Dr C Mercy Assistant professor PG Department of

Dr. C. Mercy, Assistant professor, PG Department of zoology, Sarah Tucker College, Tirunelveli.

PROTEINS

CONTENT �INTRODUCTION �STRUCTURE OF PROTEINS �SHAPE OF PROTEINS �CLASSIFICATION OF PROTEINS �BIOLOGICALS OF ROLES PROTEINS �FUNCTION OF PROTEINS �CONCLUSION

introduction �Protein is a macromolecules composed of one or more polypeptide chains possessing a characteristic amino acid sequence. It is a polymer of amino acids. It is the body builder. �The term protein was first proposed by Berzelius �Haemoglobin, myosin, actin, albumin, gl obulin, are important proteins.

STRUCTURE OF PROTEINS �Protein are polypeptides with more than 100 amino acid residues. �Protein are polymer of amino acid monomers. The amino acid are linked together to form a chain called peptide chain. �It is four types; �Dipeptide �Tripeptide �Oligopeptide �polypeptide

Structure of protein

types �Dipeptide; � It is 2 amino acid resides. �Tripeptide; � It is 3 amino acid monomers. �Oligopeptide; � It is made up less than 10 amino acid. �Polypeptide; � it is made up more than 10 amino acid.

Chemical bond structure �Protein are the polymer of amino acid monomer. Any two amino acid monomer are linked together by chemical bonds. �They are 5 types �PEPTIDE BONDS �DISULFIDE BONDS �HYDROGEN BONDS �NONPOLAR BONDS �IONIC BONDS

CONTINUE �Peptide bonds; �it is amide bond c-atom of coo. H group one amino acid N-atom of NH 2 group. �Disulfides bonds; � it is a covalent bridge two polypeptide chains a cystine residue. �Hydrogen bonds; � it is single atom two electro negative atom. It is weak bond. It is low energy bond.

Conti…. �NONPOLAR BONDS; � it is nonpoler group with aqueous system is bonds. �Ionic bonds; � it is formed ionisation. it is transfer one atom to another. �-coo—mg=ooc- -NH 3 -OOC-

SHAPES OF PROTEINS �Protein are either fibrous or globular. �The fibrous protein are in the from of long fibres. The are formed one or more polypeptide chains. �The globular protein are spherical in shape. They are made up one or more polypeptide chains.

Classification of proteins � On the basis of their solubility and shape � On the basis of increasing complexity of structure.

On the basis solubility and shape �It is 2 group � � globular proteins fibrous proteins �GLOBULAR PROTEINS; � It is spherical shape, soluble in water examble, enzymes, antibodies. �FIBROUS PROTEINS; � It is insoluble in water the are fibre. the are linear molecules.

On the basis increasing complexity of structure �It is 3 groups; � � � simple proteins conjugated proteins derived proteins �Simple proteins; � it is amino acids. The are 7 sub types �Albumins; � it is insoluble in water. The are coagulated by heat. E. Xserum albumin of blood. .

Conti…. �Globulins; � it is insoluble in water , the are coagulated by heat. ex. serum globulin. �Glutelines; � it is insoluble in water, the are coagulated by heat. ex glutelin in wheat. �Prolamines; � it is soluble in 70 to 80 ethyl alcohol. Ex. zein.

Conti… �Histones; � soluble in water by insoluble in ammonia. ex. salmon sperm �Albuminoids; � it is insoluble in water. ex keratin in hair �Protamines; � it is soluble in water. ex. sturine

Conti… �It is non-proteins substances. it is 5 sub types �Glycoprotein; � it carbohydrates as prosthetic group. ex. egg albumin. �Phosphoproteins; � it is phosphoric acids. ex. vitellin in egg yolk. �Lipoproteins; � it is phospholipides. ex. lipoprotein in blood serum.

Conti… �Nucleoproteins; � it is nucleic acid. ex. Nucleohistone etc. �Chromoproteins; � it is coloured proteins. ex. haemoglobin. �Derived proteins; � it intermediate produce natural protein. It is 2 types �Primary derived proteins; � it is derivatives of protein the size. It is 3 types

Conti…. �Proteans; � it is denatured proteins. They are insoluble in water. ex. fibrin derived fibrinogen. �Metaproteins; �it s action of acid or alkali on protein. �Coagulated protein; � it is insoluble produced of heat or alcohol. �Derived secondary protein; � it is original protein. They are 3 sub types

Conti… �Proteoses; � they are soluble in water. It is not coagulated by heat. �Peptones; � it soluble water they are not coagulated by heat. �Polypeptides; � it containing many amino acid units.

Biological roles �They are intermediates in the formation of protein. �They appear as constituents group called alkaloids. �Antibacterial present fungi , bacteria. Penicillin G is common antibiotics. �Certain peptide growth factors. Folic acid, soluble vitamin peptide growth factor for microorganisms. �Higher animals synthesize peptide as hormones.

Function of proteins �All the enzymes are nothing but proteins. All the are catalysed by enzymes. �Protein transport ions and small molecules. �Certain protein function as storage �Ex. Seed store nutrient protein. �Certain protein function as nutrients. ex. egg contains ovalbumin �Many hormones are protein. ex. insulin, growth hormone, parathyroid hormones

conclusion � Protein is a body builder. It is importance of body haemoglobin, myoglobi n, myosin, actin, albumin, globumin, are important