Chapter 11: Cell Communication

Question 1

Cell Communication

Answer 1

How cells transmit information and respond to this information

Question 2

Signal Transduction Pathway

Answer 2

A series of steps by which a signal received on a cell’s surface is converted into a specific response by the cell

Question 3

Chemical Messengers

Answer 3

Substances that carry messages from one cell to another in a multicellular organism. A ligand

Question 4

Cell Junction

Answer 4

Points that connect the cytoplast of two cells by binding the cells together and forming gaps in the membrane

Question 5

Local regulator

Answer 5

A messenger molecule that travels a short distance to carry its message

Question 6

Hormones

Answer 6

Messenger molecules that travel a long distance within an organism

Question 7

Three Stages of Cell Signaling
(that the receiver cell goes through)

Answer 7

-Reception: Ligand binds to cell receptor
-Transduction: Signal transduction pathway
-Response: the actual response as a result of the signal

Question 8

Reception

Answer 8

A SPECIFIC signal molecule / ligand / chemical messenger binds to ITS RESPECTIVE receptor in or on a cell.
The receptor will usually change shape to transmit the signal

Question 9

Three main types of membrane receptors

Answer 9

-*G protein-coupled receptors
-Receptor tyrosine kinases
-*Ion channel receptors

Question 10

G protein-coupled receptor

Answer 10

Activates a G protein by phosphorylizing its GDP into GTP. Activated G protein now goes on to activate another protein, usually an enzyme

Question 11

Signaling Molecules that use g-protein coupled receptors (three examples

Answer 11

-Yeast mating factors
-Epinephrine
-Rhodopsin (is a receptor)

Question 12

Ligand-gated ion channel receptor

Answer 12

When this receptor binds to a ligand, it changes shape and functions as a channel protein for ions. Ions enter the cell to trigger the cellular response

Question 13

Intracellular Receptors

Answer 13

Receptors found in the cytosol or nucleus of a target cell.
Small or hydrophobic messengers can cross the membrane easily.
Think steroids & thyroid hormones.

Question 14

How do hormones impact gene expression?

Answer 14

Enter the cell, bind to receptor protein to form hormone-receptor complex, then enters the nucleus through nuclear pores

Question 15

Protein Kinase

Answer 15

Part of the “Signal Transfer Pathway” that transfers a phosphate from ATP onto another protein (phosphorylation). Often activates another protein kinase, which then activates another, etc until final intended activation

Question 16

Protein Phosphatase

Answer 16

Dephosphorylates proteins (removes a phosphate from them)