Proteins

Proteins, classification and functions

1. BIOCHEMISTRY Chapter # 21 XII FDC Prepared by: Sidra Javed

2. PROTEINS Prepared by: Sidra Javed

3. PROTEINS The Molecules which yields amino acids upon hydrolysis are called proteins. Proteins are natural polymer of amino acids. The number of amino acids in a protein molecule may range from two to several thousands. Protein molecules contain Nitrogen, Carbon, Hydrogen and Oxygen. Prepared by: Sidra Javed

4. PROTEINS Proteins are the basis for the major structural components of animal and human tissue. They act as biological catalysts (Enzymes), form structural parts of organisms, participate in different cell reactions, act as molecules of immunity and also provide fuel. Prepared by: Sidra Javed

5. CLASSIFICATION OF PROTEINS Prepared by: Sidra Javed

6. (a) SIMPLE PROTEINS - Albumins Blood ( Serumbumin ) Milk ( Lactalbumin ) Egg White ( Ovolbumin ) Lentils ( Legumelin ) Kidney Beans ( Phaseolin ) Wheat ( Leucosin ) Prepared by: Sidra Javed

7. Globular protein is insoluble in water and dilute salt solution. Precipitated by saturation with (NH 4 ) 2 SO 4 solution. Coagulated by heat. Found in plant and animal tissue. (a) Simple Proteins - Albumins Prepared by: Sidra Javed

8. (a) Simple Proteins - Globulins Blood (Serum Globulins) Muscles (Myosin) Potato ( Tuberin ) Brazil Nuts ( Excelsin ) Hemp ( Edestin ) Lentils ( Legumin ) Prepared by: Sidra Javed

9. Globular Protein is sparingly soluble in water and neutral solutions. Precipitated by dilute Ammonium Sulphate . Coagulated by Heat. Distributed in both plant and animal tissues. (a) Simple Proteins - Globulins Prepared by: Sidra Javed

10. (a) Simple Proteins - Glutelins Wheat ( Glutenin ) Rice ( Oryzenin ) Prepared by: Sidra Javed

11. Insoluble in water and dilute salt solutions. Soluble in dilute acids. Found in grains & cereals. (a) Simple Proteins - Glutelins Prepared by: Sidra Javed

12. Thymus Gland, Pancrease and Nucleoproteins ( Nucleohistones ). Soluble in water, salt solutions & dilute acids. Insoluble in Ammonium Hydroxide. Yeilds large amount of Lysine & arginine . Combined with nucleic acids within cells. (a) Simple Proteins - Histones Prepared by: Sidra Javed

13. Thymus Gland, Pancrease and Nucleoproteins ( Nucleohistones ). Soluble in water, salt solutions & dilute acids. Insoluble in Ammonium Hydroxide. Yeilds large amount of Lysine & arginine . Combined with nucleic acids within cells. (a) Simple Proteins - Histones Prepared by: Sidra Javed

14. Connective tissues and hard tissues. Fibrous protein is insoluble in all solvents. Resistant to digestion. (a) Simple Proteins - Scleroproteins Prepared by: Sidra Javed

15. (a) Conjugated Proteins - Nucleoproteins Cytoplasm of Cells ( Ribonucleoprotein ) Nucleus of Chromosomes & Ribosomes ( Deoxyribonucleoprotein ) Viruses & Bacteriophage Prepared by: Sidra Javed

16. It contains nucleic acids, nitrogen and phosphorus. It is present in chromosomes and in all living forms as a combination of protein with either DNA or RNA. (a) Conjugated Proteins - Nucleoproteins Prepared by: Sidra Javed

17. (b) Conjugated Proteins - Mucoprotein Saliva ( Mucin ) and Egg white ( Ovomucoid ). Proteins combined with amino sugars, sugar acids and sulfates. Prepared by: Sidra Javed

18. (b) Conjugated Proteins - Glycoproteins Bones ( Osseomucoid ), Tendons ( Tendomucoid ) and Cartilage ( Chondromucoid ). Containing more than 4% Hexosamine , mucoproteins ; if less than 4%, then Glycoproteins . Prepared by: Sidra Javed

19. (b) Conjugated Proteins – Phosphoproteins Milk (Casein) and Egg yolk ( Ovovitellin ). Phosphoric acid joined in ester linkage to protein. Prepared by: Sidra Javed

20. (c) Derived Proteins - Proteans Edestan ( from Elastin ) and Myosin (Myosin). It results from short action of acids or enzymes Insoluble in water. Prepared by: Sidra Javed

21. (c) Derived Proteins - Proteases Intermediate product of protein digestion Soluble in water. Not coagulated by heat. Precipitated by saturated ammonium sulphate Result from a partial digestion of protein by pepsin or trypsin . Prepared by: Sidra Javed

22. (c) Derived Proteins -Peptones Intermediate product of protein digestion Same properties as proteases except that they cannot be salted out. Smaller molecular weight than proteases. Prepared by: Sidra Javed

23. (c) Derived Proteins - Peptides Intermediate product of protein digestion Two or more amino acids joined by a peptide linkage. Hydrolyzed to individual amino acids. Prepared by: Sidra Javed

24. STRUCTURE OF PROTEINS Depends upon the spatial arrangement of polypeptide chains. Three arrangements are possible. Four structures: Primary structure Secondary structure Tertiary Structure Quaternary Structure Prepared by: Sidra Javed

25. The Primary Structure Of Proteins The sequence of amino acids in a polypeptide chain is called a primary structure. Amino Acids are linked with one another through peptide bonds. Prepared by: Sidra Javed

26. The Primary Structure Of Proteins Prepared by: Sidra Javed

27. The Secondary Structure Of Proteins Peptide chains may acquire spiral shape or may be present in a zig zig manner. This coiling of peptide chains is called the secondary structure of proteins. It is due to Hydrogen bonding. Prepared by: Sidra Javed

28. The Secondary Structure Of Proteins Prepared by: Sidra Javed

29. The Tertiary Structure Of Proteins Twisting or folding of polypeptide chains represents tertiary structure of proteins. Prepared by: Sidra Javed

30. The Quaternary Structure Of Proteins Quaternary means four. It is the arrangement of multiple folded protein or coiling protein molecules in a multi-subunit complex. A variety of bonding interactions including Hydrogen bonding, salt bridges and disulfide bonds holds the various chains into a particular geometry. Prepared by: Sidra Javed

31. The Quaternary Structure Of Proteins Prepared by: Sidra Javed

32. Prepared by: Sidra Javed

33. Properties Of Proteins Found in all living organisms. Involved in processes such as digestion of food, cell structure, catalysis, movement, energy manipulation etc. Complex molecules. Polymers of amino acids. Long chains of amino acids are called Polypeptides. Prepared by: Sidra Javed

34. Importance of Proteins Proteins play an important role in formation of protoplasm. Prepared by: Sidra Javed

35. Importance of Proteins Nucleoproteins are complex proteins and act as the carrier of heredity materials from one generation to another. Prepared by: Sidra Javed

36. Importance of Proteins Enzymes are the biological catalyst and they are also proteins Prepared by: Sidra Javed

37. Importance of Proteins Hemoglobin is a protein. It act as oxygen carrier. Prepared by: Sidra Javed

38. Importance of Proteins Tanning of hides is actually precipitation of proteins by tannic acid. Prepared by: Sidra Javed

39. Importance of Proteins Gelatin is obtained by heating bones, skins and tendons in water. It is used in bakery goods. Prepared by: Sidra Javed

40. Importance of Proteins Casein is another protein used in manufacture of buttons and buckles. Proteins obtained from soya bean are used for manufacture of plastics. Prepared by: Sidra Javed

41. The End Prepared by, Sidra Javed