Table 23.4 A m
a and their biological role
A m
a
Structure
Role
I SL
e
O
OH
NH 2
Forms hemoglobin; prevents M
us
L
wasting in debilitated individuals
L
e
NH 2
O
OH
Promotes healing of skin and broken
bones; reduces M
us
L p
R
t breakdown
V
a
L
NH 2
O
OH
Influences brain uptake of other
neurotransmitter precursors (T ryp
N ,
phenylalanine and tyrosine)
H IS
td
NH 2
HN
N
O
OH
Produces red and white blood cells;
used in the treatment of anemia
Lysine
NH 2
H 2 N
O
OH
Inhibits viruses; used in the
treatment of herpes simplex; Lysine
and vitamin (V
i
T )-c together form Lcarnitine: a biochemical that enables
M
us
L tissue to use oxygen more
efficiently, delaying fatigue
Methionine
NH 2
S
O
OH
Increases the antioxidant levels
(glutathione) and reduces blood
cholesterol level`
Phenylalanine
NH 2
O
OH
Produces collagen, it acts as
precursor of tyrosine; enhances
learning, memory, mood and
alertness
(continued)
23 Protein and Enzymes Isolated from Plant Sources …
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