Question #65b20

1 Answer
Dec 7, 2017

Phospho = phoshate group i.e#PO_4^(3-)#
Diester = two ester bonds i.e #2##(C-O-C)#

Explanation:

In biology, it is defined as a covalent bond present b/w two nucleotides. Thus it held the polynucleotide chains of #RNA#and #DNA# in their place.

Structure of nucleotide:
Nucleotide contain three components:

  • Phosphate group
  • Five carbon sugar: ribose #to# #RNA# and deoxyribose#to# #DNA#
  • Nitrogenous bases( purines and pyrimidines)

Nitrogen base is attached to carbon number #1# of a pentose sugar. Phosphate group is attached to carbon number #5# of the sugar. A free hydroxyl group is attached to the #3'# carbon atom.
http://www.biosyn.com/tew/numbering-convention-for-nucleotides.aspx

Formation of phosphodiesterase bond:
The #5'# phosphate and #3# hydroxyl group react chemically with each other. A covalent bond is formed between the two nucleotides releasing water molecule(dehydration reaction).

As the phosphate group link to the two sugars by two ester bonds. Thus the linkage between the two nucleotides is called phosphodiester linkage/bond.
enter image source here
https://teaching.ncl.ac.uk/bms/wiki/index.php/Phosphodiester_bond

Hope it helps...