proteins: amino acids

Question 1

three-dimensional structure

Answer 1

amino acids

Question 2

include an amino group
and a carboxyl group, both of which are bonded to the
a-carbon

Answer 2

amino acid

Question 3

NH2 functional group

Answer 3

amino group

Question 4

—COOH functional
group that disassociates to give the
carboxylate anion, —COO–, and a
hydrogen ion

Answer 4

Carboxyl group

Question 5

Bonded to a hydrogen and to the side chain
group, R

Answer 5

a-carbon

Question 6

Portion of an amino acid that determines its
identity

Answer 6

• Side chain group
• R

Question 7

Two stereoisomers of amino acids are designated
as

Answer 7

L- and D-amino acids based on similarity to
glyceraldehyde

Question 8

Molecules that differ from each other
only in their configuration

Answer 8

Stereoisomers:

Question 9

Alanine

Answer 9

Ala, A

Question 10

Arginine

Answer 10

Arg, R

Question 11

Asparagine

Answer 11

Asn, N

Question 12

Aspartic acid

Answer 12

Asp, D

Question 13

Cysteine

Answer 13

Cys, C

Question 14

Glutamic acid

Answer 14

Glu, E

Question 15

Glutamine

Answer 15

Gln, Q

Question 16

Glycine

Answer 16

Gly, G

Question 17

Histidine

Answer 17

His, H

Question 18

Isoleucine

Answer 18

Ile, I

Question 19

Leucine

Answer 19

Leu, L

Question 20

Lysine

Answer 20

Lys, K

Question 21

Methionine

Answer 21

Met, M

Question 22

Phenylalanine

Answer 22

Phe, F

Question 23

Proline

Answer 23

Pro, P

Question 24

Serine

Answer 24

Ser, S

Question 25

Threonine

Answer 25

Thr, T

Question 26

Tryptophan

Answer 26

Trp, W

Question 27

Tyrosine

Answer 27

Tyr, Y

Question 28

Valine

Answer 28

Val, V

Question 29

Group of amino acids that has non-polar side chains

Answer 29

Glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, and methionine

Question 30

Group of amino acids that has polar side chains

Answer 30

Serine, threonine, tyrosine, cysteine, glutamine, and asparagine

Question 31

Glutamic acid and aspartic acid have

Answer 31

carboxyl groups

Question 32

can lose a proton, forming carboxylate anions

Answer 32

Carboxyl group

Question 33

negatively charged at neutral pH

Answer 33

Side chains

Question 34

Side chain of arginine is a considerably stronger base than an aliphatic amine

Answer 34

Guanidine group

Question 35

attributed to the large resonance stabilization of the protonated form relative to the neutral form

Answer 35

Basicity of the guanidino group

Question 36

Side-chain imidazole group of histidine is a heterocyclic aromatic amine

Answer 36

Imidazole group

Question 37

Amino acids with nonpolar side chains

Answer 37

Alanine, leucine, and phenylalanine

Question 38

Amino acids with basic side chains

Answer 38

Arginine and lysine

Question 39

not in either category because it has a polar side chain

Answer 39

serine