cell communication/transduction

Question 1

direct contact

Answer 1

cells must be touching

animals: gap junctions
plants: plasmodesmata

immune cells (antigens)

Question 2

local regulators

Answer 2

messages travel a short distance

paracrine & synaptic signaling

Question 3

long distance signaling

Answer 3

hormones

endocrine signaling

circulatory (insulin)

Question 4

3 stages of cell signaling

Answer 4

1) reception

2) transduction

3) response

Question 5

stage 1: reception

Answer 5

ligand binds to receptor and activates it

initiates transduction signal

Question 6

plasma membrane receptors

Answer 6

most common

bonds to large, polar ligands

can’t go through membrane

Question 7

intracellular receptors

Answer 7

found in cytoplasm or nucleus or target cell

travels through plasma membrane

Question 8

stage 2: transduction

Answer 8

conversion of extracellular signal to an intracellular signal that will bring about a response

Question 9

phosphorylation vs dephosphorylation in cells

Answer 9

phosph: relays signal

dephosp: shuts off pathways

Question 10

second messengers

Answer 10

signal is amplified

help relay message and amplify response

Question 11

stage 3: response

Answer 11

converts signal to a response

alters cell processes

Question 12

2 main membrane receptors in animals

Answer 12

GPCRs: GDP -> GTP, G protein is inactive until bonded to GPCR

ion channels: gate opens or closes when ligand binds to receptor