Cell Communication

This is a flashcard set for important terms in our unit on cell communication.

direct contact

cell communication via direct contact; examples of this type of cell communication include plasmodesmata, gap junctions and immune cell activity

autocrine signaling

the target cell is also the secreting cell

local regulators

A chemical messenger that influences cells nearby

gap junctions

provide cytoplasmic channels between adjacent animal cells, holes in cell membranes

plasmodesmata

An open channel in the cell wall of plants through which strands of cytosol connect adjacent cells

reception

A target cell's ability to detect a signal molecule coming from outside the cell; stage 1 in cell signalling .

response

The cell's reaction to a chemical messenger.

ligand

A molecular messenger that binds to specific receptors on, or within, the cell. It is not chemically altered.

receptors

Molecules (often proteins) that detect specific ligands in their internal or external environment.

paracrine signalling

type of cell communication in which chemical messengers are detected by nearby cells

endocrine signalling

long distance signaling that uses hormones as ligands that travel through the blood

hormones

Chemical messengers manufactured endocrine glands & travel through the bloodstream to distant target cells

G-protein coupled receptors

A special class of membrane receptors with an associated GTP binding protein; this receptor involves dissociation and GTP hydrolysis

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

ligand-gated ion channel

Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape.

transduction

The transfer of the signal from the cell membrane resulting in a change in cell activity; stage 2 in cell signalling.

phosphorylation cascade

A series of enzyme-catalyzed phosphorylation reactions commonly used in signal transduction pathways to amplify and convey a signal inward from the plasma membrane.

secondary messenger

A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein.

Cofactors

Organic molecules (not proteins) that assist in the normal functioning of enzymes (Zinc)

feedback inhibition

A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.

positive feedback loop

Causes a system to change further in the same direction.

negative feedback loop

A feedback loop that causes a system to change in the opposite direction from which it is moving

Homeostasis

process by which organisms maintain a relatively stable internal environment

Kinases

Enzymes that catalyze the transfer of phosphate groups from ATP to acceptor molecules.

secondary messengers

Intermediate chemicals that help transduce a chemical signal