1. Carbohydrates: These are the primary energy source for most living organisms. They are composed of carbon, hydrogen, and oxygen in a ratio of approximately 1:2:1. Examples include sugars, starches, and cellulose.
* Monosaccharides: Simple sugars like glucose and fructose.
* Disaccharides: Two monosaccharides joined together, like sucrose (table sugar).
* Polysaccharides: Long chains of monosaccharides, like starch (energy storage in plants) and glycogen (energy storage in animals).
2. Lipids (Fats and Oils): Lipids are primarily hydrophobic (water-repelling) molecules, and they serve as energy storage, insulation, and structural components of cell membranes.
* Triglycerides: The most common type, formed from glycerol and three fatty acids.
* Phospholipids: Form the basis of cell membranes.
* Steroids: Include cholesterol, which is important for cell structure, and hormones like testosterone and estrogen.
3. Proteins: These are complex molecules made up of amino acids linked together in chains. Proteins have diverse functions, including:
* Enzymes: Catalyze (speed up) biochemical reactions.
* Structural components: Provide support and shape, like collagen in connective tissue.
* Hormones: Act as chemical messengers.
* Antibodies: Part of the immune system, defending against disease.
4. Nucleic Acids: These are complex molecules responsible for storing and transmitting genetic information.
* Deoxyribonucleic acid (DNA): Carries the genetic code for an organism.
* Ribonucleic acid (RNA): Plays a key role in protein synthesis and other cellular processes.
These are just four of the many types of biochemicals found in living organisms. Other important classes include:
* Vitamins: Organic compounds that are essential for specific metabolic processes.
* Minerals: Inorganic elements that are crucial for various biological functions.
* Water: Essential for many biological processes, including dissolving substances, transporting nutrients, and regulating temperature.
