Enzymes & Biological Oxidation
Correlation
Q: Name the Liver Specific Enzyme? (Topic: Enzymes)
A: ALT (Alanine Transaminase), AST (Aspartate Transaminase)
Q: ALT and AST belong to which class of enzymes? (Topic: Enzymes)
A: Transferase (Class 2 Enzymes)
Q: ALT, AST carry out which reaction? (Topic: Amino Acids & Proteins)
A: Transamination
Q: Name the coenzyme required for transamination? (Topic: Enzymes)
A: PLP (Pyridoxal Phosphate)
Q: PLP is derived from which vitamin? (Topic: Vitamins)
A: Vitamin B6 (Pyridoxine)
Q: Name other reactions involving PLP as coenzyme? (Topic: Vitamins)
A: Decarboxylation, Deamination, Transulfuration
Q: Name products of decarboxylation? (Topic: Amino Acids & Proteins)
A: Histamine, Serotonin, Catecholamines (Dopamine, Norepinephrine, Epinephrine), GABA
Q: Catecholamines are synthesized from which Amino Acid? (Topic: Amino Acids & Proteins)
A: Tyrosine
Correlation
Q: Name the class of enzyme involved in Hydrogen-electron transfer. (Topic: Enzymes)
A: Oxidoreductase (Class 1 Enzymes)
Q: Mention Example of enzyme belonging to Class of oxidoreductase. (Topic: Enzymes)
A: Alcohol Dehydrogenase, Lactate Dehydrogenase
Q: Mention the coenzyme for Dehydrogenase Enzymes. (Topic: Enzymes)
A: NADH
Q: NADH is derived from which vitamin? (Topic: Vitamins)
A: Vitamin B3- Niacin
Q: Deficiency of Niacin leads to? (Topic: Vitamins)
A: Pellagra- Diarrhea, Dermatitis, Dementia
Q: Name the Mineral, whose deficiency leads to dermatitis. (Topic: Minerals)
A: Zinc deficiency leads to Acrodermatitis Enteropathy
Q: Zinc is a Cofactor for which enzymes? (Topic: Enzymes)
A: Carbonic anhydrase, alcohol dehydrogenase, alkaline phosphatase, carboxypeptidase, superoxide dismutase, Lactate dehydrogenase, DNA and RNA polymerase
Correlation
Q: Name the anticancer drug which acts by mechanism of competitive inhibition? (Topic: Enzymes)
A: Methotrexate/Aminopterin acts by competitively inhibiting enzyme Dihydrofolate Reductase.
Q: Anticancer drug- Methotrexate is antagonist to which vitamin? (Topic: Vitamins)
A: Folic Acid
Q: Name the other inhibitor of folic acid. (Topic: Vitamins)
A: Sulfonamides: Structural analogues of PABA
Q: Mention mechanism of sulfonamides leading to drug induced hemolytic anemia. (Topic: Carbohydrates)
A: Sulfamethoxazole (sulfonamide antibiotic) precipitate the hemolysis- jaundice and severe anemia.
Q: Name the clinical disorder which causes drug induced hemolytic anemia with antimalarial, antipyretic or antibiotic. (Topic: Carbohydrates)
A: G6PD Deficiency anemia. (Glucose 6 Phosphate Dehydrogenase)
Q: G6PD is regulatory enzyme of which pathway? (Topic: Carbohydrates)
A: HMP Shunt
Q: Mention the metabolic significance of HMP shunt. (Topic: Carbohydrates)
A: Formation of NADPH, Provision of pentoses
Q: NADPH coenzyme is derived from which vitamin? (Topic: Enzymes)
A: Niacin Vitamin B3
Correlation
Q: Enzyme Glucokinase exhibits which type of enzyme specificity? (Topic: Enzymes)
A: Absolute Specificity
Q: Name the enzyme which catalyzes reaction opposite to Glucokinase? (Topic: Carbohydrates)
A: Glucose-6-phosphatase in Gluconeogenesis
Q: Name the Glycogen storage disorder due to deficiency of Glucose-6-phosphatase? (Topic: Carbohydrates)
A: Von-Gierke’s Disease
Q: Mention the biochemical features of Von-Gierke’s Disease. (Topic: Carbohydrates)
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- Hypoglycemia: Free glucose not released from liver
- Lactic Acidemia: Glucose not produced from lactate
- Hyperlipidemia: More lipolysis as glucose not available
- Hyperuricemia: G-6-P diverted to HMP shunt
Q: Name the condition for clinical progression of hyperuricemia to Monosodium urate crystals are deposited in the synovium and synovial fluid of the joints. (Topic: Nucleotides)
A: Gout/Gouty Arthritis
Q: Mention the normal range of serum uric acid. (Topic: Nucleotides)
A: Uric acid: 3-7 mg/dl (males); In females, slightly lower
Q: Mention the drug used in treatment of gout, which acts by competitive inhibition. (Topic: Enzymes)
A: Allopurinol- Competitive inhibitor of enzyme Xanthine oxidase
Correlation
Q: Heavy metal ions/Organophosphorus poisons acts by which mechanism? (Topic: Enzymes)
A: Irreversible Non-competitive inhibition.
Q: Mention the change in Km & Vmax value in non-competitive inhibition. (Topic: Enzymes)
A: Km unchanged; Vmax lowered
Q: Mention the mechanism of action of cyanide. (Topic: Biological oxidation)
A: Cyanide inhibits Cytochrome oxidase (Complex IV of Electron Transport Chain) by non-competitive inhibition.
Q: Which minerals act as a cofactors for Cytochrome oxidase? (Topic: Enzymes)
A: Iron & Copper
Q: Mention the role of copper in heme synthesis. (Topic: Hemoglobin)
A: As a cofactor of enzyme ALA synthase (heme synthesis), it is required for the formation of hemoglobin, myoglobin and cytochromes.
Q: Mention the genetic disease related to copper metabolism also known as hepatolenticular degeneration. (Topic: Minerals)
A: Wilson’s disease
Q: Mention the genetic defect in Wilson’s disease. (Topic: Nucleic acids)
A: Due to mutations in the gene for a copper -binding ATPase,
Q: Mention the role of mutations in PCR Polymerase chain reactions. (Topic: Recombinant DNA Technology)
A: Gene segments that contain mutations are amplified to enable diagnosis of inherited diseases such as sickle cell anemia, cystic fibrosis, beta-Thalassemia etc.
Correlation
Q: Name the competitive inhibitor which lowers cholesterol levels in Plasma? (Topic: Enzymes)
A: Lovastatin which competitively inhibits enzyme HMG CoA Reductase.
Q: Mention the change in Km & Vmax value in competitive inhibition. (Topic: Enzymes)
A: Km increases; Vmax unchanged
Q: Mention significance of Km Value. (Topic: Enzymes)
A: Measures strength of ES complex & denotes the affinity of enzyme for the substrate.
Low Km: High affinity E-S
High Km: Low affinity E-S
Q: HMG CoA Reductase is rate limiting enzyme of which pathway? (Topic: Lipids)
A: Cholesterol Biosynthesis
Q: Name the vitamin which is synthesized from cholesterol. (Topic: Lipids)
A: Vitamin D
Q: Active form of Vitamin D? (Topic: Vitamins)
A: Calcitriol (1.25 Dihydroxycholecalciferol)
Q: Name the organ where Vitamin D is synthesized? (Topic: Organ Function Test)
A: Kidney (First step in Liver, Second step in kidney)
Q: Deficiency of vitamin D leads to? (Topic: Vitamins)
A: Rickets in Children, Osteomalacia in adults
Q: Name the marker enzyme for Rickets, Osteomalacia & other bone disorders. (Topic: Enzymes)
A: Alkaline phosphatase
Q: Other than bone disorders, alkaline phosphatase is a marker enzyme for? (Topic: Organ Function Tests)
A: Obstructive jaundice (Cholestasis)
Correlation
Q: Name the Physiological uncoupler which is a hormone. (Topic: Biological Oxidation)
A: Thyroxine
Q: Thyroxine is synthesized from which Amino acid? (Topic: Amino Acids & Proteins)
A: Tyrosine
Q: Mention other products of Tyrosine. (Topic: Amino Acids & Proteins)
A: Melanin, Dopamine, Norepinephrine, Epinephrine
Q: Mention the mineral involved in Thyroxine synthesis. (Topic: Minerals)
A: Iodine
Q: Mention dietary sources of Iodine (Topic: Minerals)
A: Seafoods and plant foods grown near the sea are the best sources. Drinking water, vegetables, fruits, iodised salt.
Q: Which is an active form of Thyroid hormone T3 or T4? (Topic: Organ function Tests)
A: T4 is four times more active than T3
Q: Mention effect of thyroid hormones on BMR. (Topic: Nutrition)
A: Thyroid hormones stimulates BMR
Q: Other than BMR which are other contributors of Energy expenditure. (Topic: Nutrition)
A: SDA (Specific Dynamic action), Physical Activity
Correlation
Q: Name Proton pump complexes in ETC. (Topic: Biological Oxidation)
A: I, III, IV
Q: Name inhibitors of Complex IV in ETC. (Topic: Biological Oxidation)
A: Cyanide, Sodium Azide, CO, H2S
Q: Mention the Mechanism of Cyanide Inhibition. (Topic: Enzymes)
A: Non- Competitive (Irreversible)
Q: Mention Effect of non-competitive inhibition on Km and Vmax. (Topic: Enzymes)
A: Vmax Decreased, Km Unchanged
Q: Mention example of Non Competitive inhibition related to Glycolysis. (Topic: Enzymes)
A: Enolase Enzyme inhibited by Fluoride
Q: Mention fluoride’s Significance in blood glucose estimation. (Topic: Carbohydrates)
A: Fluoride bulb used in Glucose Estimation as fluoride inhibits glycolysis.
Q: Mention Non-Competitive inhibition example related to Kreb’s Cycle. (Topic: Carbohydrates)
A: Arsenite – µ-ketoglutarate dehydrogenase (Non-competitive)
Q: Enzyme Dehydrogenase enzymes belongs to which class of enzymes? (Topic: Enzymes)
A: Oxidoreductase
Q: Mention coenzyme for dehydrogenase enzyme. (Topic: Enzymes)
A: NADH
Q: NADH donates electron to which complex in ETC. (Topic: Biological Oxidation)
A: Complex I
Correlation
Q: What is the Effect of temperature on enzyme activity? (Topic: Enzymes)
A: Bell shaped curve
Q: What is optimum temperature for enzyme activity? When denaturation starts? (Topic: Enzymes)
A: Temperature at which maximum amount of S is converted to product. (40˚C-45˚C) Denaturation starts above 50˚C
Q: Mention agents of denaturation. (Topic: Amino Acids & Proteins)
A: Physical: Heat, Mechanical shaking, X-rays.
Chemical: Acids, alkalis, salts of heavy metals.
Q: Mention the biochemical test based on principle of denaturation by heat. (Topic: Amino Acids & Proteins)
A: Heat coagulation test.
Q: Mention the significance of heat coagulation test. (Topic: Amino Acids & Proteins)
A: To detect proteinuria.
Q: Proteinuria is useful for measurement of which kidney function? (Topic: Organ Function Test)
A: Measuring the proteinuria reflects glomerular permeability. It is used to assess glomerular function of kidney.
Q: Name the test to assess the glomerular function of kidney. (Topic: Organ Function Test)
A: Clearance Tests
Q: Name the clearance tests. (Topic: Organ Function Test)
A: Creatinine, Urea, Inulin, PAH
Correlation
Q: Mention the analytical importance of enzymes. (Topic: Enzymes)
A: Urease for urea estimation, GOD-POD for Glucose estimation, CHOD-POD for Cholesterol estimation
Q: Mention the enzyme specificity exhibited by Urease. (Topic: Enzymes)
A: Absolute Specificity
Q: Normal Range of Blood Urea. (Topic: Amino Acids & Proteins)
A: Normal blood urea concentration ranges between 15–40 mg/dl.
Q: Define Uremia. (Topic: Amino Acids & Proteins)
A: The term uremia is used to refer to elevated blood urea due to renal disease.
Q: Mention types of uremia with causes. (Topic: Organ Function Test)
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- Pre-renal
Severe dehydration, fevers, diabetic coma, thyrotoxicosis, severe burns and so on are pre-renal causes of elevated urea levels.
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- Renal
Blood urea is increased in kidney diseases such as, acute glomerulonephritis, pyelonephritis, polycystic kidney, nephrotic syndrome and so on.
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- Post-renal
When there is an obstruction to the flow of urine (e.g. stones, tumours, and stricture urethra, enlargement of prostate and so on) blood urea is elevated, due to the increased Reabsorption in the renal tubules.
Q: Urea estimation is part of which organ function tests? (Topic: Organ Function Test)
A: Kidney function tests.
Q: Name other routinely performed kidney function tests. (Topic: Organ Function Test)
A: Creatinine, Electrolytes- Na+/K+/Cl-
Q: Quantitative Creatinine estimation is done by which method? (Topic: Enzymes)
A: Jaffe’s Method
Q: Name antioxidant vitamins. (Topic: Antioxidant Defense System )
A: Vitamin C, E, Beta Carotene