TEST BANK - Lehninger Principles of Biochemistry 8th
Edition By Nelson & Cox
The net charge of the zwitterion form of Gly is ___ - ANSWER: Zero
When a peptide bond is formed, an ___ reacts with a carboxylate group - ANSWER:
Amino Group
At a pH above the pKa, the phenol group of tyrosine is - ANSWER: Deprotonated
In the tripeptide Lys-Pro-Ile, there are ___ charged groups at pH 7 - ANSWER: Three
at a pH below the pKa, the ε-amino group of lysine is - ANSWER: Protonated
at a pH below the pKa, the β-carboxylate group of Asp is ___ - ANSWER: uncharged;
Protonated
In the peptide Trp-Ser-Val, valine is at the - ANSWER: C-terminus
In the tripeptide Trp-Val-Phe, the N-terminal residue is ___ - ANSWER: tryptophan
In the tripeptide Lys-Pro-Ile, the C-terminal residue is - ANSWER: Isoleucine
Biological systems usually produce a single enantiomer, whereas chemical synthesis
produces a ___ - ANSWER: racemic mixture
GABA is a neurotransmitter derived from ___ - ANSWER: glutamate
Glutathione is a tripeptide containing a central ___ residue - ANSWER: Cysteine
In the early 1930's William Rose fed laboratory rats a mixture of all 19 amino acids
known to be present in proteins. He observed that his rats lost weight. This
observation led to the discovery of ____ as the 20th amino acid found in proteins -
ANSWER: Thr
What percentage of the 20 Amino acids is considered to be nutritionally essential to
lab animals? - ANSWER: 50%
About half of the 20 amino acids are called essential because - ANSWER: Our bodies
cannot synthesize them and therefor they need to be present in our diets
Which amino acid does not have a primary α-amino group? - ANSWER: Proline
, Which of the following statements is true?
A) Amino acids can be derived from purines
B) Purines and Pyrimidines can be derived from amino acids
C) Corn contains all 20 standard amino acids
D) Amino acids can be derived from pyrimidines
E) None of the Above - ANSWER: B
Which of the following Amino Acids is the least abundant in proteins?
A) V
B) W
C) G
D) F
E) A - ANSWER: B
Zwitterions are - ANSWER: ions that bear both negatively and positively charged
groups
The formation of a dipeptide from two amino acids involves... - ANSWER: Loss of
water
See #21 and be able to determine a peptide bond - ANSWER: #21
Which of the following amino acids has a charged polar side chain at pH 7.0?
A) Leu
B) Ala
C) Met
D) Trp
E) Glu - ANSWER: E
Which of the following tripeptides carries a NET positive charge at pH 7.0?
A) Ala-Thr-Asn
B) Gln-Val-Ser
C) Arg-Glu-Met
D) Pro-Ile-Leu
E) Leu-Lys-Gly - ANSWER: E
Which of the following amino acids has a sulfur atom in its side chain?
A) Asn
B) Ser
C) Phe
D) Met
E) Tyr - ANSWER: D
Edition By Nelson & Cox
The net charge of the zwitterion form of Gly is ___ - ANSWER: Zero
When a peptide bond is formed, an ___ reacts with a carboxylate group - ANSWER:
Amino Group
At a pH above the pKa, the phenol group of tyrosine is - ANSWER: Deprotonated
In the tripeptide Lys-Pro-Ile, there are ___ charged groups at pH 7 - ANSWER: Three
at a pH below the pKa, the ε-amino group of lysine is - ANSWER: Protonated
at a pH below the pKa, the β-carboxylate group of Asp is ___ - ANSWER: uncharged;
Protonated
In the peptide Trp-Ser-Val, valine is at the - ANSWER: C-terminus
In the tripeptide Trp-Val-Phe, the N-terminal residue is ___ - ANSWER: tryptophan
In the tripeptide Lys-Pro-Ile, the C-terminal residue is - ANSWER: Isoleucine
Biological systems usually produce a single enantiomer, whereas chemical synthesis
produces a ___ - ANSWER: racemic mixture
GABA is a neurotransmitter derived from ___ - ANSWER: glutamate
Glutathione is a tripeptide containing a central ___ residue - ANSWER: Cysteine
In the early 1930's William Rose fed laboratory rats a mixture of all 19 amino acids
known to be present in proteins. He observed that his rats lost weight. This
observation led to the discovery of ____ as the 20th amino acid found in proteins -
ANSWER: Thr
What percentage of the 20 Amino acids is considered to be nutritionally essential to
lab animals? - ANSWER: 50%
About half of the 20 amino acids are called essential because - ANSWER: Our bodies
cannot synthesize them and therefor they need to be present in our diets
Which amino acid does not have a primary α-amino group? - ANSWER: Proline
, Which of the following statements is true?
A) Amino acids can be derived from purines
B) Purines and Pyrimidines can be derived from amino acids
C) Corn contains all 20 standard amino acids
D) Amino acids can be derived from pyrimidines
E) None of the Above - ANSWER: B
Which of the following Amino Acids is the least abundant in proteins?
A) V
B) W
C) G
D) F
E) A - ANSWER: B
Zwitterions are - ANSWER: ions that bear both negatively and positively charged
groups
The formation of a dipeptide from two amino acids involves... - ANSWER: Loss of
water
See #21 and be able to determine a peptide bond - ANSWER: #21
Which of the following amino acids has a charged polar side chain at pH 7.0?
A) Leu
B) Ala
C) Met
D) Trp
E) Glu - ANSWER: E
Which of the following tripeptides carries a NET positive charge at pH 7.0?
A) Ala-Thr-Asn
B) Gln-Val-Ser
C) Arg-Glu-Met
D) Pro-Ile-Leu
E) Leu-Lys-Gly - ANSWER: E
Which of the following amino acids has a sulfur atom in its side chain?
A) Asn
B) Ser
C) Phe
D) Met
E) Tyr - ANSWER: D
