classification of protein 1st year biology STBB

Описание: Classification of Proteins – Class XI Biology (STBB)

Proteins are complex organic compounds made up of amino acids. They are essential for the structure and function of all living cells. Based on their structure, composition, and function, proteins are classified into the following main categories:

1. Based on Structure:
a. Fibrous Proteins

Long, thread-like, and insoluble in water.

Provide structural support to cells and tissues.

Examples: Collagen, Keratin, Myosin

b. Globular Proteins

Spherical or globe-shaped and soluble in water.

Involved in metabolic functions.

Examples: Hemoglobin, Enzymes, Antibodies

2. Based on Composition:
a. Simple Proteins

Made only of amino acids.

only amino acids on hydrolysis.

Examples: Albumin, Globulin

b. Conjugated Proteins

Consist of amino acids and a non-protein part (prosthetic group).

Non-protein parts can be metal ions, lipids, carbohydrates, etc.

Examples:

Glycoproteins (protein + carbohydrate)

Lipoproteins (protein + lipid)

Metalloproteins (protein + metal ion)

Nucleoproteins (protein + nucleic acid)

3. Based on Function:

Proteins perform a wide range of functions in living organisms:

Type Function Example
Structural Provide support and shape Collagen, Keratin
Enzymatic Catalyze biochemical reactions Amylase, Protease
Transport Carry substances within the body Hemoglobin, Albumin
Hormonal Regulate physiological processes Insulin, Growth hormone
Defensive Protect against disease Antibodies
Contractile Help in movement Actin, Myosin
Storage Store amino acids or other substances Casein (milk protein