Chemistry of Signalling Metals Flashcards
What are all Na+, K+ + Ca2+ involved in?
Neuronal signalling
What are Na+ + K+ involved in?
Signal transfer along the neurone
Describe electrical signalling
Na+ concentrated outside
K+ concentrated inside
Ionic charge between inside + outside unequal
Inside is negative to outside
Describe the events at the synapse
AP depolarises the axon terminal
Depolarisation opens voltage-gated Ca2+ channels
Ca2+ enters the cell
Ca2+ triggers exocytosis of synaptic vesicle contents
Neurotransmitter diffuses across synaptic cleft
Binds to receptors on postsynaptic cell
Initiates a response in postsynaptic cell
What is Ca2+ important in?
Meiosis + mitosis
How is Ca2+ important in meiosis?
Activates the ovum after sperm fertilisation
How is Ca2+ important in mitosis?
Rapid elevation of Ca2+ at metaphase-anaphase transition
What does Mg act as?
Cofactors = aids reactivity of others
What can inadequate intake of Mg cause?
Muscle spasms
What is an example of a process that requires Mg?
Glycolysis
What does intracellular Mg play a role in?
Regulating insulin action
What are manganese enzymes essential in?
Detoxification of superoxide free radicals
What are the classes of enzymes that have cofactors in?
Oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, lectins + integrins
What does arginase do?
Catalyses the final step in the urea cycle
Where the body disposes of harmful ammonia
What is superoxide dismutase?
Enzyme that catalyses the dismutation of superoxide radical into O or hydrogen peroxide
