Tuesday, 12 August 2014

NUCLEIC ACIDS:: PART 4

Nucleotides

-          These have several functions in the cell.

-          Form DNA and RNA.

-          Carriers of chemical energy: -

o   Nucleotides with one, two or three phosphate groups are called monophosphate, diphosphate or triphosphate.
o   NTPs (nucleotide triphosphate) are sources of energy in any biochemical reaction.
                                  
o   ATP is widely used but other NTPs are used in specific reactions.
o   Hydrolysis of NTPs releases energy.

-          Enzyme cofactors: -

o   Many enzyme cofactors and coenzymes contain adenosine as part of their structure.
o   Removal of adenosine from the cofactors decreases their activity.
                                
o   Example: - acetyl Co-A.

-          Chemical messenger: -

o   Hormones and chemical signalling agents are called messengers.

o   These messengers induce secondary messengers inside the cells which are generally nucleotides.

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