MMF mock Flashcards
which aa are helix formers
alanine and leucine
which aa are helix breakers
proline and glycine
what does mitotic non disjunction result in
mosaicism with two or more cell lines
what does non disjunction in meiosis result in
aneuploidy (abnormal n.o chromosomes)
trisomy disorders
down syndrome
patau’s syndrome
Edwards’ syndrome
monosomy disorder
turner syndrome
what is the difference between mismatch repair and nucleotide excision repair
nucleotide- occurs when DNA gets damaged
mismatch- occurs immediately after DNA synthesis
3 types of DNA repair mechanisms
- bas excision repair = corrects damage to bases
- nucleotide excision repair =repairs bulky lesions in DNA that alter the helix (correct pyrimidine primers)
- mismatch repair = correct replication mispairing/ insertions/ deletions
feature of X- linked dominant inheritance pattern?
Affected males cannot give trait to their sons but will give it to all their daughters
difference between Marasmus and Kwashiorkor’s
Marasmus- insufficient energy intake.
thin, bony child.
kwashiorkor’s - low protein intake.
pot belly
oedema due to insufficient protein in liver. unable to synthesise albumin. reduced oncotic pressure of plasma.
sensitivity formula
TP/ TP + FN
amount who tested positive and have it/ total amount who have it.
TP=true positive. FP=false negative.
specificity formula
TN/ TN + FP
amount who tested negative and don’t have it/ total amount who don’t have it.
TN=true neg. FP=false postive.
positive produced value and NPV formula
total positive who actually have the disease: those who have the disease/total positive
NPV
those who don’t have disease/ n.o people who got a negative result
psychosocial health inequality explanation
health is influenced more by differences in income rather than actual income
Spermatozoa, erythrocytes and other motile cells don’t contain what type of cell adherence system?
Gap junctions
which examination technique is used for analysing tissues during surgery (inoperative consultation)
frozen section
- quick to make
club cells role
Protect bronchioles and act as stem cells for respiratory epithelium
keratin role
Prevents water loss and protects against abrasion
goblet cells role
Secrete mucus, moistens and lubricates respiratory tract
Hashimotos plasma examination
hypothyroidism
low T3, low T4, high TSH
body produces auto antibodies against enzymes that make T3/T4.
receptor Gas subunit targets which protein?
adenylyl cyclase to create cAMP
cAMP target effector protein = protein kinase A (PKA)
feature of GPCRs
- 7 transmembrane receptor proteins
- |igand binding domain is extracellular
- the binding region of the G-protein involves one of the intracellular loops and the C-terminal chain
- N terminal = extracellular. C terminal = intracellular
which is the main channel contributing to resting membrane potential
K+ channels
open = K+ leaves cell. down conc grad.
role of beta blockers
reduce blood pressure BUT
inhibit B1 receptors> less cAMP production> less PKA stimulation> less Calcium enter cell > reduced force of heart contraction. negative inotrophy.
enzyme missing in fructose intolerance
aldolase
give examples of DNA damage
mismatches deamination single strand breaks double strand breaks inter-strand crosslink bulk adducts
what type of GPCR is salbutamol
B2 adrenoreceptor agonist
what is alport syndrome
X-linked condition
defective collagen type 4 (basement membrane)
kidney can’t filter blood and protein out from urine.
- deafness
- poor eyesight
- proteinuria
- hematuria
collagen synthesis process
1)Signal peptide (at the N terminus) is cleaved, by proteolytic cleavage, by signal peptidase.
2)Preprocollagen becomes procollagen as a result.
3)Hydroxylation of proline and lysine residues occurs
to increase the number of hydrogen bonds between the triple helix of procollagen to stabilise it.
4)Glycosylation
Packed into a transfer
5)vesicle to be taken to golgi from ER lumen.
6) Outside the cell the N and C terminal peptides are removed so a collagen fibril can be formed. Fibrils are covalently crosslinked to form collagen fibres.
ectopic pregnancy can lead to
internal bleeding leading to hypovolemic shock
function of zone pellucida
prevent polyspermy of fertilised egg cell (zygote). Prevents sperm entry.
what type of agonist causes bronchodilation and how does this work?
Beta 2 adrenergic agonist binds to beta adrenergic receptors causing conformational change.
GTP displaces GDP which activates the G protein coupled with adenylyl cyclase.
ATP converted into cAMP. high levels of cAMP > smooth muscle relaxation
why are B2 agonists given by inhalation
reduced adverse side effects. effect mainly localised within the lungs. limited absorption into the systemic circulation.
e.g. could activate B1 receptors in heart causing tachycardia
how does the whooping cough toxin prevent changes in intracellular cAMP levels?
- covalently modifies Qi units on G protein receptors
> prevents G proteins from interacting with GPCR.
> stops GDP and GTP exchange. no signal transduction. - Gi subunits remain inactive so are unable to inhibit adenylyl cyclase activity > inc conc of cAMP
what do M3 receptors in lungs cause
bronchoconstriction
drug types to treat bronchoconstriction
muscarinic cholinoreceptor ANTagonists
anticholinergic drugs
> work on M3 receptor.
OR
B2 adrenergic agonist
compare heroin and buprenorphine
heroin- full agonist
buprenorphine- partial agonist.
- higher affinity. occupies receptors and limits response.
buprenorphine doesn’t give maximal response so withdrawal symptoms occur.
compare a irreversible competitive agonist to a reversible competitive agonist (on an agonist conc curve)
Reversible competitive antagonist will cause a parallel shift to the right of the agonist concentration response curve
Irreversible competitive antagonists will cause a parallel shift to the right and at higher concentrations, suppress the maximal response (Emax)
how to calculate volume of distribution (Vd)
Vd = total amount of drug in body plasma / concentration of drug at time = zero
Which component of a cell has capacitance?
Lipid bilayer
