Question

Receptors for protein hormones are found
(a) inside nucleus (b) inside cytoplasm
(c) on surface of ER (d) on cell surface

Answer 1

Answer is option "d"

Explanation:

• Protein hormones are peptide hormones which are derived from amino acids. These are insoluble in lipids and hence can't enter the target cell (cell membrane is a lipid bilayer).
• These act as primary messengers at the surface of target cell by binding to cell surface receptors and this results in the formation of a hormone-receptor complex.
• Hence, the correct answer is option d " On cell surface".

Answer 2

Receptors for protein hormones are found (d) on cell surface.

• Protein hormones are the hormones derived from amino acids in the peptides. These are insoluble in lipids, and therefore can not reach the target cell.
• These serve as primary messengers at the target cell surface by binding to cell surface receptors, resulting in the development of a complex of hormone-receptors.
• Thus, the receptiors for protein are found on the plasma membrane of the cell'