Lecture 11: Cell Communication

Question 1

cell communication

Answer 1

occurs between cells via binding of molecular signals at the cell membrane

Question 2

cell signaling leads to ___

Answer 2

a response in the receiving cell

Question 3

what is a signal?

Answer 3

a molecule that when received, triggers a cellular response

Question 4

three types of responses

Answer 4

1. change in membrane
2. change in gene expression
3. change in metabolism

Question 5

3 Stages of Signal Transduction Pathway

Answer 5

1. reception of the signal
2. transduction of the signal
3. cellular response

Question 6

3 main types of signaling

Answer 6

1. endocrine: long distance signaling (through bloodstream)
2. Paracrine: signals diffuse to and affect nearby cells (ex: wound repair)
3. Autocrine: signals affect same cell that releases them

Question 7

Peptide Hormone

Answer 7

• made up of amino acids
• water soluble
• receptor in plasma membrane

Question 8

steroid hormone

Answer 8

• lipid soluble
• receptor inside cell nucleus
• diffuse freely because non polar
• changes gene expression

Question 9

endocrine system

Answer 9

synthesis and secretion of hormone signals

Question 10

what types of organelles would you expect in great number in endocrine cells?

Answer 10

• rough ER
• golgi apparatus
• secretary vesicles

Question 11

What changes the receptor?

Answer 11

the binding of signal

Question 12

reversible reaction

Answer 12

ligand will leave the receptor and turn off the signal

Question 13

membrane receptors

Answer 13

binding of signal molecules at cells surface

Question 14

binding of ligand results in

Answer 14

allosteric change in protein

Question 15

what could be a signal molecule that binds to an internal receptor?

Answer 15

steroids

Question 16

Ligand gated ion channels

Answer 16

change in membrane potential due to binding of ligand

Question 17

protein kinase receptors

Answer 17

activated receptor in a kinase which phosphorylates target proteins

Question 18

G-Protein linked receptors

Answer 18

signal activates the receptor to activate a G-Protein

Question 19

phosphorylation cascade

Answer 19

signaling cascade involves protein kinases, protein phosphates and ATP

Question 20

Secondary messengers

Answer 20

small non-polar relay molecules; amplify the signals

Question 21

synaptic signals

Answer 21

special type of signaling between neurons and other cells

Question 22

neurotransmitters

Answer 22

are a class of ligand whose function is to allow communication between neurons and other cells across the synapse

Question 23

The sodium-potassium pump of neurons pumps

Answer 23

Na+ out of the cell and K+ into the cell