Chapter 6
Biochemistry: The Chemistry of Life
Terms Introduced in This Chapter
After reading Chapter 6, you should be familiar with the following terms. These terms are
defined in Chapter 6 and in the Glossary.
Amino acids
Anticodon
Apoenzyme
Biochemistry
Biologic catalysts
Carbohydrates
Catalyst
Catalyze
Central Dogma
Codon
Coenzyme
Cofactor
Constitutive genes
Covalent bond
Dehydration synthesis reaction
Dipeptide
Disaccharide
DNA nucleotides
DNA polymerase
DNA replication
Double bond
Enzyme
Essential amino acids
Essential fatty acids
Fatty acid
Genetic code
Glucose
Glycosidic bond
Glycogen
Heptose
Hexose
Holoenzyme
Hydrocarbon
Hydrolysis reaction
Inducible genes
Inorganic chemistry
Lipids
Messenger RNA (mRNA)
Monosaccharides
Monounsaturated fatty acid
Nucleic acids
Nucleotides
Organic chemistry
Organic compounds
Pentose
Peptide bond
Phospholipid
Polymer
Polypeptide
Polysaccharide
Polyunsaturated fatty acid
Proteins
Purine
Pyrimidine
Ribosomal RNA (rRNA)
RNA nucleotides
RNA polymerase
Saturated fatty acid
Single bond
Starch
Substrate
Tetrose
Transcription
Transfer RNA (tRNA)
Translation
Triglyceride
Triose
Tripeptide
Triple bond
Waxes
Increase Your Knowledge
Students interested in learning more about the discovery of the structure of DNA should
read The Double Helix, by James D. Watson (Mentor, Penguin Books USA, New York,
1969).
Microbiology—Hollywood Style
Although difficult to find, the 1987 made-for-TV movie, The Race for the Double Helix,
details the events leading up to the discovery of the structure of DNA by James Watson
and Francis Crick. Also portrayed in the film are Maurice Wilkins and Rosalind Franklin.
The role of James Watson was played by Jeff Goldblum.
Critical Thinking
Assume that you are taking an organic chemistry class. Your teacher has given you four
organic compounds to analyze. She tells you that one is a carbohydrate, one is a
hydrocarbon, one is a nucleic acid, and one is a protein.
a.
Compound A contains only carbon and hydrogen. Of the four types of compounds
which were given to you to analyze, which one best describes Compound A?
Compound A is a _______________
b.
You discover that Compound B contains only carbon, hydrogen, and oxygen. Of
the four types of compounds which were given to you to analyze, which one best
describes Compound B?
Compound B is a _______________
c.
You discover that Compound C contains only carbon, hydrogen, oxygen, and
nitrogen. Of the four types of compounds which were given to you to analyze,
which one best describes Compound C?
Compound C is a _______________
d.
You discover that Compound D contains only carbon, hydrogen, oxygen,
nitrogen, and phosphorous. Of the four types of compounds which were given to
you to analyze, which one best describes Compound D?
Compound D is a _______________
Answers to the Chapter 6 Self-Assessment Exercises in
the Text
1.
2.
A
A
3.
4.
5.
6.
7.
8.
9.
10.
C
A
A
D
D
D
D
C
Answers to the Critical Thinking Questions
A.
B.
C.
D.
Hydrocarbon
Carbohydrate
Protein
Nucleic acid
Additional Chapter 6 Self-Assessment Exercises
(Note: Don’t peek at the answers before you attempt to solve these self-assessment exercises.)
Matching Questions
A.
B.
C.
D.
E.
amino acids
disaccharides
fatty acids
monosaccharides
nucleotides
_____ 1.
_______________ are the building
blocks of proteins.
_____ 2.
_______________ consist of a
nitrogenous base, a pentose, and a
phosphate group.
_____ 3.
_______________ are the building
blocks of polysaccharides.
_____ 4.
Sucrose, lactose, and maltose are
examples of _______________.
_____ 5.
Fructose, galactose, and glucose are
examples of _______________.
A.
B.
C.
D.
E.
a dehydration synthesis
reaction
DNA replication
a hydrolysis reaction
transcription
translation
_____ 6.
The end product of _______________ is
a messenger RNA molecule.
_____ 7.
Combining two monosaccharides to
form a disaccharide is an example of
_______________.
_____ 8.
James Watson and Francis Crick were
the first to publish an article describing
_______________.
_____ 9.
The end product of _______________ is
a protein.
_____ 10.
Breaking the bond in a disaccharide to
produce two monosaccharides is an
example of _______________.
True/False Questions
_____ 1.
The covalent bonds that hold monosaccharides together in a polysaccharide are
called glycosidic bonds.
_____ 2.
A DNA nucleotide consists of the following three parts: a nitrogenous base,
ribose, and a phosphate group.
_____ 3.
The waxes in the cell walls of Mycobacterium tuberculosis cause this organism to
be acid-fast.
_____ 4.
The basic structure of a cell membrane is a lipid bilayer.
_____ 5.
DNA polymerase is the only enzyme required for DNA replication.
_____ 6.
Genes that are expressed only when needed are called constitutive genes.
_____ 7.
Polysaccharides, polypeptides, and nucleic acids are all examples of polymers.
_____ 8.
During translation, amino acids are “activated” by attaching to an appropriate
rRNA molecule.
_____ 9.
The peptide bonds that hold amino acids together in protein molecules are
examples of covalent bonds.
_____10.
In double-stranded DNA molecules, the two strands are held together by
hydrogen bonds.
Answers to the Additional Chapter 6 Self-Assessment
Exercises
Matching Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
A
E
D
B
D
D
A
B
E
C
True/False Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
True
False (a DNA nucleotide consists of a nitrogenous base, deoxyribose, and a phosphate
group)
True
True
False (DNA polymerase is the most important enzyme involved in DNA replication, but
other enzymes are also involved)
False (genes that are expressed only when needed are called inducible genes; genes that
are expressed all of the time are called constitutive genes)
True
False (amino acids are “activated” by attaching to an appropriate tRNA molecule)
True
True