drugs -enzymes & transportrs Flashcards
define enzyme inhibitor
a molecule that binds to an enzyme and decreases its activity. It prevents the substrate from entering the enzyme’s active site and prevents it from catalysing its reaction.
what are the 2 types of enzyme inhibitor
irreversible inhibitors
reversible inhibitors
how do irreversible inhibitors work
react with the enzyme and change it chemically (e.g. via covalent bond formation)
how do reversible inhibitors work
bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind to the enzyme, the enzyme-substrate complex, or both.
can enzymes be drug products
yes
eg steptokinase and tPA clot busters
what are statins also known as
enzymes called HMG-CoA reductive inhibitors
what do statins do
block the rate limiting step in the cholesterol pathway
they are a class of lipid lowering medications that reduce the levels of bad cholesterol
for the primary prevention of cardiovascular disease
what is angiotensin converting enzyme inhibitor caused for
to regulate blood pressure
it does this by increasing blood pressure by increasing the amount of salt and water the body retains
inhibiting ACE reduces ATII production and therefore causes a reduction in blood pressure
where is angiotensin converting enzyme predominately found
kidney and liver
how is angiotensin converting enzyme hijacked
SARS-Cov2 uses ACE2 as an entry receptor to get into body cells
because ACE 2 has a diff distribution to ACE
symptoms of parkinson’s
• Hypokinesia – motor movement↓
• Tremor at rest
• Muscle rigidity, Motor inertia
• Cognitive impairment
• Degenerative disease of basal ganglia
Major dopaminergic pathways in CNS (red)
dopamine
• Early degeneration of dopaminergic neurones in the nigrostriatal pathway leading to autonomic dysfunction and dementia
what is L dopa produced from
produced from the amino acid L - Tyrosine as a precursor for neurotransmitter biosynthesis
it crosses the blood brain barrier
what is the blood brain barrier
a highly selective semi permeable membrane barrier that separates the circulating blood from the brain
what does peripheral DDC INHIBITOR DO
blocks DDC in the periphery generating more for the CNS pathway
if you block this more L -DOPA transfers into the brain - less dopamine being produced - has no effect outside of the brain
what does the peripheral COMT inhibitor do
prevents breakdown of L DOPA generating more for the CNS Pathway
what does central COMT INHIBITORS DO
FUNCTION WITHIN THE cns TO keep dopamine levels up
what do mono amino oxidase B inhibitors do
prevent dopamine breakdown and increases availability
what do central dopamine receptor agonists d
antagonise dopamine receptors ( not enzyme inhibitors )
what are the 2 categories of transporters
passive - no energy
active - require energy
2 types of passive transporters
symporter - Na/K/2Cl, NaCl
channels - Na, Cl, Ca, K
what is transport
when molecules move across a cell membrane
what is active transport
when ions move from a lower concentration to a higher concentration
allows cells get wat they need eg ions, glucose & amino acids
needs energy - usually from ATP
ATP —> ADP/AMP
3 types of protein ports
uniporters
symporters
anitporters
