Chemistry of Signalling Metals Flashcards Preview

Pharmacy Stage 2 > Chemistry of Signalling Metals > Flashcards

Flashcards in Chemistry of Signalling Metals Deck (18)
Loading flashcards...
1
Q

where are metals found in the periodic table?

A

alkali metals: group 1
alkaline earth metals: Group 2
transition metals: d-block

2
Q

what processes are metal ions essential for?

A
  • transcription
  • translation
  • signalling
  • transport
  • catalysis
3
Q

what are sodium, potassium and calcium essential for?

A

neuronal signalling with Na and K helping with transfer along the neurone and Ca helps with passing signals from one neurone to the other

4
Q

how do Na+ and K+ help to transmit signals along a neurone (action potential)?

A
  • at resting potential (-70mV) there is a great positive charge outside the cell than inside due to high Na+ conc outside. Inside there are K+ and negatively charged proteins.
  • sodium channels are closed when the neurone is at rest and becomes opens when activated to bring in Na+ ions (depolarisation)
  • this increases the potential of the cell to -40mV.
  • more Na+ channels open further down the neurone passing the signal all the way down the axon.
  • Na+ channels then close and more K+ channels open to move K+ out of the cell to make the cell more negatively charged. (repolarisation)
  • hyperpolarisation occurs when the cell lets out too many K+ ions so potential falls below resting potential.
  • K+ ion channels and Na+/K+ channels correct this to return the membrane to resting potential. Na+/K+ channels bring 3Na+ out of and take 2K+ into the cell.
5
Q

how doe calcium channels help to transmit signals between neurones?

A
  • action potential depolarises axon terminal
  • depolarisation opens voltage-gated Ca2+ channels so Ca2+ enters the cell
  • this triggers exocytosis of synaptic vesicles (i.e. they fuse with the cell membrane.
  • neurotransmitter diffuses out the vesicles into the synaptic cleft then binds to the receptors on the postsynaptic cell
  • this binding causes a response in the postsynaptic cell
6
Q

what is the role of Ca2+ in meiosis?

A

-it activates the ovum after sperm fertilisation

7
Q

what is the role of Ca2+ in mitosis?

A
  • high Ca2+ conc during metaphase-anaphase transition

- suggests calcium has a role in signalling anaphase

8
Q

what is the main role of magnesium?

A

acts a co-factor aiding the reactivity of others

9
Q

what can result from inadequate Mg intake?

A

muscle spasms, cardiovascular disease, osteoporosis, diabetes, high blood pressure, anxiety disorders, migraines, cerebral infarction

10
Q

what is the role of Mg in DNA and RNA?

A

to stabilise the DNA or RNA in the cellular environment by neutralising the negatively charged phosphate groups

11
Q

what role does Mg have on insulin?

A

-it helps in the tyrosine-kinase activity, which promotes insulin activity.

12
Q

what is the role of manganese?

A

it is a cofactor and particularly important in the detoxification of superoxide free radicals in organisms that deal with elemental oxygen

13
Q

what can happen with high levels of manganese in the system

A
  1. manganism-condition that leads to neurological damage and is sometimes irreversible
  2. neurodegenerative disorders can arise from high manganese levels causing dopaminergic neuronal death and symptoms related to Parkinsons disease
14
Q

what does arginase do?

A

catalyses the 5th and final step in urea cycle

15
Q

What is superoxide dismutase (SOD) and what does it do?

A

an enzyme

-catalyse the dismutation (partitioning) of the superoxide (O2-) radical into oxygen or hydrogen peroxide

16
Q

how are superoxides produced?

A

as a bi-prouct of oxygen metabolism and causes cell damage

17
Q

hydrogen peroxide is damaging, how is it degraded in the body?

A

by enzymes e.g. catalase

18
Q

where are manganese SOD’s present?

A

in nearly all mitochondria

Decks in Pharmacy Stage 2 Class (85):