biochem and genetics incorrects

Question 1

if DNA needs to be TRANSCRIBED, what method are you using?

Answer 1

Northern blot

Question 2

mutations that result in loss of 2-3BPG cause hemoglobin to resemble what?

Answer 2

Fetal hemoglobin (binds with high affinity)

Question 3

metabolism 1g of protein, carbs and fat each produces how much energy?

Answer 3

protein and carbs = 4 cal each
fat = 9 cal

Question 4

alkapTonuria (black urine, arthritis) results from failed conversion of?

Answer 4

Tyrosine to fumarate. Homgencitic oxidase dysfucntional. HGA builds up

Question 5

how is UV light damage repaired?

Answer 5

Nicking of the damaged strand on both sides of pyridimine dimer

Question 6

Lesch Nyan syndrome (lip biting (self mutilation) dystonia, uric acid in urine) results in buildup of what molecule?

Answer 6

PRPP

(HGPRT activity reduced)

Question 7

why is repeated deoxythymidine residues likely to bind to mature MRNA?

Answer 7

due to presence of polyAtail

Question 8

a 17 year old girl with fatal aortic dissection and ovaries composed of connective tissue is also likely to have what?

Answer 8

renal fusion (turners syndrome)

Question 9

vomiting from brestfeeds, cardiomegaly, hepatomegaly and decreased erythrocyte transketolase activity in an infant may all point to?

Answer 9

thiamine deficiency (beri beri)
- defective pyruvate dehydrogenase activity

Question 10

karyotype/ chromosomes for a complete mole?

partial mole?

Answer 10

complete = empty ovum fetilised and duplication of sperm DNA = 46XX most common

Partial mole has fetal parts and = 69XXX for example. It is 2 sperm and 1 egg

Question 11

pyruvate conversion into glucose is first prompted by what enzyme?

Answer 11

acetyl coa
also inhibits glycolysis via inhibiting pyrivate dehydrogenase

Question 12

insulin acts on tyrosine kinase to promote protein synthesis via activity on which enzyme?

Answer 12

protein phosphatase (it activates glycogen synthase)

Question 13

decreased activity of what enzyme can be linked to cholesterol stone formation?

Answer 13

cholesterol-7 alpha hydroxylase (fibrate medications eg fenofibrate gemfibrozil inhibit this and favour cholesterol stone formation)

Question 14

which cell in body can carry out glycoslysis and yield pyruvate but no net ATP?

Answer 14

erythrocytes

Question 15

which sybstance is metabolised fastest in glycolytic pathway and why?

Answer 15

fructose 1 phosphate -> bypasses PFK-1

Question 16

ehlers danlos syndrome is due to abnormal what?

Answer 16

collagen

• impaired n terminal propeptide removal in collagen (procollagen peptidase deficiency)

condition causes easy bruising and hyperextendible skin

Question 17

PTH effects on 1,25 vitamin D levels

Answer 17

increases

Question 18

increased PRPP activity most likely causes?

NSAIDS used for treatment inhibit which cell line?

Answer 18

joint disease -gout - due to increased production and degradation of purines

neutrophils

Question 19

DNA polymerase 3 vs polymerase 1 activity

Answer 19

check phone/book

Question 20

Key signs of HCM include left sternal sided murmur and dyspnea. what is the mode of inheritance for this?

Answer 20

Autosomal dominant

Question 21

Hartnups disease which causes ataxia and neutral amino acids in urine can be treated with which vitamin?

Answer 21

niacin

Question 22

role of PFK enzymes and fructose-2,6-BP?

Answer 22

increase glycolysis
Prince frederick only works when fed.

There for gluconeogenesis will be inhibited, inhibiting things like alanine -> glucose

Question 23

flat facial profile, protruding tongue and small ears are features of what condition

Answer 23

down syndrome

Question 24

do hemoglobin molecules release h+ or Cl- as they become saturated?

Answer 24

H+

Question 25

Sorbitol is typically metabolised to ?

Answer 25

fructose - review this pathway

Question 26

integrin binds to what in the ECM?

Answer 26

fibronectin!!! collagen laminin

Question 27

cortisol effect on epinephrine synthesis?

Answer 27

decreases conversion of norepineprine to epinephrine via inhibition of PHENYLETHANOLAMINE -N -METHYLTRANSFERASE (PNMT)

Question 28

KRAS is active when bound to which molecule?

Answer 28

GTP

Question 29

tay sachs disease results in accumulation of?

Answer 29

GM2 ganglioside

Question 30

sideroblastic anemia is caused by defects in ezyme that catalyses what?

Answer 30

glycine + succinyl coA joining

Question 31

large anterior fontanelle, umbilical hernia, macroglossia in the presence of a floppy baby (hypotonia) is concerning for what?

Answer 31

congenital hypothyroidism

Question 32

imparied transport of ornithine can be treated by?

Answer 32

protein restriction

Question 33

hardy weinberg calculation example

Question 34

renal cell carcinoma is due to mutation of which gene?

Answer 34

VHL

Question 35

methylation of MGMT reduces tumour cells ability to?

Answer 35

repair DNA damage

Question 36

how does CO bind to Heme

Answer 36

REVERSIBLY! (NON-COMPETITIVE0

Question 37

glycerol kinase is used in ?

Answer 37

gluconeogenesis

Question 38

in essential fructokinase, patients are able to metabolise glucose through the compensatory action of?

Answer 38

hexokinase

Question 39

which hormones are DNA binding?

Answer 39

steroid receptors - cortisol aldosterone progesterone fat soulble vitmain receptors - Vitamin D

Question 40

the greenish colour of wounds is caused by?

Answer 40

heme oxygenase -> converts heme to biliverdin

Question 41

oxaloaceteate to phsphoneylpyruvate is a reaction seen in?

Answer 41

gluconeogenesis

Question 42

matuity onset diabetes of the young is due to mutations in?

Answer 42

Glucokinase - modulates pancreatic beta cell function

Question 43

RNA made of bases dihydrouridine, pseudouridine, ribothymidine is most likely to have what at its -3 end?

Answer 43

CCA reference is to TRNA CCA tail is amino acid binding site

Question 44

why are SNRAs involved in removal of introns from RNA transcripts?

Answer 44

form spliceosome

Question 45

homocystinuria (ectopic lens, marfanoid body habitus) can be treated with?

Answer 45

pyridoxine

Question 46

heme synthesis cant occur in erythrocytes due to lack of?

Answer 46

mitochondria

Question 47

acidosis causes renal metabolism of what amino acid? to maintain acid excetion

Answer 47

glutamine

Question 48

virilization and male-pattern baldness can occur as a result of a mutation in which cellular organelle?

Answer 48

smooth ER (synthesises steroids/sex steroids)

Question 49

mushroom toxins inhibit rna polymerase 2 and therefore halt synthesis of?

Answer 49

MRNA

Question 50

rate of glycogenolysis increases during skeletal muscle contraction due to presence of?

Answer 50

calcium