I have read in books that Proteins and Peptides are fundamental components of cells which carryout important biological functions.Can any one explain me the structural difference between Proteins and Peptides?
In terms of structure: both are composed of amino acids.
A peptide is when at least two amino acid are linked together. A protein is composed of multiple amino acids and have a secondary, tertiary and even quaternary structure.
In terms of function: larger molecules have more complex functions.
Peptides can act as a intracellular or extracellular ligands which will activate a signal.
Proteins have a large array of functions (enzymatic, structural, receptors etc)
This article explains in more details the differences in proteins structure and functions:https://en.wikibooks.org/wiki/Structural_Biochemistry/Proteins