biological molecules

Biological molecules are essential components of living organisms and can be categorized into four main types:

1. Carbohydrates

   • Composed of carbon, hydrogen, and oxygen, with a general formula of (CH₂O)ⁿ.

   • Function as energy sources and structural components.

   • Types:

     • Monosaccharides: Simple sugars (e.g., glucose, fructose).

     • Disaccharides: Two monosaccharides linked (e.g., sucrose, lactose).

     • Polysaccharides: Long chains of monosaccharides (e.g., starch, glycogen, cellulose).

2. Proteins

   • Made up of amino acids linked by peptide bonds.

   • Serve various functions including catalyzing reactions (enzymes), transporting molecules, and providing structural support.

   • The structure of proteins has four levels:

     • Primary: Sequence of amino acids.

     • Secondary: Alpha-helices and beta-pleated sheets formed by hydrogen bonds.

     • Tertiary: Three-dimensional folding of a protein.

     • Quaternary: Association of multiple polypeptide chains.

3. Lipids

   • Hydrophobic molecules mainly composed of carbon and hydrogen.

   • Function in energy storage, signaling, and serving as structural components of cell membranes.

   • Types:

     • Fatty acids: Saturated (no double bonds) or unsaturated (one or more double bonds).

     • Triglycerides: Three fatty acids linked to glycerol.

     • Phospholipids: Glycerol, two fatty acids, and a phosphate group; important for cell membranes.

4. Nucleic Acids

   • Made up of nucleotides, which contain a phosphate group, a sugar, and a nitrogenous base.

   • Function in storing and transmitting genetic information.

   • Types:

     • DNA (Deoxyribonucleic acid): Stores genetic information; double-stranded helix structure.

     • RNA (Ribonucleic acid): Involved in protein synthesis; single-stranded; types include mRNA, tRNA, and rRNA.