Chapter 1 Biochemistry and the Language of Chemistry
1) The water content in the human body is approximately:
A) 90%.
B) 80%.
C) 70%.
D) 60%.
E) 50%.
Answer: C
2) The four most abundant chemical elements in living systems are:
A) hydrogen, oxygen, sulfur and phosphorus.
B) hydrogen, carbon, nitrogen and oxygen.
C) sodium, potassium, carbon and oxygen.
D) sodium, potassium, nitrogen and sulfur.
E) carbon, nitrogen, oxygen and potassium.
Answer: B
Objective: 1.2
3) Nearly all proteins contain:
A) cobalt.
B) phosphorus.
C) selenium.
D) sulfur.
E) none of the above.
Answer: D
Objective: 1.2
Global LO: G7
4) Which of the following statements is FALSE?
A) Proteins can be structural components of cells.
B) Proteins can transmit signals between cells.
C) Proteins can transport molecules within cells and between cells.
D) Proteins can be both hormones and hormone receptors.
E) Proteins are the only biological polymer that can catalyze biochemical reactions.
Answer: E
Objective: 1.2
Global LO: G7
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,5) Which of the following is NOT classed as a lipid?
A) Cholesterol
B) Palmitic acid
C) Glycerol
D) Phosphatidyl serine
E) Triacylglycerol
Answer: C
Objective: 1.2
Global LO: G7
6) Amino acids and simple organic compounds like carbon dioxide and hydrogen cyanide cannot
be produced without the use of enzymes.
Answer: FALSE
Objective: 1.2
Global LO: G7
7) Oxidation-reduction reactions, which are the basis of many biochemical reactions and
pathways, cannot take place in the absence of oxygen.
Answer: FALSE
Objective: 1.2
Global LO: G7
8) Many biochemical reactions that form biopolymers from monomeric units involve the
removal of water.
Answer: TRUE
Objective: 1.2
Global LO: G7
9) The principle component of a biological membrane is a triglyceride.
Answer: FALSE
Objective: 1.2
Global LO: G7
10) The chemical element ________ has a role in both transfer of energy as well as in the
structure of nucleic acids.
Answer: phosphorus
Objective: 1.2
Global LO: G7
11) List the four major classes of biological macromolecules.
Answer: lipids, carbohydrates, proteins, nucleic acids
Objective: 1.2
Global LO: G7
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,12) An amphipathic molecule provides the foundation for biological membranes because they
have both ________ and ________ functional groups.
Answer: hydrophobic, hydrophilic
Objective: 1.2
Global LO: G7
13) Genomics is concerned with the entire ________, while ________ is focused on identifying
all of the proteins of a cell.
Answer: genome, proteomics
Objective: 1.5
Global LO: G1
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,Biochemistry: Concepts and Connections (Appling et al.)
Chapter 2 The Chemical Foundation of Life: Weak Interactions in an Aqueous
Environment
1) Each of the following is a noncovalent interaction EXCEPT:
A) a hydrogen bond.
B) a carbon-hydrogen bond.
C) the interaction between an amino and a carboxylate group.
D) a van der Waals interaction.
E) an interaction between —NH3+ and a water molecule.
Answer: B
Objective: 2.1
Global LO: G7
2) The most important noncovalent interaction in biochemistry is the ________ bond.
Answer: hydrogen
Objective: 2.1
Global LO: G7
3) Which of the following is FALSE when considering van der Waals interactions?
A) The van der Waals radius represents the most stable distance between two interacting centers.
B) Van der Waals radii can determine molecular surfaces.
C) Molecules that interact by van der Waals forces do not interpenetrate.
D) The total interaction energy is the sum of the attractive and repulsive forces.
E) They are not important in determining the stability of three-dimensional structures of proteins.
Answer: E
Objective: 2.2
Global LO: G2
4) Which of the following in biological compounds are sufficiently electronegative to serve as
strong donors in a hydrogen bond?
A) Hydrogen and oxygen
B) Oxygen and nitrogen
C) Nitrogen and hydrogen
D) Hydrogen and carbon
E) Nitrogen and carbon
Answer: B
Objective: 2.2
Global LO: G7
5) Hydrogen bonds share features of both covalent and noncovalent bonds.
Answer: TRUE
Objective: 2.2
Global LO: G2
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, 6) Which of the following is TRUE of hydrophobic molecules?
A) They have limited solubility in water.
B) Water forms a cage-like structure around them.
C) Dissolving in water decreases the entropy of the mixture.
D) They self-associate by releasing some of the surrounding water molecules.
E) All of the above
Answer: E
Objective: 2.3
Global LO: G2
7) Water is both a hydrogen bond donor and acceptor.
Answer: TRUE
Objective: 2.3
Global LO: G2
8) Amphipathic molecules are not able to interact via van der Waals forces.
Answer: FALSE
Objective: 2.3
Global LO: G2
9) Ionic compounds can be readily dissolved in water because the high dielectric constant of
water screens and decreases the ________ force between the oppositely charged ions.
Answer: electrostatic
Objective: 2.3
Global LO: G7
10) The ________ describes the tendency for hydrophobic molecules to aggregate because of the
exclusion of water with the consequent increase of entropy of the solvent.
Answer: hydrophobic effect
Objective: 2.3
Global LO: G7
11) Glycine cannot serve as a buffer because it has two ionizable groups.
Answer: FALSE
Objective: 2.4
Global LO: G7
12) The average charge on an amino acid below its pI will be positive.
Answer: TRUE
Objective: 2.4
Global LO: G2
13) Calculate the acid dissociation constant Ka of a 0.2 M solution of weak acid that is 0.1%
ionized.
Answer: 2 × 10-7
Objective: 2.4
Global LO: G4
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