W2 Cell Signalling

Question 1

why do cells need to signal

Answer 1

cell death/growth
metabolism
secretion

Question 2

how do cells communicate

Answer 2

by ligands binding onto receptors

Question 3

what is autocrine signalling

Answer 3

signal from cell to itself

Question 4

what is paracrine signalling

Answer 4

signal from cell to its direct neighbour
short distances usually with the same tissue

Question 5

what is endocrine signalling

Answer 5

signal from cell to another cell at a large distance
gland secretes a hormone into circulatory system

Question 6

what is neuronal signalling

Answer 6

signal via the nervous system
travel as electrical impluses

Question 7

what are the steps to indirect cell signalling diffusion

Answer 7

molecules are secreted into an aqueous fluid
molecules transported over a range of distances to bind a target receptor
binding of the signal causes a response in the target cell

Question 8

what is an example of paracrine signalling

Answer 8

inflammatory responses

Question 9

how does Gap Junction Signalling work

Answer 9

• signals pass via gap junctions to enter cells
• pass through a connexon (made of 6 connexins)

Question 10

what is Juxtracrine Signalling

Answer 10

signalling without movement of ligands

Question 11

what are the 4 hydrophilic signal molecules

Answer 11

Peptides
Purines
Gases
amines

Question 12

what are the 3 hydrophobic signal molecules

Answer 12

lipids
steroids
amines

Question 13

where do hydrophobic signals bind to

Answer 13

bind to intracellular receptors

Question 14

which 3 AAs can functin as neurotransmitters

Answer 14

Aspartic Acid
Cysteine
Glutamic Acid

Question 15

how is GABA formed

Answer 15

via decarboxylation of glutamic acid

Question 16

what are Biogenic Amines

Answer 16

molecules with amine group derived from AAs

Question 17

what are catecholamines and an example

Answer 17

derivatives of Tyrosine and are hydrophilic
dopamine

Question 18

what are Indoleamines and an example

Answer 18

derivatives of tryptophan and are hydrophilic
serotonin (5HT)

Question 19

what are steroids derivatives of

Answer 19

cholestrol

Question 20

what are some properties of steroids

Answer 20

lipophilic
hydrophobic

Question 21

how are the binding of steroids regulated

Answer 21

by the laws of mass action and mass action equilibriums

Question 22

what does prostaglandins do and how

Answer 22

mediators in inflammatory cascade activate after binding of COX1

Question 23

How do nuclear receptors differ from transmembrane receptors

Answer 23

bind hydrophobic ligands that enter the cell directly

Question 24

What do nuclear receptors do once activated

Answer 24

bind DNA directly and act as ligand-dependent transcription factors

Question 25

How do nuclear receptors modify gene expression

Answer 25

add or remove acetyl groups from histones

Question 26

What does Bone Morphogenetic Protein signaling (BMPs) do for the body

Answer 26

regulates development and cellular differentiation

Question 27

What type of receptor uses the JAK-STAT pathway

Answer 27

Enzyme-linked receptors

Question 28

How does JAK-STAT signaling work

Answer 28

- binding of ligand activates JAKs - phosphorylate STAT proteins to promote transcription

Question 29

what are the 3 components of signalling

Answer 29

transmitter a channel a receiver

Question 30

how to make signals more reliable and stronger

Answer 30

amplification

Question 31

what are the steps to lateral inhibition

Answer 31

primary cell will signal surrounding cells by producing delta protein signals to notch receptors and inhibits delta and primary fate

Question 32

what does notch intracellular domain do

Answer 32

signal to inhibit primary fate and delta protein production

Question 33

how are heads split from tails of fruit flies

Answer 33

bicoid mRNA tethers to anterior and nanos mRNA is tethered to posterior

Question 34

what signal determines where digits of chicks form

Answer 34

sonic hedgehog signalling

Question 35

how would cells get more accurate positioning

Answer 35

include more gradients

Question 36

how are turing patterns formed

Answer 36

complex interactions with other signals