Biomolecules Test - 6

Complete hydrolysis of DNA yields a pentose sugar, phosphoric acid and nitrogen containing heterocyclic compounds (called bases). In DNA molecules, the sugar moiety is β-D-2-deoxyribose.

B group vitamins and vitamin C are soluble in water so they are grouped together as water soluble vitamins. These must be supplied regularly in diet because they are readily excreted in urine and cannot be stored (except vitamin B₁₂) in our body.

Certain organic compounds are required in small amounts in our diet but their deficiency causes specific diseases. These compounds are called vitamins. Most of the vitamins cannot be synthesised in our body but plants can synthesise almost all of them, so they are considered as essential food factors. However, the bacteria of the gut can produce some of the vitamins required by us. All the vitamins are generally available in our diet.

A unit formed by the attachment of a base to 1′ position of sugar is known as nucleoside. Adenosine is nucleoside composed of adenine attached a ribose sugar molecule.

When nucleoside is linked to phosphoric acid at 5′-position of sugar moiety, we get a nucleotide. ATP (Adenosine triphosphate) is nucleotide of adenosine with 3 phosphoric acid molecules.

Various RNA (ribonucleic acid) molecules in the cell guide synthesise the proteins.

Vitamin B₂ is also called Riboflavin.

Deficiency of Vitamin B₁₂ results in Pernicious anaemia (Red Blood Cells deficient in haemoglobin)

Nucleotides are together by phosphodiester linkage between 5′ and 3′ carbon atoms of the pentose sugar.