Distribution And Metabolism Flashcards
How are drug molecules enterin target cells
Passive diffusion
Facilitated diffusion
Active transport
Endocytosis
What is passive diffusion
Drug has to get into membrane - has to be sufficiently lipphylic so that the drug will interact ell with the hydrophobic centre of the membrane - has to be hydrophobic enough to come out the other side
Drug touches side of membrane, cell membrane forms walls around it and encapsulated it and brings it into the cell where it bursts
What happens during facilitated iffusion
Channels in the cell made of protein
Protein goes across membrane
Drug go through the channel
Works for polar and non-polar molecules
Does active transport use ATP
Hes
How does active transport work
Transporter protein binds ATP molecule onto the cytoplasmic side of the membrane and it idolised atp into ADP and in inorganic phosphate
This generates energy to pump drug molecules through the Chanel
The ADP and inorganic phosphate move off transporter and they get recycled back into atp in the mitochondria
What is endocytosis made up of
Phagocytosis
Pinocytosis
Receptor mediated endocytosis
What is phagocytosis
Nanoparticle goes towards surface of cell and touches it
Cell membrane starts to move up the sides of the particle it it fuses over the top
Nano-particle is now in a small vesicle which passes through the membrane
Once inside the membrane the vesicle burst
What is pinocytosis?
Membrane grows around small body of water where drug molecules are
The membrane fuses over the fluid
Vesicle is internalised and separated from the membrane and burst
There is no specific receptor to make this process happen
What is receptor mediated endocytosis
Protein which bind things
Receptor on surface wall - drug molecules bind to receptors into a pit on a cell surface
The pit depends as more drugs bind an membrane closes over the pit
This creates a vesicle
The vesicle bursts and releases the drug
What happens if a drug cannnot be excreted
It gets metabolised into a more polar molecule - makes it easier to be excreted in urine
Becomes less toxic
Where does phase 1 metabolism occur
Liver
What happens during phase 1 metabolism
Oxidation
Reduction
Hydrolysis
What happens in phase 2 metabolism
Conjugation with endogenous polar molecules to make the drug more polar and soluble
Where does phase 2 metabolism occur
Liver
Where does phase 3 metabolism occur
Liver or kidney
