Front

What is signal transduction?

Back

The process by which a cell responds to external signals through a series of molecular events, leading to a cellular response.

Front

What is a ligand?

Back

A signaling molecule that binds to a specific receptor to initiate a signal transduction pathway.

Front

What is a receptor?

Back

A protein on the cell surface or inside the cell that binds to a ligand and initiates a response.

Front

What is a secondary messenger?

Back

A molecule that relays signals received at receptors on the cell surface to target molecules inside the cell.

Front

Give an example of a secondary messenger.

Back

Calcium ions (Ca2+) are a common secondary messenger involved in various signaling pathways.

Front

Where is calcium stored in muscle cells?

Back

Calcium is stored in the smooth endoplasmic reticulum (smooth ER) of muscle cells.

Front

How is calcium released from the smooth ER?

Back

Calcium is released from the smooth ER through gated ion channels.

Front

What role do gated ion channels play in signal transduction?

Back

Gated ion channels allow specific ions to flow in or out of the cell in response to a signal, contributing to cellular responses.

Front

What is the difference between a primary messenger and a secondary messenger?

Back

A primary messenger (like a hormone) is the initial signal that binds to a receptor, while a secondary messenger (like cAMP or Ca2+) amplifies the signal inside the cell.

Front

What is the function of ATP in signal transduction?

Back

ATP serves as an energy source for various cellular processes, including the activation of proteins in signal transduction pathways.