Cell Communcation

Question 1

Essential elements for cell communication-

Answer 1

Signalling cell
Grow+Divide
Differentiate
Die

Question 2

In bacterial cells, the signalling peptide binds to the receptor to uptake DNA when…

Answer 2

Population density is high

Question 3

4 steps in cell signalling

Answer 3

1. Receptor activation
2. Signal transduction
3. Response
4. Termination

Question 4

The signal binds to a receptor, which is activated

Answer 4

Receptor activation

Question 5

Signal is transmitted to the interior of the cel by a signal transduction pathway

Answer 5

Signal transduction

Question 6

The cell responds

Answer 6

Response

Question 7

The cell is terminated so that new signals can be received

Answer 7

Termination

Question 8

Signalling molecules through he bloodstream over distance

Answer 8

ENDOCRINE

Question 9

Involves cell communication close to eachother, short distance to the neighbouring cells receptor

Answer 9

PARACRINE

Question 10

Signalling cell and responding cell are the same.

-Embryology

Answer 10

AUTOCRINE

Question 11

Uses direct contact between neighbouring cells in absence of signalling molecule

Answer 11

CONTACT-DEPENDENT

Question 12

Small nonpolar signalling molecules can pass freely through the plasma membrane and activate cytoplasmic receptor

Answer 12

Intracellular receptors

Question 13

A receptor molecule undergoes a ….., activating a receptor

Answer 13

Conformational change

Question 14

When a G protein is bound to GTP

Answer 14

ACTIVE

Question 15

When a G protein is bound to GDP

Answer 15

INACTIVE

Question 16

When a ligand binds to a G protein-coupled receptor, it activates the G protein by…

Answer 16

Replacing GDP—-> GTP

Question 17

Enzyme that adds a phosphate group to another molecule

Answer 17

Kinase

Question 18

When a protein is phosphorylated

Answer 18

Active

Question 19

Alter the flow of ions across the plasma membrane

Answer 19

Ion channels

Question 20

G proteins are composed of…

Answer 20

Alpha
Beta
Gamma

Question 21

When 3 subunits are joined….

Answer 21

G protein INACTIVE

Question 22

What causes b to separate from gamma?

Answer 22

GDP ——> GTP

Question 23

GTP- bound alpha subunit…

Answer 23

ACTIVE

Question 24

Adrenaline is amplified in 3 places…

Answer 24

1) Adrenaline bound receptor activates multiple G proteins
2) Each adenylyl cyclase produces cAMP
3) Each kinase A activates multiple protein targets

Question 25

Terminating G protein involves…

Answer 25

Converting GTP——>GDP

Question 26

Phosphataeses

Answer 26

Remove phosphate groups from activated proteins=inactive

Question 27

Used in formation of limb buds, insulin signalling and would healing

Answer 27

Receptor Kinase

Question 28

Responsible for pigment in skin, feathers, hair extensions…

Answer 28

Kit

Question 29

Dimerization

Answer 29

Receptor Kinase
Single signalling molecule binds with extracellular protein with 2 receptors
Causes receptors to pair

Question 30

Activates the cytoplasmic kinase domains to cause phosphorylation to the tails

Answer 30

Dimerzation

Question 31

Phosphorylated areas provides a place for proteins to…

Answer 31

Bind and become active

Question 32

MAP Kinase Pathway steps (5)

Answer 32

• PDGF and platelets released. PDGF bind to PDGF receptor kinases and dimeraze to become active
• phosphorylated receptors signal other proteins
• Ras activates
• Kinases enter nucleus to regulate transcription
• GTP—->GDP inactive

Question 33

30% of cancer mutation due to…

Answer 33

Ras

Question 34

…. can take place at every step of cell communication

Answer 34

Cancer