Pharmacodynamics (my Cards) Flashcards
What is the definition of pharmacodynamics? (3)
1) ‘How the drug works’
2) The study of the drug mechanisms that produce biochemical or physiological changes in the body.
3) The interaction at the cellular level between a drug and cellular components.
What is MRNA?
MRNA is a molecule responsible for transfers g genetic information from DNA found in the nucleus of the cell to ribosomes floating in the cell cytoplasm.
What are amino acids?
Molecules that combine to form proteins .
What is a chain of amino acids called?
Polypeptide
Describe an amino acid group (2)
1) An amine group at one end (this is called the N terminal)
2) A carboxyl group on the other end (this is called the C terminal)
What causes a protein to change shape? (2)
1) PH
2) temperature
What is an Ion?
An Ion is an atom or molecule with electrical change due to the loss of gain of one or more electrons.
What is a Zwitterions? (2)
1) A Zwitterions is an ion possessing both negative and positive electrical charges.
2) Zwitterions are mostly electorally neutral.
What is a proton donor?
(Give an example)
Hydrogen ions (+ve) can donate to amine end
When measuring PH, what are you measuring?
Hydrogen ions because hydrogen ions are acid.
What does the lipid cell membrane do?
Provide a barrier against the transport of hydrophilic molecules into or out of the cell
A) what is hydrophobic?
B) what is hydrophilic?
A) (hydrophobic) water-fearing. Naturally repel water
B) (hydrophilic) water loving. Has an affinity to water
Drugs work by 4 main mechanisms, what are these?
RICE
1) Receptors
2) Ion channels
3) Carrier molecules
4) Enzymes
What are Receptors?
Receptors are protein molecules that are normally activated by transmitters or hormones
What are the 4 main types of receptors?
1) linand gated channel receptors
2) G protein coupled receptors
3) Kinase linked receptors
4) Nuclear receptors
What are the characteristics of a linand gated channel receptor? (5)
1) Agonist
2) response time of milliseconds
3) Inotropic (increasing or decreasing force)
4) Excitable tissue (nerve/cardiac)
5) examples (SHT3, ACh, GABAa)
What are the characteristics of a G protein coupled receptor? (4)
1) Metabotropic (action is mediated by metabolic functions)
2) linked to physiological response by second messengers
3) form a family of receptors with 7 membranes spanning helices
4) response time of seconds
7TMD = 7 transmembrane domain
What are the characteristics of nuclear receptors? (4)
1) present in the cell nucleus
2) Regulates transcription and protein synthesis
3) Bind to DNA and switches genes on and off
4) Response time of hours
(Example = steroids)
What are the characteristics of Kinase linked receptors? (4)
1) Surface receptors (extra cellular)
2) Enzyme amplifier
3) Possess intrinsic tyrosine kinase activity
4) Response time of hours
(Example - insulin)
(RTK = receptor tyrosine kinases)
What are the main characteristics of ion channels? (6)
1) can be closed, open or inactive
2) drugs either block or modulate channels (the binding of a drug to a site on the associated receptor can either increase or decrease ion channel opening
3) There are 4 main types of ion channels
4) Important for systems that require a rapid response (NS renal CVS)
5) Ions need the help of proteins to cross cell membrane (such as ion channels)
6) Don’t bind but form a channel through the membrane
What are the 4 main types of ion channels?
1) Ligand gated (activated by the binding of ligands to a specific receptor, which forms part of the ion channel (extra cellular)
2) as above but intracellular
3) Voltage gated (activated following a change in voltage)
4) Mechanically gated (weight or force of molecule hitting it open)
What are the main characteristics of carrier molecules? (5)
1) Transport a substrate across a cell membrane
2) Carrier molecules can be ion, glucose or amino acids
3) Carry a specific molecule/shape
4) Drugs can act to modulate the function of carrier molecules directly or indirectly
5) Some drugs target these carriers and block transport (common by inhibiting enzyme ATP, that provide energy to drive them)
Drugs can act to modulate the function of carrier molecules directly or indirectly
Explain….,
Direct - Bind completely to the carrier preventing the binding of ligands
Indirect - Bind to a separate site on the carrier and alter the 3D shape, preventing the binding of ligands.
Allosteric = change shape
What are the two types of carrier molecules?
1) Energy dependent (can work across a concentrated gradient)
-requires energy, usually ATP (adenosine triphosphate)
2) Energy independent (can only work down a concentrated gradient)
- Transporters (single molecule in one direction)
- Symporters (2 molecules in the same direction)
- Antiporter (2 molecules in opposite directions)