Download Practice for Buffers and Amino Acids MULTIPLE

Practice for Buffers and Amino Acids
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) In the following equation which is the proton donor and which is the proton acceptor?
CO3-2 (aq) + H2O (l) → HCO3- (aq) + OH- (aq)
A) Donor: OH-; acceptor: HCO 3B) Donor: CO 3-2; acceptor: H2O
C) Donor: HCO3-; acceptor: OHD) Donor: H2O; acceptor: CO3-2
1)
2) Which of the following is a weak acid?
A) H3PO4
B) NH3
2)
C) HNO 3
3) What is the conjugate acid of HS-?
A) SB) S-2
D) OH3)
C) HS-
D) H2S
4) Which of the following does not represent a conjugate acid-base pair?
A) HC2H3O2/OHB) HCl/ClC) H3O+/H2O
D) HCN/CN5) What is the conjugate acid of NH3?
A) NH4+
B) NH4
4)
5)
C) NH2-
D) NH2+
6) Calculate the pH of 0.00756 M HNO3.
A) 2.121
6)
B) 7.091
C) 11.879
D) 12.947
7) In an acidic solution, pH is ________ and [H3O+] is ________.
A) > 7, < 1 x 10-7 M
C) < 7, > 1 x 10-7 M
7)
B) < 7, < 1 x 10-7 M
D) = 7, 1 x 10-7 M
8) What is the [H3O+] concentration of a solution that has a pH = 2.34?
A) 4.6 × 10 -3 M
B) 1.2 × 10 1 M
C) 2.3 × 10 -3 M
8)
D) 2.2 × 10 -12 M
9) Consider the weak acid HCO3- whose pKa = 10.32, which form will predominate when the pH
9)
of the solution is 8.5?
A) H2CO3
B) HCO3-
C) CO3-2
D) All of these
10) Consider the weak acid HCO3- whose pKa = 10.32, which form will predominate when the pH
10)
of the solution is 12.00?
A) H2CO3
B) CO3-2
C) HCO3-
D) All of these
11) Which of the following buffers is the one that is mainly contained in our blood?
A) H2CO3/HCO3B) HPO4-2/PO4-3
C) NH4+/NH3
D) HC2H3O2/C2H3O21
11)
12) When a person hyperventilates the condition is known as:
A) respiratory alkalosis
B) respiratory acidosis
C) metabolic acidosis
D) metabolic alkalosis
12)
13) When a person does excess vomiting the condition the blood develops is called:
A) metabolic acidosis
B) metabolic alkalosis
C) respiratory acidosis
D) respiratory alkalosis
13)
14) When a diabetic does not have enough glucose in their blood it develops a condition called:
A) metabolic alkalosis
B) metabolic acidosis
C) respiratory acidosis
D) respiratory alkalosis
14)
15) Which of the following represents the zwitterions form of the amino acid valine?
A)
B)
15)
C)
D)
16) What are the three letter and one letter designation for tyrosine?
A) Thr, T
B) Tyr, H
C) Trp, W
17) What type of amino acid is histidine?
A) Nonpolar neutral
C) Basic
16)
D) Tyr, Y
17)
B) Acidic
D) Polar neutral
18) Which of the following amino acids contains sulfur in the side chain?
A) Tyrosine
B) Phenylalanine
C) Glycine
D) Cysteine
19) All amino acids contain a chiral carbon except for one. Which one?
A) Cysteine
B) Histidine
C) Glycine
D) Phenylalanine
20) Which of the following amino acids is classified as being hydrophobic?
A) Cysteine
B) Phenylalanine
C) Histidine
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18)
19)
20)
D) Arginine
21) An essential amino acid is defined as one that:
A) is capable of being synthesized within the human body
B) must be part of the proteins of the food supply of humans
C) occurs in all animal protein
D) occurs in human protein
21)
22) Corn is an incomplete protein because it lacks one or more:
A) essential amino acids
B) amino acids containing sulfur
C) amino acids
D) free amino acids
22)
23) Which is not a characteristic element of proteins?
A) N
B) C
23)
C) H
D) Cl
24) This dipeptide is designated as:
A) Cys-Ser
24)
B) Ser-Lys
C) Ser-Cys
25) Which amino acid is the N-terminal group in the following peptide?
Gly-Ala-Val-Phe-Tyr
A) Val
B) Gly
C) Tyr
26) Which amino acid is the C-terminal group in the following peptide?
Gly-Ala-Val-Phe-Tyr
A) Gly
B) Val
C) Tyr
27) The structure among the following that represents an amide (protein) bond is:
A)
B)
C)
D)
3
D) Lys-Ser
25)
D) Ala
26)
D) Ala
27)
28) What amino acids are involved in the following tripeptide?
A) Lys-His-Phe
B) His-Lys-Phe
C) Tyr-His-Lys
28)
D) Lys-His-Tyr
29) The sequence of amino acid is considered to be the ________ structure of a protein.
A) secondary
B) quaternary
C) tertiary
D) primary
29)
30) The pattern the backbone folds, for example alpha-helix or beta pleated sheet, is the ________
structure of a protein.
A) tertiary
B) primary
C) quaternary
D) secondary
30)
31) The interaction of the side chains on the amino acids, for example hydrophobic attractions, is the
________ structure of a protein.
A) quaternary
B) secondary
C) primary
D) tertiary
31)
32) Which type of forces stabilizes the primary structure of a protein?
A) Hydrogen bonding between the carbonyl group and amino group
B) Dipole-dipole
C) Salt bridges
D) Peptide bonds
32)
33) Which pair of amino acids can have nonpolar (hydrophobic) interactions?
A) Cysteine and cysteine
B) Arginine and glutamate
C) Phenylalanine and valine
D) Tyrosine and serine
33)
34) The alpha-helix is an example of:
A) tertiary structure
C) primary structure
34)
B) quaternary structure
D) secondary structure
35) What type of stabilizing interaction would be expected between phenylalanine and valine?
A) Hydrophobic interaction
B) Salt bridges
C) Disulfide bonds
D) Hydrogen bonds
35)
36) What type of stabilizing interaction could there be between the side chains of glutamic acid and
lysine?
A) Disulfide bonds
B) Hydrogen bonds
C) Salt bridges
D) Hydrophobic interactions
36)
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Answer Key
Testname: 2100BUFFERAMINOACIDS
1) D
2) A
3) D
4) A
5) A
6) A
7) C
8) A
9) A
10) B
11) A
12) A
13) B
14) B
15) C
16) D
17) C
18) D
19) C
20) B
21) B
22) A
23) D
24) A
25) B
26) C
27) B
28) D
29) D
30) D
31) D
32) D
33) C
34) D
35) A
36) C
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