Biological Molecules

Biological molecules or biomolecules are the molecules that are directly involved in the formation of living organisms. They are essential for the structure, function, and regulation of living organisms. These biological molecules are typically composed of 25 elements. Among those 25 elements 6 are more commonly found. The six common elements found in biological molecules are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), and sulfur (S). Biological molecules are of 4 types:

  1. Carbohydrates
  2. Proteins
  3. Nucleic Acids
  4. Lipids

Carbohydrates

What are the functions of carbohydrates?

  1. Carbohydrates are the main source of energy in the body. Carbohydrates are broken down into glucose when ingested as food, and most cells use this glucose for energy or store it as glycogen in the liver and muscles for future use.
  2. Glucose from carbohydrates serves as the sole energy supplier for the brain and central nervous system.
  3. Carbohydrates provide energy to the body's muscles. Glycogen is one of the heart's main sources of energy.
  4. Carbohydrates ensure that protein is not diverted from its intended vital physiological frunction and converted into energy.
  5. Complex carbohydrates such as indigestible carbohydrates and cellulose, pectin help in the formation and elimination of stool.
  6. Adequate fiber-rich complex carbohydrates in the diet regulate blood glucose levels.

Proteins

What are the functions of proteins?

  1. Food containing protein provides energy to our body and helps in physical growth and maintenance.
  2. Helps in numerous biochemical reactions inside and outside the cell.
  3. Some of the protein hormones are chemical messengers. They help in communication between body tissues and organs.
  4. Proteins play an important role in regulating and maintaining the balance of acid and alkali concentrations in the blood and other body fluids.
  5. Proteins help our body produce antibodies to fight infections from foreign microorganisms.

Nucleic Acids

DNA

What are the functions of DNA?

  1. Possesses and controls all the characteristics of the organism.
  2. Acts as a structural component of chromosomes.
  3. Acts as the molecular basis of heredity.
  4. Acts as a regulator of all physiological and biological functions.
  5. When the structure of DNA is disturbed, it repairs itself.
  6. It plays a key role in evolution by creating variation through mutation.

RNA

What are the functions of RNA?

  1. The main function of RNA is to synthesize proteins.
  2. Carrying messages from DNA to ribosomes.
  3. Carrying heredity characteristics.

Lipids

Properties of Lipids

  1. Lipids are insoluble in water.
  2. Lipids are colorless, tasteless, and odorless.
  3. Lipids are soluble in chloroform, acetone, benzene etc.
  4. Lipids have no specific melting point. Its melting point increases with increasing molecular weight.

What are the functions of lipid?

  1. Lipids combine with proteins to form lipoproteins, which are involved in energy production process.
  2. A type of lipid called phospholipids acts as a component in various membrane structures.
  3. A type of lipid plays a special role in the photosynthesis process of plants.
  4. Lipids such as fats and oils are stored in the plant body as food of various oilseeds. Lipids are ingested during germination.
  5. Waxy lipids form a layer on the outer coat of leaves to prevent excessive transpiration and it also protects the plant from various insect attacks.