Structures of nucleic acid ,carbohydrates and general formula for amino acids are most important structures.

Introduction:
Biomolecules are essential for the functioning of living organisms. They are organic molecules that are involved in various biological processes. There are four major classes of biomolecules: carbohydrates, lipids, proteins, and nucleic acids. Each class has its own unique structures that contribute to their specific functions.

Carbohydrates:
- Monosaccharides: These are the basic building blocks of carbohydrates. They are simple sugars, such as glucose and fructose.
- Disaccharides: Formed by the joining of two monosaccharides through a glycosidic bond. Examples include sucrose and lactose.
- Polysaccharides: These are complex carbohydrates made up of many monosaccharide units. They serve as energy storage molecules (e.g., starch in plants and glycogen in animals) and structural components (e.g., cellulose in plant cell walls and chitin in the exoskeleton of arthropods).

Lipids:
- Triglycerides: Composed of glycerol and three fatty acids. They are the primary storage form of energy in the body and provide insulation and protection.
- Phospholipids: Consist of a glycerol backbone, two fatty acids, and a phosphate group. They make up the cell membrane, forming a lipid bilayer.
- Steroids: Have a characteristic four-ring structure. Examples include cholesterol, which is a component of cell membranes, and hormones like estrogen and testosterone.

Proteins:
- Amino Acids: These are the building blocks of proteins. They contain an amino group, a carboxyl group, and a side chain.
- Primary Structure: Refers to the linear sequence of amino acids in a protein.
- Secondary Structure: Results from hydrogen bonding between amino acids, forming alpha-helices or beta-sheets.
- Tertiary Structure: The overall three-dimensional folding of a protein, determined by interactions between amino acid side chains.
- Quaternary Structure: Exists in proteins with multiple polypeptide chains, where the individual subunits come together to form a functional protein.

Nucleic Acids:
- Nucleotides: Consist of a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, guanine, cytosine, thymine, or uracil).
- DNA: Double-stranded helical structure, with complementary base pairing between adenine-thymine and guanine-cytosine.
- RNA: Single-stranded structure, involved in various cellular processes like protein synthesis.

Conclusion:
Understanding the structures of biomolecules is crucial for comprehending their functions in living organisms. The specific arrangements of atoms and functional groups within carbohydrates, lipids, proteins, and nucleic acids determine their unique properties and enable them to carry out a wide range of biological roles.