FunMedEOYS3 Flashcards
(47 cards)
what property do intracellular receptor proteins have? [1]
give 4 examples [4]
how do they cause change in body? [1]
what property do intracellular receptor proteins have? [1] hydrophobic
give 4 examples [4]
steroid H
thyroid H
vitamin D
retinoids
how do they cause change in body? [1]
bind to nuclear receptor
change gene transcription
define drug
a) tachyphylaxis [1]
b) tolerance [1]
define drug
a) tachyphylaxis [1] acute tolerance from rapid and repeated admin of drugs in short intervals
b) tolerance [1] chronic longer term admin can reduce drug effect (e.g. alchohol)
give 3 mechanisms that tachyphylaxis can occur [3]
mechanisms for tolerance or tachyphylaxis:
- receptor desensitized or loss of receptors
- receptor internalisation (degraded in lysosome)
- increased metaboloic degradation of drug
where do you find glycoproteins? [1]
where do you find proteoglycans? [1]
▪Glycoproteins:
Molecules made up of proteins and carbohydrates e.g., laminin and fibronectin
Found on the surface of the lipid bilayer of cell membranes (cell surface)
▪Proteoglycans:
Molecules made up of a core protein attached to glycosaminoglycans (GAGs)
Found in connective tissues
which molecule causes receptor modulation? [1]
B arrestin
which method of administration of drugs goes straight into the CSF? [1]
intrathecal
which family of enzymes undergoes oxidation reaction in biotransformation? [1]
cytochrome P450 enzymes
what happens to drugs if reabsorbed back into bile?
phase 1 drug? [1]
phase 2 drug? [1]
what happens to drugs if reabsorbed back into bile?
i) phase 1 drug: reabsorbed from GI system and goes back to liver 4 further met.
ii) phase 2 drug: exits via defecation
what is clearance?
how calculate?
clearance: rate of elimination in relation to the drug concentration
clearance = rate of elimination (through urine) / concentration remaining (in blood plasma)
how do u work out 1/2 life of a drug?
how many types of muscarinic receptors are there? which ones are inhib/ excitatory? - what are second messengers for inhibit / excitatory?
5 types:
- M1 = excitatory: 2nd messenger = IP3 & DAG
- M2 = inhibitory: 2nd messenger = cAMP
- M3 = excitatory: 2nd messenger = IP3 & DAG
- M4 and M5 in CNS (dont need to know)
what type of receptors are adrenergic receptors? what does this mean with regards to their action?
GCPR - can have excitatory or inhibitory response (depending on 2nd messenger system)
Q
what are NANC neurons?
where found?
what are the NTs used ? (probs dont need to know exact)
- NANC = non-adrenergic non cholinergic neurons (NTs aren’t adreneric or cholinergic class)
- location: peripheral tissues - smooth muscle in GI, airways and reproductive tracts
- NTs: nitric oxide, ATP, 5HTP, neuropeptide Y
autonomic NS that doesnt use Ach, adrenaline or noradrenaline !!
what variants of adrenoreceptors are there? which are pre / post synaptic? excitatory or inhbitor?
alpha:
- alpha 1: postsynaptic excitatory
- alpha 2: presynaptic. inhbits further release of noradrenaline
beta:
- beta 1: postsynaptic excitatory
- beta 2: postsynaptic excitatory
- beta 3: postsynaptic excitatory
what are the components of ECM? [4] (MESS)
▪ Collagens: Major protein of the body (25%) and The ECM
▪Elastin: Provides elasticity and resilience to tissues such as the arteries, lungs, tendons, skin, and ligaments
▪Glycoproteins:
Molecules made up of proteins and carbohydrates e.g., laminin and fibronectin
Found on the surface of the lipid bilayer of cell membranes (cell surface)
▪Proteoglycans:
Molecules made up of a core protein attached to glycosaminoglycans (GAGs)
Found in connective tissues
describe the structure of collagen [3]
Triple helical structure formed by 3 peptide chains
: ▪every 3rd amino acid is glycine
▪Gly-X-Y (proline-hydroxyproline)
explain difference between fibrillar and non-fibrillar collagen
- *non-fibrillar collagen:**
- forms microfibrils or mesh-like structures.
- therefore is used for anchorage of cells and filtration
- major structural components of basement membranes - relatively thin layers of ECM
- *fibrillar collagen:**
- forms well-organised banded fibrils, with provide high tensile strength. therefore is used for major components in tendons, ligaments, skin etc
describe pathophysiology of osteogenesis impefecta [2]
what are the two types ofOsteogenesis imperfecta? [2]
brittle bone disorder
in type 1 collagen: single base mutations cause Gly to convert to bulky amino acid. this prevents the corrected triple helix formation of collagen into fibrils. therefore is loose triple helix
- *Type 1:**
a) autosomal dominant
b) most common - 50% of cases
c) mildest type
d) COL1A1 & A2 genes are mutated on chr. 17 and 7 respectively. causes an amino acid change - looser collagen chain and looser triple helix. - *Type 2:**
- more severe - babies born with so many broken bones they die.
- usually new mutation
- dominant if affected individuals survive
what is structure of elastin like?
- rich in glycine and proline - like collagen, but has more valine which interacts with hydrophobic domains, therefore makes it elastic.
- elastin fibres are normally covered by the glycoprotein fibrillin.
- can stretch in 2D.
- when in relaxed state, fibres are jumbled. when stretch - stretches out and gives flex.
what is Marfan syndrome?
-rare genetic disease (1/10000)
- fibrillin protein is mutated and usually absent:
characteristics:
tall stature, long arms and legs, arachnodactyly (spider fingers), loose joints, floppy cardiac valves, eye problems, aortic aneurysms
what is Marfan syndrome?
-rare genetic disease (1/10000)
- fibrillin protein is mutated and usually absent:
characteristics:
tall stature, long arms and legs, arachnodactyly (spider fingers), loose joints, floppy cardiac valves, eye problems, aortic aneurysms
what are laminin and fibronectin and what are their roles?
both glycoproteins
1. laminin:
- cell adhesion to the ECM.
- cell migration
- cytoskeleton organisation
2. fibronectin
cell adhesion to the ECM.
cell migration
cell shape
cell differentiation
cytoskeleton organisation
describe structure of proteoglycan [2]
what gives proteoglycans their negative charge? [1]
- Proteoglycans form large aggregates within tissues made up of lots of side chains of negatively charged GAGs
- *- peptide chain with covalently bound sugars. - mainly made of GAGs (glycosaminoglycans)**
- 95% carb, 5% protein
- GAG side chains have sulphate group - gives a negative charge. this attracts water and so water moves into ECM
- gel forming components of ECM.
structure of antibody?
- antigen binding site is combination of light chain and heavy chain
- Fragment antigen binding is at the top
- Fc is at the bottom: determines role of antibody (if IgE / IgM etc)
