Unit 9: Cell Communication

Question 1

Signaling Cell

Answer 1

The source of the signaling molecule

Question 2

Signalling Molecule

Answer 2

Binds to a receptor molecule on or in the responding cell

Question 3

Receptor Molecule

Answer 3

Receives the signaling molecule

Question 4

Responding Cell

Answer 4

Receives the signaling molecule on its receptor molecule

Question 5

Activated

Answer 5

A turned on receptor after the signaling molecule binds to it

Question 6

Signal Transduction

Answer 6

A receptor that transmits through the cytoplasm

Question 7

Response

Answer 7

Varies depending on the nature of the signal and the type of responding cell

Question 8

Termination

Answer 8

Allows the cell to respond to new signals

Question 9

Endocrine Signaling

Answer 9

Signalling involving molecules that travel through the bloodstream

Question 10

Paracrine Signalling

Answer 10

A signaling molecule needs to diffuse only a short distance to the nearest neighbouring cell in order to bind its receptor and deliver its message

Question 11

Autocrine Signalling

Answer 11

Signaling where the signaling cell and responding cell are the same

Question 12

Growth Factor

Answer 12

A small soluble molecule in paracrine signaling

Question 13

Juxtacrine Signalling

Answer 13

Signal that involves direct physical contact without a chemical signal that diffuses or circulates through an external medium

Question 14

Ligand

Answer 14

A term used for signaling molecule

Question 15

Ligand-Binding Site

Answer 15

A location on the receptor where the signaling molecule binds to

Question 16

G-Protein Coupled Receptor

Answer 16

A receptor that binds to a G protein

Question 17

G Proteins

Answer 17

Proteins that bind to GDP and GTP. When it is bound to GDP; it is inactive and when bound to GTP; it is active

Question 18

Receptor Kinase

Answer 18

Enzymes that adds a phosphate group to another molecule through phosphorylation

Question 19

Phosphates

Answer 19

Removes a phosphate group through dephosphorylation. When a protein is phosphorylated, it is usually turned on; when it is not dephosphrotylated, it is usually turned off

Question 20

Second Messenegrs

Answer 20

Intermediate cytosolic signaling molecules

Question 21

Binding Affinity

Answer 21

The amount of time a signaling molecule remains bound to its receptor depends on how tightly the receptor holds on to it

Question 22

Dimerization

Answer 22

When a signaling molecule binds to the extracellular portion of the receptor, a conformational change causes the receptor to partner up with another receptor kinase bound to another molecule of the same ligand

Question 23

Ras

Answer 23

When bound to an activated receptor kinase, it releases GDP and binds GTP to become active

Question 24

MAP Kinase Pathway (Mitogen-Activated Protein Kinase Pathway)

Answer 24

A series of kinases that occur when activated GTP-bound Ras triggers the activation of a series of kinases

Question 25

Membrane Potential

Answer 25

The difference in electrical charge across the plasma membrane