Download MBBS UHS Lahore 1st Year Biochemistry I SEQ Question Paper

Download MBBS (Bachelor of Medicine and Bachelor of Surgery) UHS Lahore (University of Health Sciences Lahore) 1st Year Biochemistry I SEQ Previous Year Question Paper






MBBS FIRST PROFESSIONAL (PART-I)
MODEL PAPER FOR ANNUAL 2009

Biochemistry

(Short Essay Questions)

Max. Marks 32.5 Time Allowed 2 hours


1. a) What are the intracellular events following the activation of Gq protein?

2

b) Define osmotic pressure. What is the importance of osmotic pressure exerted



by plasma proteins?

2



2. a) A young lady presents to the clinic with complaints of alternating diarrhea and



constipation. She complains of abdominal discomfort and bloating that is



relieved with her bowel movement. She states that her episodes are worse in



times of stress. She denies any blood in her diarrheal stools. Her physical



examination is all within normal range. She has been prescribed a cellulose



containing dietary supplement, which her doctor says will increase the bulk of



her stool. She was diagnosed as a case of irritable bowl syndrome:



i) What is the biochemical mechanism of this dietary supplement's effect on



the intestines?

1

ii) What is the structure of cellulose?

0.5

iii) What is hemicellulose?

0.5

b) What do you understand by omega-3 fatty acids? What are the principal



biologic functions of prostacyclin and leukotriene B4?

2



3. a) What is the role of amino acid side chain (R group) in protein folding? Briefly



describe the relationship of protein structure to its function. Give at least one



example.

2

b) What are different types of immunoglobulins? Give clinical significance of IgG



and IgE.

1,1



4. a) Define nucleosides and nucleotides. Write down important functions of



nucleotides in human body.

2

b) Write down the role of Selenium as an antioxidant.

2



5. a) How can you differentiate competitive inhibition from the non-competitive



inhibition of enzyme activity?

2

b) Enumerate two clinically important enzyme inhibitors along with examples of



enzymes inhibited by them.

2



6. a) What is the mechanism of action of retinol in extraoccular tissue?

2

b) A woman who suffers from chronic peptic ulcer undergoes gastrectomy. After



some years she starts suffering from lethargy, tiredness and `pins and needles'



sensation in her lower limbs. The doctor on examination finds her to be



anaemic and diagnoses PERIPHERAL NEUROPATHY . Her blood test reveals low



Hb, 8.1 g/dl (normal 12-16 g/dl). Peripheral smear shows macrocytosis. The



serum B12 level is 8ng/dl (normal 10-70 ng/dl):



i) Which vitamin is likely to be deficient and why?

0.5

ii) Write down two reactions in the body in which this vitamin is required as



coenzyme.

0.5

iii) What is folate trap hypothesis?

1

iv) What is the biochemical defect underlying neuropathy?

0.5



7. a) Define the terms: Body Mass Index (BMI), Basal Metabolic Rate (BMR), Waist



to Hip Ratio (WHR), Resting Metabolic Rate (RMR), Thermogenic Effect of



Food.

2.5

b) What is glycemic index of food?

1.5



8.

What are thalassemias? Describe various types of alpha thalassemias?

1,3




This post was last modified on 30 November 2021