Key Concepts - Week 3 - amino acids & peptides

Question 1

Key concepts: Describe amino acid structure and properties

Answer 1

An amino acid is an organic molecule that is made up of a basic amino group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to each amino acid. The term amino acid is short for α-amino [alpha-amino] carboxylic acid

Question 2

Key concepts: describe acid-base properties and charge of amino acids

Answer 2

An amino acid has both a basic amine group and an acidic carboxylic acid group. There is an internal transfer of a hydrogen ion from the -COOH group to the -NH2 group to leave an ion with both a negative charge and a positive charge. This is called a zwitterion

Question 3

Key concepts: describe polymerisation of amino acids

Answer 3

The process of polymerisation of amino acids to form a polypeptide chain is called translation. During the translation process, the genetic information stored in mRNA directs the order of amino acids to form a polypeptide chain. Ribosomes along with tRNA also participate in the process of translation.

Question 4

Key concepts: describe peptide and protein folding and structure

Answer 4

Protein structures are made by condensation of amino acids forming peptide bonds. The sequence of amino acids in a protein is called its primary structure. The secondary structure is determined by the dihedral angles of the peptide bonds, the tertiary structure by the folding of protein chains in space