The document categorizes various classes of proteins based on their functions. It includes examples such as enzymatic proteins like urease, structural proteins like collagen, transport proteins like hemoglobin, and defensive proteins like antibodies. Additionally, it highlights proteins involved in nutrient storage and regulatory functions.

3. Class of protein Functions Example
1. Enzymatic protein Biological catalyst Urease, Amylase, Catalase, Cytochrome
C, Alcohol hydrogenase
2. Structural protein Strengthening and protecting biological
structure
Collagen, Elastin, Keratin, Fibroin
3.Transport and carrier protein Transport of ion and molecules in a body Myoglobin, hemoglobin, Ceruloplasmin,
Lipoproteins
4. Nutrient and storage protein Provide nutrition to growing embryo and
store ions
Ferritin, Casein, ovalbumin
5. Contractile or motile protein Function in contractile system Actin, Myosin,Tubulin
6. Defence protein Defend against other organisms Antibodies, Fibrinogen,Thrombin
7.Toxin protein Hydrolyse or degrade enzymes Snake venom, Ricin
8. Regulatory protein Regulate cellular or metabolic activities Insulin, G protein, Growth hormone