cell signalling

Question 1

cell signalling

Answer 1

process of communication within intracellular

Question 2

function of cell signalling

Answer 2

respond to changes in environment
regulation and coordination of response between different cells and tissues within a multicellular organism

Question 3

ligands:signalling molecules

Answer 3

bind to receptors, can be proteins, peptides or amino acids

Question 4

receptor

Answer 4

protein molecules inside target cell or a surface which receives chemical signal -attached to membrane or cytoplasm

Question 5

effector protein

Answer 5

final target of signalling cascade -altered in response to the signal received in response to signal received causing a change in cell behaviour

Question 6

forms of signalling

Answer 6

-contact dependent
-direct cell to cell -depends on distance to travel to reach target cell

Question 7

paracrine signalling

Answer 7

attaches to target cells -called local mediators
-local mediators are secreted molecules

Question 8

synaptic signalling -specialised type of paracrine signalling

Answer 8

ligand which is a local region converted to neurotransmitters

Question 9

neurotransmitter

Answer 9

-specialised cells for communication over long distance as the axon of neurones can contact far away

Question 10

what happens when an impulse reaches end of synapse?

Answer 10

triggers release of chemical signal called neurotransmitter

Question 11

endocrine

Answer 11

signalling cells known as endocrine cell

Question 12

hormones

Answer 12

released ligand which release into blood stream and travel long distance to target cells

Question 13

function of hormones

Answer 13

chemical messenger which travels throughout the body coordinating complex processes examples:
-growth and development
-tissue function
-sexual function reproduction
-sleep and mood

Question 14

glands

Answer 14

group of cells that release hormones In blood stream

Question 15

endocrine system

Answer 15

collection of glands that produces hormones

Question 16

types of hormones

Answer 16

1.amines hormone
2.protein and peptide
3.steroids

Question 17

how do you identify the right cell?

Answer 17

1.have correct receptor for ligand to cause a response

Question 18

how does the signal molecule with high specificity help?

Answer 18

ensures receptor responds to appropriate signal and not the ones around the cell

Question 19

response depends on target cell, what does the same effector molecule lead to

Answer 19

response and multiple effects of a single molecule in different target cells

Question 20

different types of receptor

Answer 20

1.cell surface receptors
2.internal receptor
3.the lipid bilayer

Question 21

cell surface receptor

Answer 21

transmembrane protein on surface of target cell

Question 22

internal receptor

Answer 22

ligand crosses membrane to reach target cell through diffusing across the lipid bilayer

Question 23

structure of ligands lipid bilayer

Answer 23

small hydrophobic -diffuse across lipid bilayer of membrane

Question 24

ion channel-coupled receptors

Answer 24

rapid synaptic signalling between nerve + electrically excitable target cells

Question 25

what happens when small neurotransmitters bind to ion channels

Answer 25

open them allowing ions to move in and out allowing to trigger action potential

Question 26

what are G protein linked receptors made up of

Answer 26

alpha, beta +gamma subunits

Question 27

what does G protein bind to?

Answer 27

guanosine, triphosphate (GTP)

Question 28

what does G protein attach to?

Answer 28

guanoisne diphosphate -inactive

Question 29

what is activated when G protein attaches to nucleotide?

Answer 29

GTP

Question 30

what happens when a G protein couples receptors are activated +target protein?

Answer 30

activate an enzyme or ion channel, has interaction between activated receptor and target protein

Question 31

what does activation of target protein activate

Answer 31

activates second messenger and triggers a cascade of signalling event

Question 32

protein phosphorylation

Answer 32

reversible post translational modification of proteins where amino acid is phosphorylated by protein kinase with addition of phosphate group

Question 33

function of protein phosphorylation

Answer 33

important in cellular regulatory-enzymes and receptors are activated or deactivated by phosphorylation by means of kinases and phosphatases

Question 34

kinase

Answer 34

add phosphate to protein and phosphatase removes

Question 35

signalling dynamics-positive feedback

Answer 35

signal induces more itself to serve stability or prolonged signalling

Question 36

signalling dynamics-negative feedback

Answer 36

signal induces the expression of its own inhibitor which limits signalling