Question 1

How do cells communicate?

Accepted Answer

Generating, transmitting, receiving, and responding to chemical signals

Question 2

What is cell signaling?

Accepted Answer

Process of cells communication with each other in the body

(driven by the release of ligands which are detected by receptors)

Question 3

What is a ligand?

Accepted Answer

Any type of signalling molecules that cells use to communicate

(detected by receptors)

Question 4

What are receptors?

Accepted Answer

Proteins on cells that ligands bind to

(can be located on the cell membrane for hydrophilic ligands, or inside the cell for hydrophobic ligands that are small enough to cross the membrane)

Question 5

What is direct cell-to-cell signaling?

Accepted Answer

Type of cell signaling that involves direct physical contact between cells during communication

(signaling molecules flow through water-filled channels; gap junctions in animal cells and plasmodesmata in plant cells)

Question 6

What is paracrine signaling?

Accepted Answer

Type of signaling where cells are close to each other and release a short-lived signal that will induce changes in a nearby cell

(especially important during development; only works over short distances)

Question 7

What is synaptic signalling?

Accepted Answer

Unique example of paracrine signaling, where nerve cells transmit ligands called neurotransmitters over the synapse

Question 8

What is autocrine signaling?

Accepted Answer

Type of signaling where the cell signals to itself, releasing a ligand that binds to its own receptors

(in many cases a signal can be both autocrine and paracrine; important in cancer)

Question 9

What is endocrine signaling?

Accepted Answer

Type of cell signaling where distant cells communicate using hormones that are transmitted through the bloodstream

Question 10

What happens after a ligand binds to a receptor on a cell?

Accepted Answer

The cell relays the message through a series of reaction, creating a response from the cell

Question 11

What is a signal transduction pathway?

Accepted Answer

A chain of molecules that relay signals inside cells

Question 12

What are kinases?

Accepted Answer

Enzymes that catalyze the phosphorylation of proteins

(catalyze the addition of phosphate groups to proteins)

Question 13

What are phosphatases?

Accepted Answer

Enzymes that catalyze the dephosphorylation of proteins

(catalyze the removal of phosphate groups from proteins)

Question 14

Why are kinases and phosphatases important?

Accepted Answer

They can often be used to turn on/off proteins

(many proteins are activated when phosphorylated by kinases, and deactivated when dephosphorylated by phosphatases)

Question 15

Why is calcium important for cell signaling?

Accepted Answer

Some proteins have binding sites for calcium and change shape/function when calcium binds

(calcium is used in muscles to start muscle contraction; calcium=)

Cell Communication, AP Biology Flashcards