Question

What are the molecules (monomers) that build polysaccharides, proteins and lipids?

Answer 1

The polysaccharides are complex carbohydrates, proteins are made of polypeptide chains and lipids are made up of fats. All these biomolecules are formed by a large number of monomer chains depending upon their properties and functions.

Complete answer:
The polysaccharides are also known as complex carbohydrates which are formed by the polymerization of monosaccharide monomers and joined by the glycosidic bond. When the reaction takes place the water gets released. One type of monomer forms the homopolysaccharides whereas more than one type of monomer forms the heteropolysaccharides.
The proteins are made up of monomers of amino acids and they may be heteropolymer or homopolymer. The formation of protein from amino acid takes place by polypeptide bond. The protein may consist of one or more polypeptides. The single peptides are monomeric proteins whereas the two or more peptides are oligomeric proteins. The peptide bond in amino acids formed between the amino acids of one group to the carboxylic acid of another group.
The lipids are fatty acids that form by the reaction of alcohol therefore it is also known as fatty acid esters. Lipids do not polymeric to form the macromolecules and the basic monomer of lipid is a fatty acid that consists of a hydrocarbon chain with a carboxylic acid at the end. Depending on the presence or absence of double bonds the lipids are classified into saturated and unsaturated fatty acids.

Note:
The carbohydrates are organic molecules that are mainly divided into simple carbohydrates and complex carbohydrates. The simple carbohydrates consist of monosaccharides and oligosaccharides whereas the complex carbohydrates consist of polysaccharides only.