The main organic compounds of organisms

We can find four major organic compounds  in organisms. That major organic compounds have basic chemical nature and functions. We will study them one by one.

The major organic compounds that found in organisms are,

                    •    Carbohydrates

                    •    Lipids

                    •    Proteins

                    •    Nucleic acids

 These  major organic compounds considered as major biological molecules.

  Carbohydrates

                    •   Most abundant organic matter on earth

                    •   The substances that we know as sugars and flour in day-to-day life are examples

                    •   Major elemental composition is C,H,O

                    •   General formula C_x(H₂O)_y - Hydrates of carbon contains the same proportions of

                         H:O (2:1)   found in water

                    •   Monosaccharides, disaccharides and polysaccharides are the three main classes

                         of  carbohydrates                                    

             Monosaccharides

                      •   Name monosaccharides  according to the number of C atoms as; Triose

                          (3C ) e.g. Glyceraldehyde, Tetrose (4C)  e.g. Erythrose - rare in nature,

                          Pentose (5C)  e.g.Ribose,  Ribulose, Hexose(6C) e.g. glucose, fructose, galactose.

                      •   All Monosaccharides are reducing sugars  

                      

             Disaccharides

                      •  Maltose, Lactose are reducing sugars, Sucrose is not a reducing sugar.

             Polysaccharides

                       •     Polysaccharides structured as, 1-4 glycosidic bonds and 1-6

                             glycosidic bonds. Straight chains and branched chain structure. Basic

                             structure and functions of starch, glycogen and cellulose.  Amylase

                             activity on starch. Inulin as an example of  another polysaccharide and

                             hemicellulose, pectin and chitin as important polysaccharide derivatives  

                               

    

Lipids

                         

                          •   Heterogeneous group of compounds  which are insoluble in water.

                          •   Major elemental composition is C,H,O sometimes P and/or N. Less oxygen

                                         than carbohydrates

                          •   The structure of  fatty acids  - saturated and unsaturated with examples.

                          •   Distinguish oils and fats. Triglyceride structure of oils and fats.

                          •   Give examples of other trypes of fats e.g., waxes, phospholipids, steroids

                                      And  terpenes.

                          •   Explain major functions of lipids.

                          •   Laboratory tests to identify fats and oils.

 Proteins

                          •   State proteins are  linear polymers of amino acids with high molecular

                                          weights. They contain C,H,O, N and sometimes S.

                         

                          •   State amino acids as monomer units of proteins. Although  there are

                              Several amino acids in the body only around 20 different amino acids are

                              involved in making proteins. Explain what are peptide bonds , how they are         

                              formed and Polypeptide structure.

                          •   Complex structure of proteins can be described in 4 stages.

                          •   Primary - Sequence of amino acids.

                          •   Secondary - helical or pleated sheet structure

                          •   Tertiary - bending, folding of polypeptide chains produce globular shape.

                              Different types of bonds stabilizing tertiary structure.

                          •   Quartenery- aggregation of 2 or more polypeptides to form a complex

                               structure

                          

 Nucleic acids

                          

                          •    Linear polymers of high molecular weight, contains C, H, O, N and P.

                          •    Two types - DNA and RNA.

                          •    Nucleotides as building units. Constituents of nucleotides.

                          •    Types of  N-bases. Purines and pyrimidines. Difference of  sugars and

                                          Bases of nucleotides  of  DNA and RNA

                          •    Polynucleotide structure. Explain fully the double helical structure of DNA.

                          •    Self replication of DNA

                          •    Denaturation of DNA. Renaturation of DNA.

                          •    Differences between RNA and DNA. Three different types of RNA (mRNA,

                             t-RNA and r-RNA).

                          •    Functions of DNA and RNA

                          •    Nucleotides other than those found in nucleic acids and their functions.