Biochemistry

Question 1

Xanthurenic aciduria is seen in deficiency of

Answer 1

Vitamin B6 (pyridoxal phosphate)

Question 2

What is the use of Vit B6 in Tryptophan metabolism?

Answer 2

Coenzyme required to convert 3-OH kynurenine to 3-OH anthranilic acid by kynureninase enzyme

Question 3

Type 1 DM is a ___ insulin state

Answer 3

low

Question 4

How is there DKA in Type 1 DM?

Answer 4

Low insulin —> increased fatty acid conversion to acetyl coA which inturn increases ketone in body

Question 5

Rothera test for ketone bodies

Answer 5

1. 5 ml of urine + solid ammonium sulfate
2. few drops of sodium nitroprusside (freshly prep)
3. 2 ml of liquor ammonia along side of test tube

Question 6

Seliwanoff’s test

Answer 6

To distinguish glucose and fructose
Reagent: Resorcinol in HCL
3 ml reagent + 0.5 ml urine- heat for 30 secs till boiling point
Red indicates fructose

Question 7

Benedict’s test

Answer 7

Benedicts reagent contains sodium carbonate, sodium citrate, copper sulfate

To find reducing sugars (glucose, fructose, lactose) in urine

Question 8

Fouchet’s test

Answer 8

to determine bile pigments in urine
urine heated with barium sulfate which adsorbs bile pigments
Ferric chloride added which oxidises adsorbed bilirbin to biliverdin which produces green color

Question 9

Steps of Karyotyping

Answer 9

1. Collect cells by peripheral vein using Heparin syringe
2. Culture in Phytohemagglutinin
3. Incubate at 37 C for 3 days
4. Harvest with Colchicine
5. Routine staining with Giemsa

Question 10

Common techniques of chromosome staining

Answer 10

1. Q banding: fluorescence staining with Quinacrine mustard
2. G banding: Giemsa staining after partial denaturation of chromatin
3. R banding: Reverse Giemsa staining
4. C banding: staining of heterochromatin with silver salts
5. T banding: staining the telomeres of chromosomes

Question 11

Barth syndrome defect

Answer 11

Mitochondrial dysfunction d/t decreased cardiolipin or alteration in its metabolism

Question 12

Clinical features of Barth syndrome

Answer 12

1. Weakened and enlarged heart- dilated cardiomyopathy
2. weakened skeletal muscles- skeletal myopathy
3. Recurrent infections d/t small no of white blood cells (neutropenia)
4. Short stature

Question 13

Barth syndrome is also called as

Answer 13

cardioskeletal myopathy

Question 14

Cardiolipin, aka _______ is only found in ______ where its function is to?

Answer 14

Diphosphatidyl glycerol
mitochondria
optimal function of various enzymes of mitochondria
Maintenance of structure of mitochondrial membrane

Question 15

Cephalin, aka ______, is found in cell membrane of _____

Answer 15

phosphotidylethanolamine
nervous tissue esp brain

Question 16

Defect in synthesis of ____ leads to Resp distress syndrome aka _____

Answer 16

Dipalmitoyl lecithin
Hyaline membrane disease

Question 17

Oxidised lysolecithin is associated with

Answer 17

atherosclerosis