structure of DNA 

DNA is a ribose sugar which is abbrivated as Deoxyribonocleiac Acid.
its very important to code for the genetic information from parents to offosprings.

 

The basic building block of DNA was known as nucleotide. consisting of the five car bons sugars.Ther are two types of  nitrogenous bases present in a nucleic acid,Prymidines which contain a single ring,and Purines which contain a two rings.

DNA contain two different type of Pyrimidines that is thymine and cytosine.

Two different types of purines that is Guanine and Adinine

These nucloeride is covlentely linked to one another to form a Linear strand, with alternating sugar and phosphate group joined by 3-5 phosphodiester  bond.

X-ray analysis shows diffraction analysis indicating that the distance between the nucleotide of the stack was 3.4nm.

CARBOHYDRATES

As the name represent carbon or hydrates mean hydrogen and ooxygen.

carbohyrates has ratio of hydrogen twice that of carbon.

   simplest carbohydrate that is we used in our dite is

bread potatoes and rice.

Types of carbohydrates

1)MONOSACCHARIDES

2)DISACCHARIDES

3)OLIGOSACCAHRIDES

4)PLYSACCHARIDES

MONOSACCAHRIDES

 These simple sugars can combine with each other to form more complex carbohydratesnd oxygen.

Monosaccharide classifications based on the number of carbons

Number of Carbons	Category Name	Examples
4	Tetrose	Erythrose, Threose
5	Pentose	Arabinose, Ribose, Ribulose, Xylose, Xylulose, Lyxose
6	Hexose	Allose, Altrose, Fructose, Galactose, Glucose, Gulose, Idose, Mannose, Sorbose, Talose, Tagatose
7	Heptose	Sedoheptulose, Mannoheptulose

  A chain-form monosaccharide that has a carbonyl group (C=O) on an end carbon forming an aldehyde group (-CHO) is classified as an aldose. When the carbonyl group is on an inner atom forming a ketone, it is classified as a ketose.

D-Erythrose	D-Threose

 Hexoses that has molecular formula C₆H₁₂O₆. German chemist Emil Fischer (1852-1919) identified the stereoisomers for these aldohexoses in 1894. He received the 1902 Nobel Prize for chemistry for his work.

D-Allose

D-Altrose

D-Glucose

D-Mannose

D-Gulose

D-Idose

D-Galactose

DISACCHARIDES

Disaccharides consist of two simple sugars

Sucrose, also called saccharose, is ordinary table sugar refined from sugar cane or sugar beets. It is the main ingredient in turbinado sugar, evaporated or dried cane juice, brown sugar, and confectioner's sugar. Lactose has a molecular structure consisting of galactose and glucose

Sucrose

POLYSACCAHRIDES

Many polysaccharides, unlike sugars, are insoluble in water. Dietary fiber includes polysaccharides and oligosaccharides that are resistant to digestion and absorption in the human small intestine but which are completely or partially fermented by microorganisms in the large intestine. The polysaccharides described below play important roles in nutrition, biology, or food preparation.

BASIC TYPES OF POLYSACCHARIDES ARE:

STARCH

CELLULOSE