Cell Communication

Question 1

Epinephrine

Answer 1

• both a transmitter and a hormone
• adrenaline

Question 2

What did Sutherland discover?

Answer 2

how the hormone epinpherine acts on cells

Question 3

Sutherland suggested that cells went through what 3 processes?

Answer 3

• Reception
• Transduction
• Response

Question 4

Reception

Answer 4

the target cell detects a signaling molecule that binds to a receptor protein on the cell surface

Question 5

Transduction

Answer 5

the binding of the signaling molecule alters the receptor and initiates a signal transduction pathway

• this offers different pathways and outcomes
• we can reuse parts of the pathway

Question 6

Response

Answer 6

In response, the transduced signal triggers a specific response in the target cell

Question 7

How do cells respond?

Answer 7

They can choose to replicate, undergo apoptosis, and more.

Question 8

Paracrine Signaling

Answer 8

allows cells to communicate with each other by releasing signaling molecules that bind to and activate surrounding cells.

• locally released

Question 9

Synapse Signaling

Answer 9

A type of paracrine signaling in which nerve cells transmit signals. This process is named for the synapse, the junction between two nerve cells where signal transmission occurs.

• cell to cell

Question 10

Neurotransmitters

Answer 10

a signaling molecule transported through a synapse

Question 11

Synapse

Answer 11

the junction between two nerve cells

Question 12

Endocrine Signaling

Answer 12

the signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites.

• sends signals to everywhere in your body

Question 13

Pheromones

Answer 13

substances which are secreted to the outside by an individual and received by a second individual of the same species

Question 14

Ligand

Answer 14

specific molecule that fits receptor

Question 15

What signifies the first transduction of the signal?

Answer 15

shape change in a receptor

Question 16

What are the most common signal receptors?

Answer 16

plasma membrane proteins

Question 17

What are the three main membrane proteins

Answer 17

• G protein coupled receptors
• Receptor tyrosine kinases
• Ion channel receptors

Question 18

G protein coupled receptors

Answer 18

are
cell-surface transmembrane receptors that work
with the help of a G protein

Question 19

G proteins

Answer 19

• similar in structure and bind the energy-rich GTP

Question 20

Ligand Gated Ion Channel

Answer 20

• acts as a gate that opens and closes when the receptor changes shape

When a signal molecule binds as a ligand to the receptor, the gate allows specific ions, such as Na+ or Ca2+, through a channel in the receptor

Question 21

Receptor tyrosine kinases

Answer 21

membrane receptors that transfer phosphate groups from ATP to another protein

• cannot trigger multiple pathways

Question 22

What is abnormal functioning of RTKs?

Answer 22

associated with many types of cancers

Question 23

What type of messengers go through the cell membrane?

Answer 23

Small or hydrophobic chemical messengers can readily cross the membrane and activate receptors

Question 24

Example of Hydrophobic Chemical Messenger?

Answer 24

steroid and thyroid hormones of animals

Question 25

Transduction Pathway

Answer 25

Activation to Response

Question 26

how do we activate an an enzyme and proteins

Answer 26

add a phosphate to ATP

Question 26

Do enzymes get used up or only act on one protein?

Answer 26

No they do not get used up and no they do not act on only one protein.

Question 27

Kinases

Answer 27

enzymes that activate other enzymes *turns on

Question 28

Phosphorylation Cascade

Answer 28

a sequence of signaling pathway events where one enzyme phosphorylates another, causing a chain reaction leading to the phosphorylation of thousands of proteins.

Question 29

Protein Phosphatases

Answer 29

rapidly remove phosphates and deactivates enzymes

Question 30

Secondary Messengers

Answer 30

small, nonprotein, water-soluble molecules or ions that spread throughout a cell by diffusion

Question 31

Cyclic AMP

Answer 31

- usually activates protein kinase A, which phosphorylates various other proteins

Question 32

Adenyl Cyclase

Answer 32

an enzyme in the plasma membrane, converts ATP to cAMP in response to an extracellular signal

Question 33

Components of CAMP pathway

Answer 33

Other components of cAMP pathways are G proteins, G protein-coupled receptors, and protein kinases

Question 34

What secondary messengers release calcium?

Answer 34

Inositol triphosphate (IP3) Diacylglycerol (DAG)

Question 35

What are the four ways to regulate signals?

Answer 35

Amplification of the signal (and thus the response) Specificity of the response Overall efficiency of response, enhanced by scaffolding proteins Termination of the signal (prevent apoptosis)