Notes for Pharmacy competitive examination-1 (Essential Amino acids)

Essential Amino acids- cannot be synthesized  by the organism ,therefore must be supplied in its diet.

Methionine- α-amino acid with the chemical formula HO₂CCH(NH₂)CH₂CH₂SCH₃.This amino-acid is coded by the initiation codon AUG which indicates mRNA's coding region where translation into protein begins. Together with cysteine, methionine is one of two sulfur-containing proteinogenic amino acids

Threonine- α-amino acid with the chemical formula HO₂CCH(NH₂)CH(OH)CH₃serine, threonine is one of two proteinogenic amino acids bearing an alcohol group

Leucine- branched-chain α-amino acid with the chemical formula HO₂CCH(NH₂)CH₂CH(CH₃)₂

Isoleucine- α-amino acid, hydrophobic amino acid, Together with threonine, isoleucine is one of two common amino acids that have a chiral side chain. Four stereoisomers of isoleucine are possible

Tryptophan- genetic code as the codon UGG L-stereoisomer of tryptophan is used in structural or enzyme proteins indole functional group.

Valine- α-amino acid, nonpolar, Along with leucine and isoleucine, valine is a branched-chain amino acid. It is named after the plant valerian. In sickle-cell disease, valine substitutes for the hydrophilic amino acid glutamic acid in hemoglobin. Because valine is hydrophobic, the hemoglobin is prone to abnormal aggregation.

Lysine- α-amino acid, HO₂CCH(NH₂)(CH₂)₄NH₂ , codons are AAA and AAG. Lysine is a base, as are arginine and histidine.

Phenyl alanine- α-amino acid, C₆H₅CH₂CH(NH₂)COOH, nonpolar because of the hydrophobic nature of the benzyl side chain. Phenylalanine is a precursor for tyrosine, the monoamine signaling molecules dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the skin pigment melanin. It is a direct precursor to the neuromodulator phenylethylamine, a commonly used dietary supplement.