Cell communication

Question 1

Autocrine signaling

Answer 1

• A cell responds to its own signaling.

- Signaling molecules are released by a cell and then bind to receptors on the very same individual cell.

Question 2

Endocrine signaling

Answer 2

Molecules travel through the blood stream, have to act over long distances to reach receptor cells.
Ex) hormones, such as adrenaline.

Question 3

Paracrine signaling

Answer 3

Signaling by diffusion between two cells, short distance.

Question 4

Juxtacrine signaling

Answer 4

Contact dependent signaling.

Question 5

Signaling cell

Answer 5

Releases signaling molecules.

Question 6

Signaling molecule

Answer 6

Ligand

Question 7

Responding cell

Answer 7

Has receptor proteins that bind to the signaling molecule.

Question 8

G protein receptor

*fight or flight response

Answer 8

• The ligand (adrenaline) binds to the receptor.
• GDP is able to swap for GTP.
• G protein drops Beta and Gamma units and activates desired target protein.

Question 9

Ligand gated-ion channel

Answer 9

Ligands bind directly to the channel to open it.

Question 10

Cytokine

Answer 10

The cell signals! (proteins)

- Released from one cell and bind to another.

Question 11

Steps of cell response

Answer 11

1) Receptor activation: the signal binds to a receptor, which is then activated.
2) Signal transduction: the signal is transmitted to the interior of the cell by a signal transduction pathway.
3) The cell responds
4) Termination: the response is terminated so that new signals can be received.

Question 12

Receptor kinases

Answer 12

When ligands attach to two kinases, they phosphorylate (introduce a phosphate group to) each other, releasing a signal into the cell.
Ex) MAP kinase pathway: activated when receptor kinases signal through Was, which can mutate and lead to cancer.

Question 13

Receptor protein (receptor)

Answer 13

Binds to the ligand.