Bmsc 200 - Final Exam Pictures

Question 1

Answer 1

Glycine, Gly, G
Nonpolar, Aliphatic

Only AA to not have a chiral center
Smallest AA
Often found with Proline at polypeptide turns
Uncommon in a-helices due to flexibility
Makes up collagen (Gly-X-Y)

(all NP buried in core)

Question 2

Answer 2

Alanine, Ala, A
Nonpolar, Aliphatic

Question 3

Answer 3

Valine, Val, V
Nonpolar, Aliphatic

Uncommon in a-helices due to side chain branches resulting in steric interference

Question 4

Answer 4

Leucine, Leu, L
Nonpolar, Aliphatic

Question 5

Answer 5

Isoleucine, Ile, I
Nonpolar, Aliphatic

Uncommon in a-helices due to side chain branches resulting in steric interference

Question 6

Answer 6

Proline, Pro, P
Nonpolar, Aliphatic

Often found with Glycine at polypeptide turns
Not found in a-helices due to rigidity
In collagen, (Gly-X-Y), X is often proline

Question 7

Answer 7

Methionine, Met, M
Nonpolar, Aliphatic

One of two AA with a sulfur group in its side chain, although it cannot form disulfide bonds

Question 8

Answer 8

Tyrosine, Tyr, Y
Aromatic

Triprotic
Can be post-translation modified through phosphorylation - has hydroxyl group

Question 9

Answer 9

Phenylalanine, Phe, F
Aromatic

Question 10

Answer 10

Tryptophan, Trp, W
Aromatic

Largest amino acid
Became a popular supplement in the 80s

Question 11

Answer 11

Cysteine, Cys, C
Polar, Uncharged

Triprotic
One of two AA with a sulfur group in its side chain
Can form disulfide bonds due to sulfhydryl groups

Question 12

Answer 12

Asparagine, Asn, N
Polar, Uncharged

Amido group
Uncommon in a-helices due to hydrogen bonding groups near main chain

Question 13

Answer 13

Glutamine, Gln, Q
Polar, Uncharged

Amido group

Question 14

Answer 14

Serine, Ser, S
Polar, Uncharged

Can be phosphorylated due to hydroxyl group
Uncommon in a-helices due to hydrogen bonding groups near main chain

Question 15

Answer 15

Threonine, Thr, T
Polar, Uncharged

Can be phosphorylated due to hydroxyl group
Uncommon in a-helices due to side chain branches causing steric interference

Question 16

Answer 16

Lysine, Lys, K
Polar, Positively Charged

Triprotic
Always carries +1 charge at physiological pH
Found at C terminus on a-helices due to positive charge

Question 17

Answer 17

Arginine, Arg, R
Polar, Positively Charged

Triprotic
Always carries +1 charge at physiological pH
Found at C terminus on a-helices due to positive charge

Question 18

Answer 18

Histidine, His, H
Polar, Positively Charged

Triprotic
Can also be considered an aromatic
Imidazole group has a pKa near physiological pH such that a fraction of histidines will be +1 and the rest will carry net 0
Found at C terminus on a-helices due to positive charge

Question 19

Answer 19

Aspartate, Asp, D
Polar, Negatively Charged

Triprotic
Can be called aspartic acid
Always carries -1 charge at physiological pH
Uncommon in a-helices due to hydrogen bonding groups near main chain
Found at N terminus on a-helices due to negative charge
Carboxyl group on side chain

Question 20

Answer 20

Glutamate, Glu, E
Polar, Negatively Charged

Triprotic
Can be called glutamic acid
Always carries -1 charge at physiological pH
Found at N terminus on a-helices due to negative charge
Responsible for the taste “umami”, also found in monosodium glutamate (MSG)
Carboxyl group on side chain

Question 21

Answer 21

Adenine

Purine
pairs with T in DNA and U in RNA

Question 22

Answer 22

Guanine

Purine
pairs with cytosine

Question 23

Answer 23

Cytosine

pyrimidine
pairs with guanine

Question 24

Answer 24

Uracil

pyrimidine
pairs with adenine in RNA

Question 25

Answer 25

Thymine

pyrimidine
pairs with adenine in DNA

Question 26

Answer 26

Vitamin D

bone formation, get from sunlight
rickets

Question 27

Answer 27

Vitamin A

plays role in vision

Question 28

Answer 28

Vitamin K

blood coagulation

Question 29

Answer 29

Vitamin E

prevents free radicals

Question 30

Answer 30

Ribose

5c sugar
aldose

Question 31

Answer 31

Deoxyribose

5c sugar
aldose

Question 32

Answer 32

Glucose

6c sugar
aldose
OH below

Question 33

Answer 33

Mannose

6c sugar
aldose

Question 34

Answer 34

Galactose

6c sugar
aldose
OH on top

Question 35

Answer 35

Fructose

6c sugar
ketose because carbonyl group is not at end
can be in furan and pyran rings

Question 36

Answer 36

Dihydroxyacetone

Ketose because carbonyl carbon is not at end

Question 37

Answer 37

Glyceraldehyde

Aldose
template molecule for L or D formation
reference is specifically D (on right =D on left =L)

Question 38

Answer 38

explain steps

Step 1: (Acid/Base) Histidine acts as a base to extract proton from
hydroxyl of Ser. This activates the oxygen of the hydroxyl group.
Step 2: (Covalent) Formation of a covalent linkage from the hydroxyl
group of the Ser to the carbonyl carbon of the peptide bond to be
cleaved in the substrate.
Step 3: (Acid/Base) Histidine acts as an acid to donate a proton to the
amine group of peptide bond to be cleaved, this cuts the substrate
peptide into two pieces.

Phase II
Step 1: (Acid/Base) Histidine acts as a base to extract a proton from a
water molecule, activating the oxygen of this molecule.
Step 2: (Covalent) Activated water molecule attacks the point of
covalent linkage between enzyme and substrate.
Step 3: (Acid/Base) Histidine acts as an acid to donate a proton to
reform the hydroxyl group of Ser.