Amino Acids – Proteins
1-Amino acids are organic compounds containing an amino group [NH2] and an acidic group [COOH] as substituents on the same carbon i.e., the a-carbon. Hence, they are called a-amino acids.
2-Amino acids contain amino (–NH2) and carboxyl (–COOH) functional groups.
3-Amino acids are classified as acidic, basic or neutral depending upon the relative number of amino and carboxyl groups in their molecule.
4-All proteins are polymers of α-amino acids
5-Only α-amino acids are obtained on hydrolysis of proteins.
6-Glycine is so named since it has sweet taste (in Greek glykos means sweet) and tyrosine was first obtained from cheese (in Greek, tyros means cheese.)
7-The amino acids, which can be synthesized in the body, are known as nonessential amino acids.
8- Those which cannot be synthesized in the body and must be obtained through diet, are known as essential amino acids.
9-Amino acids are usually colorless, crystalline solids. These are water-soluble, high melting solids and behave like salts rather than simple amines or carboxylic acids.
Proteins
1-The word protein is derived from Greek word, “proteios” which means primary or of prime importance.
2-Proteins are the most abundant biomolecules of the living system.
3-Proteins are polypeptides.
4-They are also required for growth and maintenance of body.
5-They occur in every part of the body and form the fundamental basis of structure and functions of life.
6-Milk, cheese, pulses, peanuts, fish, meat, etc. are the chief sources of proteins.
7-Dietary proteins are the source of essential amino acids.
8-Each protein is a polymer of amino acids.
9-Ribulose bisphosphate Carboxylase-Oxygenase (RuBisCO) is the most abundant protein in the whole of the biosphere.
10-Collagen is the most abundant protein in animal world.