer the following question. Superoxide dismutase is an enzyme that detoxifies a free radical called superoxide.This radical is responsible for causing injury during reperfusion after a heart attack, and is also thought to play a role in Parkinson's Disease.a Depending on what organism the protein is found in, it occurs either as a dimer or tetramer of identical subunits.b The subunits are mostly α-helical with some β-sheet near the C-terminus.c A metal binding site for manganese, iron, nickel or copper/zinc is composed of residues from both the N-terminus and the C-terminus.d These residues are: His-26, His-81, Asp-167, His-171.e
Which statement refers to secondary structure?

Accepted Answer

A)  statement a 
B)  statement b 
C)  statement c 
D)  statement d 
E)  statement e 
A)  statement a 
B)  statement b 
C)  statement c 
D)  statement d 
E)  statement e

Question 10

Hemoglobin contains iron.The iron is an example of a(n)

Accepted Answer

A)  cofactor. 
B)  heme. 
C)  enzyme. 
D)  coenzyme. 
E)  metal. 
A)  cofactor. 
B)  heme. 
C)  enzyme. 
D)  coenzyme. 
E)  metal.

Question 11

__________ are catalysts for the reactions of metabolism.

Accepted Answer

A)  Motor proteins 
B)  Immunoglobulins 
C)  Transport proteins 
D)  Enzymes 
E)  Dietary proteins 
A)  Motor proteins 
B)  Immunoglobulins 
C)  Transport proteins 
D)  Enzymes 
E)  Dietary proteins

Question 12

An amino acid zwitterion has

Accepted Answer

A)  a net positive charge. 
B)  a net negative charge. 
C)  a net neutral charge. 
D)  any non-neutral charge. 
E)  Zwitterions can have any charge. 
A)  a net positive charge. 
B)  a net negative charge. 
C)  a net neutral charge. 
D)  any non-neutral charge. 
E)  Zwitterions can have any charge.

Question 13

How many naturally occurring amino acids are there?

Accepted Answer

A)  1 
B)  5 
C)  10 
D)  20 
E)  hundreds 
A)  1 
B)  5 
C)  10 
D)  20 
E)  hundreds

Question 14

In an enzyme-catalyzed reaction, the reactant that the enzyme acts upon is called the

Accepted Answer

A)  prosthetic group. 
B)  substrate. 
C)  coenzyme. 
D)  reagent. 
E)  cofactor. 
A)  prosthetic group. 
B)  substrate. 
C)  coenzyme. 
D)  reagent. 
E)  cofactor.

Question 15

A protein acts as a catalyst if its name ends with

Accepted Answer

A)  -ase. 
B)  -ate. 
C)  -ine. 
D)  -ous. 
E)  -ite. 
A)  -ase. 
B)  -ate. 
C)  -ine. 
D)  -ous. 
E)  -ite.

Question 16

In some proteins, hydrogen bonding occurs between polar residues and the surrounding aqueous environment, forcing the polar residues to the exterior of the protein.What are the interactions between the polar residues and the aqueous environment called?

Accepted Answer

A)  hydrophilic interactions 
B)  salt bridges 
C)  nonpolar interactions 
D)  hydrophobic interactions 
E)  dispersion forces 
A)  hydrophilic interactions 
B)  salt bridges 
C)  nonpolar interactions 
D)  hydrophobic interactions 
E)  dispersion forces

Question 17

Which choice has the BEST labels for this amino acid?

Accepted Answer

A)  1: amino acid 2: carbon 3: side chain 4: alcohol 
B)  1: amide 2: α-carbon 3: R 4.ester 
C)  1: amine 2: side chain 3: α-carbon 4.ester 
D)  1: amide 2: α-carbon 3: side chain 4.carbonyl 
E)  1: amine 2: α-carbon 3: side chain 4.carboxylic acid 
A)  1: amino acid 2: carbon 3: side chain 4: alcohol 
B)  1: amide 2: α-carbon 3: R 4.ester 
C)  1: amine 2: side chain 3: α-carbon 4.ester 
D)  1: amide 2: α-carbon 3: side chain 4.carbonyl 
E)  1: amine 2: α-carbon 3: side chain 4.carboxylic acid

Question 18

Which amino acid has a nonpolar side chain and is achiral?

Accepted Answer

A)  lysine 
B)  glycine 
C)  alanine 
D)  cysteine 
E)  valine 
A)  lysine 
B)  glycine 
C)  alanine 
D)  cysteine 
E)  valine

Question 19

How is the following amino acid classified?

Accepted Answer

A)  nonpolar 
B)  polar neutral 
C)  polar acidic 
D)  polar basic 
E)  None of the above is a correct classification. 
A)  nonpolar 
B)  polar neutral 
C)  polar acidic 
D)  polar basic 
E)  None of the above is a correct classification.

Question 20

Which of the following is NOT common to all peptides?

Accepted Answer

A)  the peptide backbone 
B)  amide functional groups 
C)  peptide bonds 
D)  repeating N   Cα
    C=O units 
E)  an alanine N-terminus 
A)  the peptide backbone 
B)  amide functional groups 
C)  peptide bonds 
D)  repeating N   Cα
    C=O units 
E)  an alanine N-terminus

Which protein signals cellular events?

What type of interaction would you expect between the following -R groups in the tertiary structure of a protein?

Which type of protein defends the body against infectious agents?

Select the statement that BEST describes a key difference between competitive and noncompetitive inhibitors.

A protein's native conformation is

In the peptide Ser-Gly-Asp-Ala, the N-terminal amino acid is

Hemoglobin contains iron.The iron is an example of a(n)

__________ are catalysts for the reactions of metabolism.

An amino acid zwitterion has

How many naturally occurring amino acids are there?

In an enzyme-catalyzed reaction, the reactant that the enzyme acts upon is called the

A protein acts as a catalyst if its name ends with

In some proteins, hydrogen bonding occurs between polar residues and the surrounding aqueous environment, forcing the polar residues to the exterior of the protein.What are the interactions between the polar residues and the aqueous environment called?

Which choice has the BEST labels for this amino acid?

Which amino acid has a nonpolar side chain and is achiral?

How is the following amino acid classified?

Which of the following is NOT common to all peptides?

Matter, Energy, and Measurement

Atomic Structure and Radioisotopes

Ionic and Covalent Compounds

Molecular Geometry, Polarity, and Intermolecular

Chemical Quantities and Introduction to Reactions

Chemical Reactions: Energy, Rates, and Equilibrium

Changes of State and Gas Laws

Mixtures, Solution Concentrations, and Diffusion

Acids and Bases, Ph, and Buffers

Introduction to Organic Chemistry:

Alcohols, Phenols, Thiols, Ethers, and Amines

The Carbonyl Containing Functional Groups

The Common Organic Reactions in Biochemistry

Carbohydrates: Structure and Function

Lipids: Structure and Function

Nucleotides and Nucleic Acids

Energy and Metabolism

Filters

Exam 16: Proteins: Structure and Function

Which protein signals cellular events?

What type of interaction would you expect between the following -R groups in the tertiary structure of a protein?

Which type of protein defends the body against infectious agents?

Select the statement that BEST describes a key difference between competitive and noncompetitive inhibitors.

A protein's native conformation is

In the peptide Ser-Gly-Asp-Ala, the N-terminal amino acid is

Hemoglobin contains iron.The iron is an example of a(n)

__________ are catalysts for the reactions of metabolism.

An amino acid zwitterion has

How many naturally occurring amino acids are there?

In an enzyme-catalyzed reaction, the reactant that the enzyme acts upon is called the

A protein acts as a catalyst if its name ends with

In some proteins, hydrogen bonding occurs between polar residues and the surrounding aqueous environment, forcing the polar residues to the exterior of the protein.What are the interactions between the polar residues and the aqueous environment called?

Which choice has the BEST labels for this amino acid?

Which amino acid has a nonpolar side chain and is achiral?

How is the following amino acid classified?

Which of the following is NOT common to all peptides?

Matter, Energy, and Measurement

Atomic Structure and Radioisotopes

Ionic and Covalent Compounds

Molecular Geometry, Polarity, and Intermolecular

Chemical Quantities and Introduction to Reactions

Chemical Reactions: Energy, Rates, and Equilibrium

Changes of State and Gas Laws

Mixtures, Solution Concentrations, and Diffusion

Acids and Bases, Ph, and Buffers

Introduction to Organic Chemistry:

Alcohols, Phenols, Thiols, Ethers, and Amines

The Carbonyl Containing Functional Groups

The Common Organic Reactions in Biochemistry

Carbohydrates: Structure and Function

Lipids: Structure and Function

Nucleotides and Nucleic Acids

Energy and Metabolism

Filters