You are a biochemistry expert helping 1st year MBBS students. Answer the following questions from a Narayana Medical College 2nd Internal Assessment Exam in Biochemistry. Provide detailed, exam-ready answers with all key points, diagrams described in text where relevant. **QUESTION 1 (Essay - 10 marks, 3+2+4+1):** A 22 yr old female admitted in BURNS ward with 70% burns. Her blood investigations revealed abnormal electrolytes and Urea levels. a. What is normal Blood Urea, Serum Sodium and Potassium levels? (3 marks) b. Why Urea is elevated in burns? (2 marks) c. Outline the Urea cycle by a diagram and Add a note on its regulation. (4 marks) d. Add a note on BUN. (1 mark) **QUESTION 2 (Short Note - 5 marks, 1+1+2+1):** A 50 yr old Known Alcoholic Male patient came with complaints of severe pain in right big toe and right ankle. Swollen big toe, redness over the joint and restricted movements. Uric acid levels increased. a. What is the probable diagnosis? Interpret the case. (1 mark) b. What is normal Serum Uric acid level? (1 mark) c. What are the causes of the above disorder? (2 marks) d. What is the treatment of choice of this disorder? (1 mark) **QUESTION 3 (Short Note - 5 marks, 1+1+1+2):** A 7 yr old Male child: frequent febrile episodes, bone pain and Jaundice. Peripheral smear shows crescent shaped RBC. Lab: Serum Total bilirubin - 5 mg/dl, Serum Direct bilirubin - 0.5 mg/dl, Serum Indirect bilirubin - 4.5mg/dl, Serum Total Protein - 6.2 gm/dl, Serum Albumin - 3.5 gm/dl, ALT - 30 IU/L, AST - 26 IU/L, ALP - 120 IU/L, Urine Bile pigments and Bile salts – Negative, Urine Urobilinogen – Positive. a. What is your Probable Diagnosis? b. What is the cause of this condition and biochemical defect? c. What is the definitive diagnosis? d. Outline the Formation and Fate of Bilirubin **QUESTION 4 (Short Note - 5 marks, 1+1+3):** A 14 yr old girl: tingling sensation in hands/feet, carpopedal spasm. Trousseau's sign and Chvostek's sign positive. Reduced serum calcium. a. What is normal Serum Calcium level? (1 mark) b. What is the significance of Ionized Calcium? (1 mark) c. Source, daily requirement of Calcium and role of vitamin D in Calcium homeostasis (3 marks) **QUESTION 5 (Short Note - 5 marks, 1+1+3):** A mother sought medical help: diapers stained black, urine becomes dark on exposure, Benedict's test positive, Ferric chloride test showed purple black colour. a. What is your probable diagnosis and the defect in this disorder? b. What do you mean by OCHRONOSIS? c. Outline metabolism of Tyrosine and the products derived from it Please use the medical library database to look up authoritative answers. Search for: - Urea cycle, BUN, burns urea - Gout, uric acid, allopurinol - Sickle cell anemia, bilirubin metabolism - Hypocalcemia, calcium homeostasis, vitamin D - Alkaptonuria, ochronosis, tyrosine metabolism Use these SQL queries on the medical library: ```sql SELECT book_title, section_heading, '/textbooks/' || block_file_path AS file_path, line_start, line_end, snippet(paragraphs_fts, 0, '>>>', '<<<', '...', 30) as snippet FROM paragraphs_fts WHERE paragraphs_fts MATCH 'urea cycle regulation' ORDER BY rank LIMIT 5 ``` Provide comprehensive exam-ready answers covering all sub-parts.

You are a biochemistry expert helping 1st year MBBS students. Answer the following questions from a Narayana Medical College 2nd Internal Assessment Exam in Biochemistry. Provide detailed, exam-ready answers. **QUESTION 6 (Short Note - 5 marks):** Salvage pathways of Purine nucleotide synthesis and its Significance. Add a note on disorders associated with it. **QUESTION 7 (Short Note - 5 marks):** Sources, Daily requirement and Biochemical functions of Pyridoxine (B6). **QUESTION 8 (Short Note - 5 marks):** Transmethylation reactions and its significance. **QUESTION 9 (Short Note - 5 marks):** What are the Different forms of Vitamin A and their Biochemical role in our body? **QUESTION 10 (Short Note - 5 marks):** Define Porphyrias. Classify the different types of Porphyria. Give an account of the Acute intermittent porphyria. **QUESTION 11 (Short Note - 5 marks):** Biochemical functions of Copper and Zinc and its associated disorders. **QUESTION 12 (Short Note - 5 marks):** Sources, Daily requirement, absorption, transport, storage and deficiency manifestations of IRON. **QUESTION 13 (Reasoning - 5 marks):** Metabolic link between Folic acid and Vitamin B12 and its significance. **QUESTION 14 (Reasoning - 5 marks):** Pellagra like symptoms in Hartnup's disease - Justify. **QUESTION 15 (Reasoning - 5 marks):** Von Gierke's disease – What is the enzyme deficient and What is the reason for hyperuricemia in this disorder. **QUESTION 16 (Reasoning - 5 marks):** Poor wound healing in Scurvy - Justify. **QUESTION 17 (Reasoning - 5 marks):** Name two Anticancer agents and their mechanism of action. Please use the medical library database to look up authoritative answers. Use these SQL queries: ```sql SELECT book_title, section_heading, '/textbooks/' || block_file_path AS file_path, line_start, line_end, snippet(paragraphs_fts, 0, '>>>', '<<<', '...', 30) as snippet FROM paragraphs_fts WHERE paragraphs_fts MATCH 'purine salvage pathway HGPRT' ORDER BY rank LIMIT 5 ``` Also search for: pyridoxine B6, transmethylation SAM, vitamin A retinol, porphyria acute intermittent, copper ceruloplasmin Wilson, iron absorption ferritin, folic acid B12 methyl trap, Hartnup tryptophan, Von Gierke glucose-6-phosphatase, scurvy collagen, anticancer methotrexate 5-fluorouracil. Provide comprehensive exam-ready answers for each question.