Question

what occurs when hormones reach their target cells?
multiple choice
the hormone undergoes a conformational change to enter the cell
the hormone becomes an integral part of the cell membrane
the hormone causes the release of a neurotransmitter
the hormone binds to an appropriate receptor on (in) the target cell

Explanation:

Hormones act on target cells by binding to specific receptors. This binding is highly specific, similar to a key - lock mechanism.

• Hormones do not generally undergo a conformational change to enter the cell (except for some lipid - soluble hormones which can pass through the cell membrane, but the question is about the general mechanism when they reach target cells).
• Hormones are not an integral part of the cell membrane.
• Hormones are not directly responsible for the release of neurotransmitters (that is a function related to neurons in most cases).

Answer:

The hormone binds to an appropriate receptor on (in) the target cell