Question

What is the difference between a nucleotide and a nucleoside? Give two examples of each with their structure.

Answer 1

Structure

Nucleotides are compounds composed of nucleosides esterified with a phosphate group.
Nucleosides are compounds composed of nitrogen bases attached to pentose sugar molecules.



Presence of phosphate group

Phosphate group is present in a nucleotide (Nucleotide = Nitrogenous base + Sugar + Phosphate).
Phosphate group is absent in a nucleoside (Nucleotide = Nitrogenous base + Sugar).

Chemical nature

Nucleotides are acidic in nature due to the presence of the phosphate group.
Nucleosides are not acidic due to the absence of phosphate groups.

Examples

Examples of nucleotides include ATP, GTP, CTP etc. Examples of nucleosides include adenosine, guanosine, cytidine etc.

Summary

Criteria	Nucleotide	Nucleoside
Structure	Nucleosides esterified with a phosphate group	Nitrogen bases attached to pentose sugar
Presence of phosphate group	Phosphate group is present in a nucleotide (Nucleotide = Nitrogenous base + Sugar + Phosphate).	Phosphate group is absent in a nucleoside (Nucleotide = Nitrogenous base + Sugar).
Chemical structure	Acidic in nature due to the presence of the phosphate group	Not acidic due to the absence of phosphate groups
Examples	Examples: ATP, GTP, CTP etc.	Examples of nucleosides: Adenosine, guanosine, cytidine etc.