University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

172

Pages:

5
Author:

Sheha A.

Amino Acids Amino acids are a group of organic compounds having both amino groups and carboxyl groups. Amino acids are the building blocks (monomeric units) of peptides and protein which are bonded by peptide bonds. Peptides and Proteins: Peptides and proteins are polymers of amino acids bonded by peptide bonds. Difference between peptides and protein: The difference is based on the number of amino acids present in the chain. Peptides: If the chain contains 2-10 amino acids then it is called peptides. Peptides are of 2 types: Oligopeptides: If the chain contains 2-10 amino acids then it is called a dipeptide. Poly peptides: If the chain contains 11-50 amino acids then it is called a protein. Peptide Bonds: Peptide bond is responsible for the formation of peptides and protein. It is formed between two amino acids, i.e., carboxyl group of the first amino acid and amino group of the next amino acid. Number of peptide bonds are one less than the number of amino acid residues in the chain. For example: Dipeptides have 2 amino acids and 1 peptide bond. Tripeptides have 3 amino acids and 2 peptide bonds. Protein Amino Acids The amino acids that are found in the protein are called protein amino acids. These are two types: a) Primary protein amino acid b) Secondary protein amino acid Primary Protein Amino Acid / Standard Amino Acid Amino acids that are not incorporated into the protein structure during the stages of translation are called primary protein amino acid. Only Primary Protein Amino Acids are Represented by Genetic Code Example: Glycine, Alanine, Tryptophan, etc. Secondary Protein Amino Acids Post-translationally modified amino acids are called Secondary protein amino acids. These amino acids are formed from primary protein amino acids after the stages of translation by post-translational modification. These are not represented by genetic code. Example: Hydroxyproline, Hydroxylysine, Cystine, etc. Non-Protein Amino Acids Amino acids that are not found in the protein are called Non-protein amino acids. Example: Ornithine, Citrulline, γ-aminobutyric acid, Taurine, etc.