18 MHR • Unit 1 Metabolic Processes
Figure 1.14BNotice that each amino acid has an amine at one end and a carboxyl
group at the other.C
H
H
C
O
electrically chargedpolarnon-polarH 3 N+CH 3
O−C
H
C
O
H 3 N+
O−
CH
CH 3 CH 3C
H
C
O
H 3 N+
O−C
H
CH
CH 3CH 2CH 3C
O
H 3 N+
O−C
H
CHCH 2CH 3C
O
H 3 N+
O−H 2 CH 3 CNH 3 +glycine alanine
valineleucine isoleucineC
H
CH 2CH 2SCH 3C
O
H 3 N+
O−C
H
CH 2CH 2CH 2CH 2C
O
H 3 N+
O−methionineC
H
OHCH 2C
O
H 3 N+
O−serineCH
OH CH 3C
H
C
O
H 3 N+
O−threonineC
H
SHCH 2C
O
H 3 N+
O−cysteineC
H
CH 2C
O
H 3 N+
O−phenylalanineOC
H
C
O
H 3 N+
O−NH 2
asparagineCH 2COC
H
C
O
H 3 N+
O−aspartic acidCH 2
CglutamineOC
H
C
O
H 3 N+
O−NH 2CH 2CH 2Cglutamic acidacidiclysineC NH 2 +C
H
CH 2CH 2CH 2NHNH 2C
O
H 3 N+
O−arginineOC
H
C
O
H 3 N+
O−
CH 2
CH 2CtyrosineC
H
CH 2OHC
O
H 3 N+
O−C
H
CH 2C
O
H 3 N+
O−C
H
CH 2
CH 2C
O
H 3 N+
O−tryptophanproline
NHC
H
CH 2C
O
H 3 N+
O−histidineNH
NH+basicO−O−The 20 major amino acids, the subunits for proteins. Notice
that each amino acid has one carbon that is bonded to
both an amino group and a carboxyl group. Notice also that
bonded to this same carbon atom is a molecular group thatis highlighted in colour. Biologists refer to this group as a
side-chain or an R-group. The R-group is different for each
amino acid, and is responsible for its chemical properties.