Chapter 09: Biomolecules

What are Biomolecules?

Definition: Chemicals or molecules present in living organisms.
Types:
- Inorganic: Includes minerals, gases, and water.
- Organic: Includes carbohydrates, fats, proteins, nucleic acids, vitamins.

Formation: Except lipids, they are formed by polymerization of monomers.
Proteins:
- Polymers of amino acids.
- Linked by peptide bonds formed between COOH group of one amino acid and NH3 group of the next with the removal of H2O.
Nucleic Acids:
- Phosphate molecules link 3 C of sugar of one nucleoside to the 5 C of sugar of next nucleosides.
- Forms 3-5 phosphodiester bond releasing two water molecules.
Polysaccharides:
- Monosaccharides linked by glycosidic bonds formed by dehydration between two carbon atoms of two adjacent monosaccharides.

Structure: Long chains of sugars with different monosaccharides as building blocks.
Starch:
- Present in plants as an energy storehouse.
- Forms helical secondary structure.
- Can hold I2 molecules in its helical structure.
Cellulose:
- Composed of glucose molecules joined by 1-4 linkages.
- Most abundant organic molecule on Earth.
Glycogen:
- Known as animal starch.
- Reserve food material for animals, bacteria, and fungi.
- Glucose molecules arranged in highly branched bush-like chain with two types of linkages: 1-4 in straight chain and 1-6 in branching.

Structure: Polypeptide chains made up of 20 types of amino acids.
Bonds: Joined together by peptide bonds between amino and carboxylic groups.
Types of Amino Acids:
1. Essential Amino Acids: Obtained from food by living organisms.
2. Non-essential Amino Acids: Can be synthesized by the body from raw materials.
Functions of Proteins:
1. Transport nutrients across membranes.
2. Fight against infectious organisms.
3. Produce enzymes and proteins.

End of Chapter 09: Biomolecules