Secondary messengers

Question 1

Cyclic AMP

Answer 1

Activated by G protein
AC binds to GPCR
Catalyses AMP into cAMP
cAMP then interacts with PKA
PKA activates multiple enzymes 
PDE breaks down cAMP to AMP to stop PKA

Question 2

Use of cAMP

Answer 2

cAMP RELAXES SMOOTH MUSCLE in bronchial(drug used in increased cAMP for asmtha) AND INCREASES GLYCOGEN METABOLISM

Question 3

What cAMP affects

Answer 3

Activates calcium ion pump and channels
Activation of potassium ion channels
Desensitisation
Glycogen metabolism

Question 4

Glycogen metabolism

Answer 4

This causes increase in glucose in the blood which is required when exercising
Epinephrine and glucagon is needed to activate cAMP for glycogen metabolism

Question 5

PIP2(phosphoinositides)

Most likely to come up

Answer 5

It stimulates calcium ion release and generate IP3, PKC and tyrosine kinase
is an essential lipid involved in metabolic processes

Question 6

pip2 structure

Answer 6

Has a hydrophobic tail and hydrophilic Tail

Question 7

PIP2

Answer 7

PI gets catalysed by a PI4 Kinase adds a phosphate group on the 4th carbon which makes a PI4 phosphate/PIP
PIP Kinase 5 synthesises for PIP2
PIP2 can be metabolised or derogated
it is made into DAG or IP3

Question 8

IP3

Answer 8

IP3 combines to IP3 receptor and receptor opens its pore and is released into cytosol and bind to inactive PKC
DAG and calcium ion will activate the PKC which catalyses many other chemical reactions downstream.

Question 9

Calcium

Answer 9

Calcium is a signal messenger of multiple regulations
It can enter through calcium channels increase the concentration in cells
ER stores lots of calcium
When ip3 is activated it releases calcium in cells

Question 10

Calcium cellular processes

Answer 10

Muscle contraction
Gene expression
Synaptic transmission
secretion

Question 11

Calcium sensors and effectors

Answer 11

It is responsible for detecting and activating channels
CA2+is important to detect intracellular calcium
Calcium effector is when the increased calcium can target to change the function

Question 12

Calcium sensors(Calmodulin)` structure

Answer 12

Lobes bind to 2 different calcium ions but bind with different affinities
N and C lobe
Smaller kd means higher binding affinity
Calcium binding changes the structure of calmodulin

Question 13

CAMKII

Answer 13

It causes CamkII that is responsible for learning and memory

Undergoes auto phosphorylation to remain active

Question 14

Calcineurin

Answer 14

This can dephosphorylise the NFAT to stop transcription

With the phosphate group on the NFAT(causes immune response) it is inactive

Question 15

Calcium homeostasis

Answer 15

Enters via voltage and ligand channels
Can be removed into mitochondria or out of cell
Calcium pump removes it(ATP)
Sodium calcium pump removes it(1 ca2+ out 3 na+ in)

Question 16

Store operated calcium entry

Answer 16

process by which the emptying of ER calcium stores causes influx of calcium across the plasma membrane
Mediated by CRAC

Question 17

Stromal interaction molecule

Answer 17

Stromal interaction molecule is a protein that sensors calcium in the ER membrane and when there is depletion of ER membrane there is clustering

Question 18

Protein Kinase C

Answer 18

IT is a multimember family with about 15 lysozyme
Activated by PIP2
Requires PS to be activated