MMF mock

Question 1

which aa are helix formers

Answer 1

alanine and leucine

Question 2

which aa are helix breakers

Answer 2

proline and glycine

Question 3

what does mitotic non disjunction result in

Answer 3

mosaicism with two or more cell lines

Question 4

what does non disjunction in meiosis result in

Answer 4

aneuploidy (abnormal n.o chromosomes)

Question 5

trisomy disorders

Answer 5

down syndrome
patau’s syndrome
Edwards’ syndrome

Question 6

monosomy disorder

Answer 6

turner syndrome

Question 7

what is the difference between mismatch repair and nucleotide excision repair

Answer 7

nucleotide- occurs when DNA gets damaged

mismatch- occurs immediately after DNA synthesis

Question 8

3 types of DNA repair mechanisms

Answer 8

• 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

Question 9

feature of X- linked dominant inheritance pattern?

Answer 9

Affected males cannot give trait to their sons but will give it to all their daughters

Question 10

difference between Marasmus and Kwashiorkor’s

Answer 10

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.

Question 11

sensitivity formula

Answer 11

TP/ TP + FN

amount who tested positive and have it/ total amount who have it.

TP=true positive. FP=false negative.

Question 12

specificity formula

Answer 12

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.

Question 13

positive produced value and NPV formula

Answer 13

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

Question 14

psychosocial health inequality explanation

Answer 14

health is influenced more by differences in income rather than actual income

Question 15

Spermatozoa, erythrocytes and other motile cells don’t contain what type of cell adherence system?

Answer 15

Gap junctions

Question 16

which examination technique is used for analysing tissues during surgery (inoperative consultation)

Answer 16

frozen section

- quick to make

Question 17

club cells role

Answer 17

Protect bronchioles and act as stem cells for respiratory epithelium

Question 18

keratin role

Answer 18

Prevents water loss and protects against abrasion

Question 19

goblet cells role

Answer 19

Secrete mucus, moistens and lubricates respiratory tract

Question 20

Hashimotos plasma examination

Answer 20

hypothyroidism

low T3, low T4, high TSH

body produces auto antibodies against enzymes that make T3/T4.

Question 21

receptor Gas subunit targets which protein?

Answer 21

adenylyl cyclase to create cAMP

cAMP target effector protein = protein kinase A (PKA)

Question 22

feature of GPCRs

Answer 22

• 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

Question 23

which is the main channel contributing to resting membrane potential

Answer 23

K+ channels

open = K+ leaves cell. down conc grad.

Question 24

role of beta blockers

Answer 24

reduce blood pressure BUT

inhibit B1 receptors> less cAMP production> less PKA stimulation> less Calcium enter cell > reduced force of heart contraction. negative inotrophy.

Question 25

enzyme missing in fructose intolerance

Answer 25

aldolase

Question 26

give examples of DNA damage

Answer 26

mismatches
deamination
single strand breaks
double strand breaks
inter-strand crosslink
bulk adducts

Question 27

what type of GPCR is salbutamol

Answer 27

B2 adrenoreceptor agonist

Question 28

what is alport syndrome

Answer 28

X-linked condition
defective collagen type 4 (basement membrane)
kidney can’t filter blood and protein out from urine.

• deafness
• poor eyesight
• proteinuria
• hematuria

Question 29

collagen synthesis process

Answer 29

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.

Question 30

ectopic pregnancy can lead to

Answer 30

internal bleeding leading to hypovolemic shock

Question 31

function of zone pellucida

Answer 31

prevent polyspermy of fertilised egg cell (zygote). Prevents sperm entry.

Question 32

what type of agonist causes bronchodilation and how does this work?

Answer 32

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

Question 33

why are B2 agonists given by inhalation

Answer 33

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

Question 34

how does the whooping cough toxin prevent changes in intracellular cAMP levels?

Answer 34

• 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

Question 35

what do M3 receptors in lungs cause

Answer 35

bronchoconstriction

Question 36

drug types to treat bronchoconstriction

Answer 36

muscarinic cholinoreceptor ANTagonists

anticholinergic drugs

> work on M3 receptor.

OR
B2 adrenergic agonist

Question 37

compare heroin and buprenorphine

Answer 37

heroin- full agonist
buprenorphine- partial agonist.
- higher affinity. occupies receptors and limits response.

buprenorphine doesn’t give maximal response so withdrawal symptoms occur.

Question 38

compare a irreversible competitive agonist to a reversible competitive agonist (on an agonist conc curve)

Answer 38

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)

Question 39

how to calculate volume of distribution (Vd)

Answer 39

Vd = total amount of drug in body plasma / concentration of drug at time = zero

Question 40

Which component of a cell has capacitance?

Answer 40

Lipid bilayer