Biomolecules are the essential organic molecules involved in the maintenance and metabolic processes of living organisms.
The following are the four types of biological molecules:
- Nucleic acid
Carbohydrates are chemically defined as polyhydroxy aldehydes or ketones or compounds which produce them on hydrolysis. Depending on the number of constituting sugar units obtained upon hydrolysis, they are classified as monosaccharides (1 unit), oligosaccharides (2-10 units) and polysaccharides (more than 10 units).
- Polysaccharides are a long chain of sugar-containing different monosaccharides as building block.
Proteins are polypeptide chains made up of amino acids. There are 20 types of amino acids joined together by a peptide bond between the amino and carboxylic group. The structure of proteins is classified as primary, secondary, tertiary and quaternary in some cases. These structures are based on the level of complexity of the folding of a polypeptide chain.
- Transport of nutrient across the membrane.
- Fight infectious organisms.
- Produce enzyme and proteins.
Lipids are organic substances that are insoluble in water, soluble in organic solvents, related to fatty acids, and utilized by the living cell.
- They include fats, waxes, oils, hormones, and certain cellular components and function as energy-storage molecules and chemical messengers.
Nucleic acids are polynucleotides. A nucleic acid has three chemically distinct components- heterocyclic compound ( nitrogenous base), polysaccharides ( ribose/ deoxyribose sugar), phosphate, or phosphoric acid.
- The sugar found in nucleic acid is either ribose or deoxyribose. A nucleic acid containing deoxyribose sugar is called DNA (Deoxyribonucleic Acid), and those containing ribose sugars are called RNA (Ribonucleic acid).
- The nitrogen base attached to the pentose sugar makes the nucleotide distinct. There are 4 major nitrogenous bases found in DNA: adenine, guanine, cytosine, and thymine. In RNA, thymine is replaced by uracil.