Which one is not a protein?

The correct answer is a lymphocyte.
Key Points

• Immunity is the protection of oneself from the invading pathogen.
• Our body has innate and specific immunity.
• Lymphocytes are the type of leucocytes that helps in killing the pathogen.
• It is B -lymphocyte and a T -lymphocyte.
• It produces the antibody, that binds with the antigen.
• B-cell or lymphocyte develops in the bone marrow and is present in the blood plasma.
• The T-lymphocytes form in bone marrow but mature in the thymus,  thus the term T-lymphocyte.
• A lymphocyte is a cell formed by haematopoiesis in the bone marrow.
• A lymphocyte is not a protein.

Additional Information

• Protein forms by the polymerisation of amino acids.
• It consists of primary, secondary, and tertiary or quaternary structures.

Collagen:

• It is a protein that forms an internetwork connection.
• It consists of alpha-helical structures.
• It is present in the extracellular matrix and thus supports the tissues.

Elastin:

• It is a protein present in the extracellular matrix.
• It stretches up to 5 times its length.
• It provides elasticity to the body.

Silk:

• It is a protein secreted by silkworms.
• It consists of fibroin and sericin proteins.
• It is used in the making of clothes and bedsheets.