Amino acids

Question 1

Which are non-polar?

Answer 1

Glycine (Gly, G) - H
Alanine (Ala, A) - CH3
Valine (Val, V) - CH connecting to 2 CH3
Leucine (Leu, L) - CH2 connecting to CH to 2 CH3
Isoleucine (Ile, I) - CH connecting to one CH3 and one CH2 which is connecting a CH3
Methionine (Met, M) - CH2 connecting to CH2 connecting to S then connecting to CH3
Proline (Pro, P) - 3 CH2’s - in a ring - one connects to N and one to C
Phenylalanine (Phe, F) - CH2 then benzene ring
Tryptophan (Trp, W) - 5 sided ring containing nitrogen which is fused with a benzene ring

Question 2

Which are polar?

Answer 2

Asparagine (Asn, N) - CH2 connected to a C which has a double bonded O and an amine group
Glutamine (Gln, Q) - CH2 connected to CH2 connected to a C which has a double bonded O and an amine group
Cysteine (Cys, C) - CH2 connected to SH
Serine (Ser, S) - CH2 connected to OH
Threonine (Thr, T) - CH connecting an OH and a CH3
Tyrosine (Tyr, Y) - CH2 connected to a benzene ring connecting an OH

Question 3

What are the polar positively charged?

Answer 3

Lysine (Lys, K) - 4 CH2’s and a NH3+
Arginine (Arg, R) - 3 CH2’s connecting a NH connecting a C which has a NH2 and a NH2+ (double bonded)
Histidine (His, H) - a CH2 connected to a ring with C = CH - NH+ = CH = NH

Question 4

What are the polar negatively charged?

Answer 4

Aspartic acid (Asp, D) - CH2 and a COO-
Glutamic acid (Glu, E) - CH2 connecting a CH2 connecting COO-