Proteins

Step 1: Understand the Proteins and Their Functions

• Collagen: A structural protein that forms part of the extracellular matrix and connective tissues. It is involved in providing intercellular ground substance.
• Trypsin: An enzyme that aids in the breakdown of proteins in the digestive system.
• Insulin: A hormone that regulates glucose levels in the blood.
• Antibody: Proteins that fight infectious agents by recognizing and neutralizing pathogens like bacteria and viruses.

Step 2: Match the Proteins with Their Functions

• Collagen → Intercellular ground substance (s)
• Trypsin → Enzyme (r)
• Insulin → Hormone (q)
• Antibody → Fights infectious agents (p)

The correct answer is (D) : 1-s, 2-r, 3-q, 4-p.