Biosynthesis of Sulphur Containing amino acid such as Methionine and cysteine are presented with well structured flowsheet.

2. SULPHUR CONTAINING AMINO ACID
1) Methionine
2) Cysteine
3) Homocysteine
4) Taurine
But only two are incorporated in the
protein structures.

3. METHIONINE
Structure of Methionine
 Essential Amino Acid
 It serves as the precursor
for the synthesis of cysteine
and cystine.
 Initiating amino acid in the
Synthesis of eukaryotic
proteins.
 Found in Meat, Fish and
Dairy Products.
 Used to prevent liver
damage in acetaminophen
(Tylenol) poisoning.

4. Biosynthesi
s of
Methionine

5. CYSTEINE
Structure of
Cysteine
 Non-essential, glycogenic
amino acid.
 In mammals , it arises from
methionine and in bacteria
& plant, arises from serine.
 Important for Protein
synthesis , detoxification.
 Glutathione and Co-enzyme
A are derived from cysteine.
 Important constituent of
Sceleroproteins. Example.,
Keratin of hair, nails.

6. Biosynthesi
s of
Cysteine
( In Bacteria
and Plants)

7. Biosynthesi
s of
Cysteine
(In
Mammals)