Biological Molecules Notes

Biological Molecules

• All matter consists of atoms.

• Atoms form molecules.

• Molecules and elements form cells and cell structures in organisms.

• The cell is the smallest living unit of life.

Types of Molecules

1. Inorganic (water and minerals)

2. Organic (proteins, fats, carbohydrates, and vitamins)

Functions of Water

1. Powerful solvent.

2. Medium for chemical reactions.

3. Transports wastes and nutrients.

4. Substrate in photosynthesis.

5. Cooling of surfaces in animals through sweat.

6. Provides support and structure in plants.

7. Reagent during hydrolysis.

Inorganic Compounds

• Do not contain carbon (C), exception is $CO_2$.

• Not of biological origin.

• Includes water and minerals.

• Example: Table salt (NaCl).

Organic Compounds

• Contain carbon (C), oxygen (O), and hydrogen (H).

• Always of biological origin.

• May contain nitrogen (N), phosphorous (P), and sulphur (S).

• Includes carbohydrates, proteins, fats, vitamins, and nucleic acids.

• Example: Sunflower oil.

Inorganic Molecules

1. Water ($H_2O$)

• Necessary for life; the human body is about 70% water.

2. Minerals

• Natural inorganic elements for chemical reactions.

• Categories:

  1. Macro-minerals (large amounts).

  2. Micro-minerals (small amounts).

  • Different minerals are required by plants and animals.