Amino Acids,Peptides, & Proteins

Question 1

molecules that contain two functional groups: an amino group and a carboxyl group

Answer 1

Amino Acids

Question 2

20 alpha-amino acids

Answer 2

proteinogenic amino acids

Question 3

has hydrogen atom as its R group, making it achiral

Answer 3

Glycine

Question 4

only amino acid that has a R configuration

Answer 4

Cysteine

Question 5

glycine, alanine, valine, leucine, isoleucine, methionine, and proline

Answer 5

nonpolar, nonaromatic side chains

Question 6

one of two sulfur containing AA, methyl group attached to sulfur

Answer 6

methionine

Question 7

tryptophan, phenylalanine, and tyrosine

Answer 7

aromatic side chains

Question 8

add an -OH to phenylalanine

Answer 8

Tyrosine

Question 9

serine, threonine, asparagine, glutamine, cysteine

Answer 9

Polar side chains

Question 10

aspartic acid (aspartate) and glutamic acid (glutamate)

Answer 10

acidic side chains

Question 11

arginine, lysine, and histidine

Answer 11

basic side chains

Question 12

Ala (A)

Answer 12

Alanine

Question 13

Arg (R)

Answer 13

Arginine

Question 14

Asn (N)

Answer 14

Asparagine

Question 15

Asp (D)

Answer 15

Aspartic acid

Question 16

Cys (C)

Answer 16

Cysteine

Question 17

Glu (E)

Answer 17

Glutamic acid

Question 18

Gln (Q)

Answer 18

Glutamine

Question 19

Gly (G)

Answer 19

Glycine

Question 20

His (H)

Answer 20

Histidine

Question 21

Ile (I)

Answer 21

Isoleucine

Question 22

Leu (L)

Answer 22

Leucine

Question 23

Met (M)

Answer 23

Methionine

Question 24

Phe (F)

Answer 24

Phenylalanine

Question 25

Pro (P)

Answer 25

Proline

Question 26

Ser (S)

Answer 26

Serine

Question 27

Thr (T)

Answer 27

Threonine

Question 28

Trp (W)

Answer 28

Tryptophan

Question 29

Tyr (Y)

Answer 29

Tyrosine

Question 30

Val (V)

Answer 30

Valine

Question 31

Lys (K)

Answer 31

Lysine

Question 32

can either accept a proton or donate a proton: how they react depends on the pH of their environment

Answer 32

amphoteric species

Question 33

a majority of the species will be protonated

Answer 33

pH < pKa

Question 34

a majority of the species will be deprotonated

Answer 34

pH > pKa

Question 35

solution acts as a buffer

Answer 35

pH of solution id approximately equal to pKa

Question 36

calculated as the average of two nearest pKa values

point at which every molecule is electrically neutral

Answer 36

pI isolectric point

Question 37

peptide bond formation is an example of

Answer 37

condensation/dehydration reaction

Question 38

linear arrangement of amino acids coded in an organism’s DNA, stabilized by the formation of covalent peptide bonds between adjacent AA

Answer 38

primary structure of protein

Question 39

two main structures are alpha-helices and beta-pleated sheets, stabilized by intramolecular hydrogen bonding

Answer 39

secondary structure

Question 40

stabilized by intramolecular hydrogen bonding between carbonyl oxygen and amide hydrogen atom four residues down

Answer 40

alpha-helix

Question 41

intramolecular hydrogen bonding between carbonyl oxygen atoms on one chain and amide hydrogen atoms in adjacent cahin

Answer 41

beta-pleated sheet

Question 42

mostly determined by hydrophillic and hydrophobic interactions between R groups of AA

Answer 42

tertiary structure of protein

Question 43

important component of tertiary structure and creates loops in protein chain

Answer 43

disulfide bonds

Question 44

proteins that contain more than one polypeptide chain

Answer 44

quarternary structure