Drugs - Enzymes and Transporters Flashcards
what is an enzyme inhibitor
Molecule binding to the enzyme and decreasing its activity. Does this by preventing substrate from entering the enzyme’s
active site and preventing from catalysing the reaction
What are the 2 types of enzyme inhibitor and what they do
IRREVERSIBLE INHIBITOR
-react with the enzyme and chemically alter it
REVERSIBLE INHIBITOR
-bind non-covalently, and different types of inhibition are produced depending on whether these inhibitors bind to the enzyme, enzyme-substrate complex or both
describe what a statin is by
-what pathway it inhibits
-is it primary or secondary
prevention against CVD
-What type of cholesterol it inhibitys
-cholesterol
-primary
-LDL
Inhibiting ACE (angiotensin converting enzyme) reduces _________ production and therefore causes a ________ in blood pressure
angiotensin 2, decrease
List the 6 symptoms of parkinsons
-Hypokineria (decreased motor movement)
-tremors at REST
-Cognitive impairment
-degenerative disease of the basal ganglia
-early degeneration of DOPAMINERGIC NEURONS in the nigrostriatal pathway causing autonomic dysfunction and dementia
Define Uniporter, symporter and antiporter
UNIPORTER
-uses enery from ATP to pull molecules in
SYMPORTER
-uses movement in of one molecule to pull in another against conc grad
ANTIPORTER
-one substance moves against grad, using enrgery from second substrate (NA, K, H) moving down its gradient
Give an example of a symporter and how it works
Na-K-Cl cotransporter (NKCC)
-protein that transports NA, k and Cl into cells
-moves ions in the asme direction
-functions in organs that secrete fluids
-inhibits luminal NKCC in the thick acending limb of loop hele
-binding NKCC causes NA,K,CL loss in urine
Describe the ENaC, what blocks it and the other drug that commons blocks it
-epithelial sodium channel
-apical membrane heterotrimeric ion channek, selectively permeable to na+
-causes resporbtion of Na+ at collecting ducts in neprons
-blocked by high affinity diuretic amiloride
-thiazide also commonly used as targets NACL costransporter that resorbs NACL from tubular fluid
-used as a anti hypertensive
Whst is a heterotrimeric ion channel
2 sets of 3 proteins
where are found in calsium voltage gated ion channels
membrane excitable cells (muscle, glial and neurons cells)
How can calcium voltage gates ions be inhibited
Amlodipine is an angioselective Calcium channel blocker
Inhibits contractions of cardiac muscles and vascular smooth muscles cells
Amlodipine inhibits Ca ion influx, which a GREATER effect in vascular smooth muscles cells
Causes vasodilation and reduction in peripheral vascular resistance - lowering BP
Also prevent excessive constriction is coronaries
Describe sodium voltage-gated channels and what blocks them
-conducts NA through plasma membrane
-has 3 states, open, closed, inactive
-lidocaine blocks transmission of the action potential
-also blocks signaling in the heart reducing arrythmia
What voltage gated channels regular insulin in the pancreas and how+ what drugs can be used
Potassium
-increase glucose = blocked ATP dependant K channels
-repetetice firing action potentials increase influx CA+ to trigger insulin secretion
-Repaglinide, nateglinide and sulfonylureal lower blood glucose levels by blocking K+ channels to stimulate insulin secretion - used to treat type 2 diabters
Describe GAB -A receptors and what can increase permeability of the channel to CL
-inhibitory
-post synaptic, opens CL- channels to induce hyperpolarisation
-Barbituates increase permeability of channel to cl
describe NAK ATPase pump
-Pumps Na out and K into cells, against their concentration gradients.
-This pumping is active (energy comes from ATP).
It has antiporter-like activity (moves both molecules against their concentration gradients.
-Pump 3 Na ions out for every 2 K ions in and creates a electrochemical gradient between a cell and its exterior.
-the reverse process (unlike the forward) is spontaneous.
