CELL SIGNALING

Question 1

Cell to cell communication enables the body to coordinate…

Answer 1

-Growth & development
-Repair
-Renewal (replacement)
-Defense
-Response to environmental stimuli

Question 2

What two factors enable cell to cell communication?

Answer 2

Signals (ligands) and receptors

Question 3

A signal is a

Answer 3

Ligand

Question 4

Types of receptor molecules

Answer 4

-G Protein Coupled Receptors (GPCR)
-Tyrosine Kinase Receptors (RTK)
-Histidine Kinase Receptors
-Ligand gated ion channel receptors
-Riboswitches (RNA molecules)

Question 5

______ recognize the ligand.

Answer 5

Receptors

Question 6

G Protein Coupled Receptors (GPCR) enable your cells to…

Answer 6

Recognize Go-Signals and other signal types

Question 7

GPCRs are required for…

Answer 7

-Cell cycle regulation
-Immunity
-Sensory stimuli
-Hormone and neurotransmitter perception

Question 8

What are the steps after the signal binds to the GPCR?

Answer 8

1. signal binds to the GPCR
2. G Protein is activated
3. Activated G Protein initiates the cellular response
4. The G Protein must be deactivated to prevent abnormal signaling

Question 9

~30-60% of all pharmaceuticals adjust….

Answer 9

G Protein activity

Question 10

G Protein function is essential for

Answer 10

Cell signaling and human health

Question 11

Many cancers are due to _________ G Proteins

Answer 11

Constitutive (always activated - the cell doesn’t stop dividing)

Question 12

Your cells use ______ to recognize Go-Signals and other signal molecules

Answer 12

RTKs (tyrosine kinase receptors)

Question 13

Signal binding to two RTKs activates…

Answer 13

Their kinase enzyme part

Question 14

Two activated RTKs interact and phosphorylate each other to…

Answer 14

Initiate the cellular response

Question 15

The activated RTKs must ______ to prevent abnormal cell signaling

Answer 15

Deactivate

Question 16

RTK phosphatases ____________ the RTKs

Answer 16

Dephosphorylation (PO4 group removal)

Question 17

Active RTKs are _______ and _______ in the lysosome

Answer 17

Imported and degraded
Stops signal response

Question 18

RTK abnormalities cause some cancers

Answer 18

-Constitutive (always on) RTK receptors
-Excess number of RTK receptors in the cell membrane

Question 19

Cells must recognize ______ and _______ signals

Answer 19

Hydrophilic and hydrophobic signals

Question 20

Hydrophilic signal molecules

Answer 20

-Cannot pass through the cell membrane
-Located in the surrounding extracellular fluid/cell surface
-Cells use receptors embedded in the cell membrane to recognize external hydrophilic signals

Question 21

Hydrophobic signal molecules

Answer 21

-Directly pass through the cell membrane
-Cells use an intracellular receptor to recognize external hydrophobic signals

Question 22

Signal transduction pathways enable the cell to

Answer 22

Respond to a signal recognized by a receptor

Question 23

After the signal binds to the receptor…

Answer 23

The activated receptor stimulates the signal transduction pathway in the cell

Question 24

What is the signal transduction pathway?

Answer 24

It is the sequence of biochemical events induced in the cell after signal recognition
It connects signal perception to the proper cellular responses

Question 25

The signal transduction pathway instructs the cell to...

Answer 25

Produce the proteins required to respond to the signal

Question 26

The kinase phosphorylation cascade

Answer 26

A series of phosphorylation reactions that forms many signal transduction pathways

Question 27

The activated receptor induces the

Answer 27

Kinase phosphorylation cascade in the cell

Question 28

The kinase phosphorylation cascade magnifies

Answer 28

Signal perception within the cell to increase the probability of the proper cell response

Question 29

Scaffolding proteins position

Answer 29

All the receptors and signal transduction proteins to enable efficient cell signaling

Question 30

Scaffolding proteins organize all

Answer 30

Signaling components into a functional cellular complex