CAMPBELL BIOLOGY CHAPTER 11 FLASHCARDS 11TH EDITION

AP BIO UNIT 4

Adenylyl cyclase

An enzyme embedded in the plasma membrane that converts ATP to cAMP in response to an extracellular signal.

Amplification

The strengthening of a stimulus energy during the transduction pathway.

Apoptosis

Programmed cell death.

Cyclic AMP (cAMP)

A ring-shaped molecule made from ATP that is a common intracellular signaling molecule – often a second messenger during signaling pathways.

Hormones

A secreted chemical formed in specialized cells; travels in body fluids and acts on specific target cells to change how they function (leading to a response).

G-Protein-Coupled Receptor

A signal receptor protein in the plasma membrane that responds to the binding of a signaling molecule by activating a specific protein.

Ligand

A molecule that specifically binds to another molecule (often within the membrane) to generally cause receptor proteins to change shape.

Ligand gated ion channel

A “door” mechanism controlled by ligands (specific chemicals) to allow or block specific ions through.

Paracrine

Signaling molecules secreted by signal cells that travel only short distances, influencing cells in the vicinity.

Phosphorylation cascade

A series of reactions mediated by kinases that phosphorylate other kinases, leading to large-scale phosphorylation of proteins that ultimately leads to cellular responses.

Plasmodesmata

Open channels through cell walls that connect the cytoplasm of adjacent plant cells to allow passage between cells.

Protein kinase

An enzyme that catalyzes the transfer of phosphate groups from ATP to another protein.

Protein phosphatases

Enzymes that remove phosphates from proteins.

Reception

The first step of the signaling pathway in which a signaling molecule is detected by the molecule/protein on or at the cell.

Receptor Tyrosine Kinases

Membrane receptors that attach phosphates to tyrosines.

Response

The change in a specific cellular activity brought about by a transduced signal from outside the cell.

Second messengers

A small, non-protein, water-soluble molecule or ion that relays a signal to the cell’s interior in response to a signaling molecule.

Signal Transduction Pathway

A series of steps linking a mechanical, chemical, or electrical stimulus to a cellular response.