Cell Communication 5.6 Vocab Words

Question 1

channel protein

Answer 1

A type of transport protein that functions by having a hydrophilic channel that certain molecules or atomic ions use as a tunnel through a membrane.

Question 2

ion channel

Answer 2

A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient.

Question 3

gated channel

Answer 3

A transmembrane protein channel that opens or closes in response to a particular stimulus.

Question 4

membrane potential

Answer 4

The difference in electrical charge (voltage) across a cell’s plasma membrane due to the differential distribution of ions. Affects the activity of excitable cells and the transmembrane movement of all charged substances.

Question 5

local regulator

Answer 5

A secreted molecule that influences cells near where it is secreted.

Question 6

growth factor

Answer 6

A class of local regulators that stimulate nearby target cells to grow and divide.

Question 7

paracrine signaling

Answer 7

A type of local signaling in animals in which a secreting cell acts on nearby cells by discharging a local regulator such as a growth factor.

Question 8

synaptic signaling

Answer 8

A type of local signaling in animals in which an electrical signal stimulates release of a neurotransmitter molecule into a synapse, stimulating the target cell on the other side of the synapse.

Question 9

hormone

Answer 9

In multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the body, changing the target cells’ functioning. Important in long-distance signaling.

Question 10

endocrine signaling

Answer 10

A type of long-distance signaling in animals that utilizes hormones.

Question 11

reception

Answer 11

The binding of a signaling molecule to a receptor protein, activating the receptor by causing it to change shape.

Question 12

transduction

Answer 12

The conversion of a signal from outside the cell to a form that can bring about a specific cellular response.

Question 13

signal transduction pathway

Answer 13

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

Question 14

response

Answer 14

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

Question 15

ligand

Answer 15

A molecule that binds specifically to another molecule, usually a larger one.

Question 16

G protein-coupled receptor

Answer 16

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

Question 17

G protein

Answer 17

A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell.

Question 18

ligand-gated ion channel

Answer 18

A transmembrane protein containing a pore that opens or closes as it changes shape in response to a signaling molecule (ligand), allowing or blocking the flow of specific ions; also called an ionotropic receptor.

Question 19

transcription factor

Answer 19

A protein that controls which genes are turned on.

Question 20

protein kinase

Answer 20

An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein.

Question 21

protein phosphatase

Answer 21

An enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase.

Question 22

second messenger

Answer 22

A small, nonprotein, water-soluble molecule or ion, such as a calcium ion (Ca2+) or cyclic AMP, that relays a signal to a cell’s interior in response to a signaling molecule bound by a signal receptor protein.

Question 23

cyclic AMP

Answer 23

Cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (secondary messenger) in eukaryotic cells. It is also a regulator of some bacterial operons.

Question 24

phosphorylation cascade

Answer 24

A series of chemical reactions during cell signaling mediated by enzymes (kinases), in which each kinase in turn phosphorylates and activates another, ultimately leading to phosphorylation of many proteins.

Question 25

Autocrine Signaling

Answer 25

a type of cell signaling where a cell releases a ligand that binds to a receptor on its own cell membrane. SELF SIGNALING

Question 26

Juxtacrine Signaling

Answer 26

a type of cell signaling where two cell are directly connected by proteins on the cell membranes of each cell. When these protein interact, a signal is conveyed in at least one of the cells. This is also the type of signaling that occurs through gap junctions or plasmodesmata. SIGNALING WHEN DIRECTLY CONNECTED