Unit 5-Cell Communication

Question 1

Ligand

Answer 1

on, particle, or molecule that binds to a receptor which then activates a change in cellular responses

Question 2

Receptor

Answer 2

a protein that binds to a specific ligands

Question 3

Single Transduction

Answer 3

when a ligand binds to a receptor

Question 4

Autocrine

Answer 4

when the cell “talk” to themselves to know what it needs to do either divide or to not divide

Question 5

Paracrine

Answer 5

which is when adjacent target cells “talk” to each other about dividing and not dividing

Question 6

Endocrine

Answer 6

communicate throughout the whole body

is when hormones are secreted into the bloodstream by endocrine glands which happens during puberty.

Question 7

Synaptic

Answer 7

are when neurotransmitters are binded with target cells communication through the nervous system

Question 8

Direct Contact

Answer 8

gap junctions which are a bunch of membrane proteins that bind to adjacent cells that diffuse into cells to communicate

Question 9

What are the two types of mechanisms for cell communication?

Answer 9

membrane bound receptors

soluble receptors

Question 10

Soluble receptors

Answer 10

a ligand can pass through a membrane protein because it is lipophilic and is small

they are called cytoplasmic receptors or nuclear receptors

lipophilic ligands: steroids, vitD, prostaglandis, T3&T4

Question 11

What are the three forms of membrane bound receptors?

Answer 11

ion channel linked receptors
G-protein coupled receptors
enzymatic receptors

Question 12

ion channel linked receptors

Answer 12

bind a ligand and open a channel through the membrane that allows specific ions to pass through.
ex:

Question 13

g-protein coupled receptors

Answer 13

a ligand is binded to a recepter which causes its alpha and beta subunits to dissociate and then the G protein is activated by GTP which binds to an effector protein of adenylyl cyclase or phospholipase C which make secondary messegers like cAMP, cGMP,Ca++ and IP3

Question 14

cAMP mediated signal transduction

Answer 14

the effector protein of adenylyl cylase is activated and activates pKa (a kinese) which change physiology of the cell the and the kinase is phophorylated

Question 15

Ca++/IP3 mediated signal transduction

Answer 15

phospholipase C is activated which makes IP3 and binds to a IP3 gated calcium ion channel on the endoplasmic reticulum and calcium is then activaes a suit of proteins

Question 16

How is a second messenger system inactivated?

Answer 16

by GDP binding to an alpha subunit of a G-protein
phosphodiesterase to a hydrolyze cAMP and cGMP
phosphotase to dephosphorylate proteins
an active transport of calcium ions into the ER

Question 17

kinase receptors

Answer 17

receptor tyrosine kinase (RTK) proteins bind to ligands which adds a phosphate to a protein (phosphorilated)

Question 18

How are kinases inactivated?

Answer 18

RTK are inactivated due to internalization and phosphatase by removing phosphates