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

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 are secondary messengers?

Back

Molecules that relay signals received at receptors on the cell surface to target molecules inside the cell, amplifying the signal.

Front

Give two examples of secondary messengers.

Back

Calcium ions (Ca²⁺) and cyclic adenosine monophosphate (cAMP).

Front

How do gated ion channels function in signal transduction?

Back

They open or close in response to specific signals, allowing ions to flow across the membrane and alter the cell's electrical potential.

Front

What role does calcium play in muscle contraction?

Back

Calcium ions released from the smooth ER bind to proteins that enable muscle contraction.

Front

What is the difference between a ligand and a substrate?

Back

A ligand binds to a receptor to initiate a signal, while a substrate is a molecule upon which an enzyme acts.

Front

What happens when a ligand binds to its receptor?

Back

It triggers a conformational change in the receptor, activating the signal transduction pathway.

Front

What is the significance of specificity in signal transduction?

Back

Different cells can respond differently to the same signal due to the presence of different receptors and signaling pathways.