CHAPTER ONE 

INTRODUCTION

Plants use carbon dioxide and water to produce glucose through the process of photosynthesis. The combination of glucose with other monosaccharide gives starch and cellulose. Energy is stored in plants in form of carbohydrate, thus carbohydrate is known as the energy giving food. The energy giving food is composed majorly of carbon, hydrogen and oxygen and has the general molecular formula Cx(H20)y. Carbohydrates can be classified naturally into simple sugar which include the monosaccharide e.g. glucose, fructose, mannose and galactose, the disaccharides (formed from the condensation of two monosaccharide with the loss of a water molecule) e.g. sucrose, maltose and lactose. Complex sugar also called polysaccharides (formed from the condensation of more than two monosaccharide) e.g. starch, glycogen and cellulose. Carbohydrate is commonly, found on fruits, sap of plants e.g. tuber plants and grain crops. And also in honey.

Glycobiology is the study of the structure, biosynthesis, chemical synthesis and biology of saccharide (sugar chains or glycans). The importance of sugar can never be over emphasized since it is an essential component of living organism and it serves as the major sources of energy. According to the research done by various fields like medical, biochemical and biotechnological field sugar plays an important role in biology.

In the broadest sense glycobiology can be defined as the study of the roles of carbohydrates in cellular life. Often they are continently bound to proteins (glycoproteins) and lipids (glycololipids to form glycoconjugates. Many glycol conjugates have structural roles. However, the carbohydrates groups of gylycoconjugates also can be involved in cellular processes including adhesion, transformation, growth, endocytosis and fertilization.

1.0 OCCURRENCE AND PRODUCTION

The occurrence of glycobiology in the living cells include the following.

1. The outer membrane of all living cells in nature is majorly composed of a dense and complex array of sugar chains (glycans).

2. Many classes of glycans and glycoconjugates is found on the bacteria and archea cell walls.

3. In eukaryotic organism most of proteins been secreted contains very large amount of covalently bond glycans.

4. Also in eukaryotes, the cells surface and secreted glycans are mostly assembled via the Endoplasmic Reticulum – Golgi pathway.

5. When the extracellular matrix of eukaryotes are viewed it is found out that it is rich in secreted glycan.

6. Eukaryotes also possess cytosolic and nuclear glycans.