Chapter 9: Cell Signaling

These flashcards cover key concepts in cell signaling including types of signaling, receptors, and cellular responses.

Intercellular signaling

Signaling that occurs between different cells.

Intracellular signaling

Signaling that occurs within the same cell.

Ligand

A signaling molecule that binds to a receptor to trigger a response.

Receptor

A protein that binds to a ligand to initiate a cellular response.

Paracrine signaling

Type of signaling where signals act on nearby cells.

Endocrine signaling

Type of signaling where signals are transported through the bloodstream to distant cells.

Autocrine signaling

Type of signaling where a cell signals itself.

Direct signaling

Type of signaling that occurs through gap junctions.

Signal transduction

The process of passing a signal through the cell after ligand binding.

Signaling cascade

A chain reaction of proteins activating other proteins to amplify a signal.

Phosphorylation

The process of adding a phosphate group (PO4) to a protein to change its activity.

Kinase

An enzyme that adds phosphates to proteins.

Phosphatase

An enzyme that removes phosphates from proteins.

Second messengers

Small molecules that amplify signals inside the cell, such as cAMP or Ca2+.

cAMP

A second messenger that activates A-kinase to phosphorylate other proteins.

DAG

A second messenger that activates Protein Kinase C (PKC).

IP3

A second messenger that releases calcium ions (Ca2+) from the endoplasmic reticulum.

Apoptosis

Programmed cell death that keeps organisms healthy by removing damaged or dangerous cells.

Quorum sensing

A process where bacteria communicate using autoinducers when population density is high.

Cell growth or death

Responses of the cell to signaling that can lead to either growth or programmed death.