Amino Acids and peptides

Question 0

Carbon in which all four groups attached are different

Answer 0

Chiral carbon

Question 1

Amino acid and carboxylic group attach in the same alpha carbon

Answer 1

Alpha amino acids

Question 2

All amino acids have chiral carbon except

Answer 2

Glycine

Question 3

Absolute configuration of amino acids

Answer 3

Glyceraldehyde

Question 4

Configuration of all amino acids derived from natural proteins

Answer 4

L configuration

Question 5

Total number of amino acids in all forms of life

Answer 5

20

Question 6

Amino acids with aliphatic side chain

Answer 6

Leucine, isoleucine, valine, alanine, glycine

Question 7

Amino acids with side chains containing -OH groups

Answer 7

Threonine, tyrosine, serine

Question 8

Amino acids containing side chains with sulfur atoms

Answer 8

Cystein, methionine

Question 9

Amino acids with side chains containing acidic/amide groups

Answer 9

Aspartate, asparagine, glutamate, glutamine

Question 10

Amino acids with side chains containing basic groups

Answer 10

Lysine, histidine, arginine

Question 11

Amino acids containing side chains with aromatic rings

Answer 11

Tryptophan, histidine, phenylalanine, tyrosine

Question 12

Imino acid

Answer 12

Proline

Question 13

Ala (A)

Answer 13

Alanine

Question 14

Arg (R)

Answer 14

Arginine

Question 15

Asp (D)

Answer 15

Aspartate

Question 16

Asn (N)

Answer 16

Asparagine

Question 17

Cys (C)

Answer 17

Cysteine

Question 18

Glu (E)

Answer 18

Glutamate

Question 19

Gly (g)

Answer 19

Glycine

Question 20

His (H)

Answer 20

Histidine

Question 21

Ile (I)

Answer 21

Isoleucine

Question 22

Lys (K)

Answer 22

Lysine

Question 23

Met (M)

Answer 23

Methionine

Question 24

Phe (P)

Answer 24

Phenylalanine

Question 25

Pro (O)

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

Essential amino acids

Answer 31

Phe, val, thr, trp, ile, met, his, leu, lys | Pneumonics: PriVaTe TIM HeLL

Question 32

Non-essential amino acids

Answer 32

Glu, asp, asn, ala | Pneumonics: GAAA

Question 33

Conditional amino acids

Answer 33

Gln, pro, arg, ser, tyr, cys, gly

Question 34

Referred to as 21st amino acid

Answer 34

Selenocysteine

Question 35

Atom that replaced sulfur of cysteine to turn it into selenocysteine

Answer 35

Selenium

Question 36

Which is stronger, R-COOH or R-NH3+?

Answer 36

R-COOH

Question 37

Determined by the pH at which the protonated and unprotonated species is present in equal concentration

Answer 37

pK of an acid

Question 38

Amino acid molecule that has no net charge

Answer 38

Zwitterions

Question 39

T/F? Net charge of amino acids depends upon the pH of the surrounding solution.

Answer 39

True

Question 40

T/f? Functional groups present on amino acids has the same pKa values.

Answer 40

False

Question 41

PH at which an amino acid bears no net charge

Answer 41

Isoelectric pH

Question 42

T/f? Varying the pH of the medium does not alter the cgarhe of the amino acids.

Answer 42

False

Question 43

Charge of amino acid at pH < pI

Answer 43

Positive

Question 44

Charge of amino acid at pH > pI

Answer 44

Negative

Question 45

General properties of amino acid

Answer 45

Soluble in polar solvent, insoluble in non polar solvent, high melting point, do not absorb visible light except aromatics

Question 46

T/f? Specific properties of the amino acids are dictated by the nature of their R groups

Answer 46

True

Question 47

Smallest amino acids allowing it to fit in regions that are inaccessible to other amino acids

Answer 47

Glycine

Question 48

Hydrophobic and occurs in the interior of proteins

Answer 48

Amino acids with aliphatic/aromatic R group

Question 49

Nucleophile, functions as such during enzymatic catalysis

Answer 49

-OH of ser and -SH of cys

Question 50

Undergoes phosphorylation which regulates enzyme activity

Answer 50

-OH of ser, tyr, thr

Question 51

Functions as either a base or acid catalyst at neutral pH

Answer 51

Imidazole group of his

Question 52

Used in detecting a.a. that forms aurple product with alpha a.a. and yellow with imine groups of proline

Answer 52

Ninhydrin

Question 53

Consist of 2 or more a.a. residues linked by peptide bond

Answer 53

Peptides

Question 54

Exhibits partial double bond character

Answer 54

Peptide bond

Question 55

Sample treatment with CuSO4 | Color: purple

Answer 55

Biuret test

Question 56

T/f? Formation of peptides from amino acids is accompanied by a net loss of one positive and one negative charge per peptide bond formed.

Answer 56

True

Question 57

T/f? Peptides are uncharged at physiologic pH because of their terminal carboxyl and amino groups and when present the charger R group

Answer 57

False, charged

Question 58

T/f? pKa values of functional groups will not depend upon its location within a given protein

Answer 58

False, depend

Question 59

Smooth muscle hypotensive agent liberated from specific plasma proteins

Answer 59

Bradykinin

Question 60

Polypeptide antibiotics

Answer 60

Gramicidin

Question 61

Participates in the formation of correct disulfide bonds of many proteins

Answer 61

Glutathione

Question 62

Artificial sweetene

Answer 62

Aspartame