AP Bio Insta-Review Topic 4.2: Intro to Signal Transduction

Front

What is a signaling molecule?

Back

A signaling molecule, also known as a ligand, is a chemical substance that transmits signals to cells, binding to specific receptors to elicit a response.

Front

Where does a ligand bind?

Back

A ligand binds to a receptor on the surface of a target cell.

Front

Do all cells in an organism respond to a ligand?

Back

No, not all cells respond to a ligand because they may lack the specific receptors needed to bind the ligand.

Front

What is signal transduction?

Back

Signal transduction is the process by which a cell responds to external signals, involving the conversion of a signal from one form to another.

Front

What role do secondary messengers play in signal transduction?

Back

Secondary messengers amplify the signal within the cell after the receptor has been activated by a ligand.

Front

What is an example of a secondary messenger?

Back

Calcium ions (Ca²⁺) are a common example of a secondary messenger.

Front

What is a receptor?

Back

A receptor is a protein molecule on the surface of a cell that binds to specific signaling molecules (ligands) and initiates a cellular response.

Front

What is the difference between a ligand and a substrate?

Back

A ligand is a signaling molecule that binds to receptors, while a substrate is a molecule upon which an enzyme acts.

Front

What is a phosphorylation cascade?

Back

A phosphorylation cascade is a series of chemical reactions in a cell where one enzyme phosphorylates another, leading to a chain reaction that amplifies the signal.

Front

What are ligands involved in?

Back

Ligands are involved in the initial step of signal transduction by binding to receptors.