Biochemical Tests Quiz PDF

**Biochemical Tests** **Quiz** ======== 1. **What principle underlies the measurement of biomolecules in the laboratory?** a. A\) Molecules absorb light at a constant wavelength b. B\) Molecules absorb light energy at a specific wavelength for that molecule c. C\) Li...

**Biochemical Tests** **Quiz** ======== 1. **What principle underlies the measurement of biomolecules in the laboratory?** a. A\) Molecules absorb light at a constant wavelength b. B\) Molecules absorb light energy at a specific wavelength for that molecule c. C\) Light passes through solutions without any absorption d. D\) Molecules reflect light at a particular wavelength e. E\) Light energy is only absorbed by organic molecules 2. **Which of the following is commonly used to measure the absorbance of biomolecules in the laboratory?** f. A\) Microscope g. B\) Spectrophotometer h. C\) pH meter i. D\) Centrifuge j. E\) Thermometer 3. **What does the term \"optical density\" (OD) refer to in spectrophotometry?** k. A\) The concentration of a sample l. B\) The volume of the sample m. C\) The absorbance of light by the sample n. D\) The mass of the biomolecule o. E\) The wavelength of light used 4. **Which of the following describes a colometric assay?** p. A\) It measures the temperature of a sample. q. B\) It involves the formation of a color complex at a specific wavelength. r. C\) It uses a microscope to identify molecules. s. D\) It measures the optical density of the solution. t. E\) It calculates the concentration of a sample by its mass. 5. **How are unknown concentrations of biomolecules determined in spectrophotometry?** u. A\) By measuring the sample's color change v. B\) By comparing absorbance values to a standard curve w. C\) By calculating the weight of the sample x. D\) By using a reference sample with known concentration y. E\) By measuring the molecular size 6. **Which of the following is true about screening tests?** z. A\) They provide specific data on organ function. a. B\) They provide preliminary physiological data about general conditions. b. C\) They are only used to detect genetic disorders. c. D\) They are invasive and require surgical intervention. d. E\) They provide detailed data on specific body systems. 7. **Which sample source is commonly used for disease biomarker testing?** e. A\) Muscle tissue f. B\) Saliva g. C\) Hair h. D\) Bone marrow i. E\) Lung fluid 8. **What is the primary role of blood urea measurement?** j. A\) To measure kidney function and hydration status k. B\) To assess liver function l. C\) To determine blood glucose levels m. D\) To measure iron levels in the blood n. E\) To detect infection 9. **What does serum urea indicate when elevated?** o. A\) Liver disease p. B\) Kidney function alteration or dehydration q. C\) Increased protein intake r. D\) Reduced blood glucose levels s. E\) Hyperthyroidism 10. **What is a key difference between plasma and serum samples in blood tests?** t. A\) Plasma contains more glucose than serum. u. B\) Serum is obtained after clotting and centrifugation, plasma is not. v. C\) Serum is collected using anticoagulants, plasma is not. w. D\) Plasma is more suitable for glucose analysis than serum. x. E\) Serum has higher levels of blood cells than plasma. 11. **What is the significance of using venous blood samples for measuring blood cell contents?** y. A\) They are used for arterial blood gas analysis. z. B\) They provide information about glucose metabolism. a. C\) They are commonly used for tests like glycosylated hemoglobin. b. D\) They measure kidney function directly. c. E\) They provide the best indication of oxygen saturation. 12. **What does arterial blood gas analysis primarily assess?** d. A\) Blood glucose levels e. B\) Oxygen, carbon dioxide, and pH levels in blood f. C\) White blood cell count g. D\) Blood urea concentration h. E\) Electrolyte imbalance 13. **What is the main role of sodium in the body's electrolyte balance?** i. A\) It regulates blood glucose levels. j. B\) It controls water balance across compartments. k. C\) It functions as a coenzyme in biochemical reactions. l. D\) It maintains blood pH balance. m. E\) It helps in digestion and absorption of nutrients. 14. **Which test is used to monitor kidney function through urea measurement?** n. A\) Liver function test o. B\) Blood urea nitrogen (BUN) test p. C\) Complete blood count (CBC) q. D\) Blood glucose test r. E\) Creatinine kinase test 15. **Which of the following methods is used to measure the concentration of electrolytes like sodium and potassium?** s. A\) Enzyme-linked immunosorbent assay (ELISA) t. B\) Ion-selective electrodes (ISE) u. C\) Fluorescence spectrometry v. D\) Western blotting w. E\) PCR analysis 16. **In the case of a patient with metabolic acidosis, why does hyperventilation occur?** x. A\) To increase CO₂ in the body y. B\) To expel CO₂ and reduce H+ ions in the blood z. C\) To increase insulin production a. D\) To compensate for dehydration b. E\) To remove excess glucose 17. **What is the role of glutamate dehydrogenase (GLDH) in the urea measurement test?** c. A\) It converts ammonia and OG to glutamate. d. B\) It breaks down glucose into fructose. e. C\) It facilitates the breakdown of urea into CO₂ and ammonium. f. D\) It reduces NADH to NAD. g. E\) It prevents urea degradation in samples. 18. **Which sample type is typically used for detecting arterial blood gas abnormalities, such as in diabetic ketoacidosis?** h. A\) Venous blood i. B\) Arterial blood j. C\) Capillary blood k. D\) Serum l. E\) Plasma 19. **What does a positive result for cardiac troponin (TnT, TnI) indicate in a patient?** m. A\) Liver dysfunction n. B\) Renal failure o. C\) Myocardial infarction (heart attack) p. D\) Chronic dehydration q. E\) Hyperglycemia 20. **How is cardiac troponin detected using magnetic beads and antibodies?** r. A\) The beads interact with a specific epitope on TnT or TnI, producing light for measurement. s. B\) The antibodies directly bind to glucose molecules in the blood. t. C\) The magnetic beads increase the sensitivity of the spectrophotometer. u. D\) The light reaction produces fluorescence to visualize the troponin levels. v. E\) The antibodies prevent troponin degradation during storage. 21. **What is the primary role of glutamate dehydrogenase (GLDH) in the measurement of urea in clinical samples?** w. A\) To convert ammonia and OG to glutamate x. B\) To break down urea into ammonium and CO₂ y. C\) To reduce NADH to NAD z. D\) To convert glucose to fructose a. E\) To measure optical density of the sample 22. **In the measurement of urea, what does the decline in NADH concentration indicate?** b. A\) A decrease in ammonia concentration c. B\) A decrease in urea concentration d. C\) An increase in urea concentration e. D\) An increase in glucose concentration f. E\) An increase in protein metabolism 23. **Which of the following would most likely be a cause of electrolyte imbalance leading to increased sodium levels?** g. A\) Chronic renal failure h. B\) Hyperglycemia i. C\) Acute dehydration from vomiting j. D\) Liver failure k. E\) Chronic liver disease 24. **In the case study of a 35-year-old woman with diabetic ketoacidosis, why does hyperventilation occur?** l. A\) To compensate for metabolic acidosis by removing excess CO₂ m. B\) To increase oxygen levels in the blood n. C\) To reduce ketone body production o. D\) To stimulate insulin production p. E\) To raise blood glucose levels 25. **Which of the following best describes the function of anti-cTnl antibodies in detecting cardiac troponin?** q. A\) They bind to the TnI epitope and generate light in a luminometer. r. B\) They convert NADH to NAD in the test reaction. s. C\) They bind to the TnT epitope to facilitate ion-selective electrode analysis. t. D\) They prevent the breakdown of troponin during analysis. u. E\) They act as enzyme inhibitors to preserve the troponin in the sample. 26. **What is the role of sodium in maintaining electrolyte balance in the body?** v. A\) Sodium acts as a co-enzyme for biochemical reactions. w. B\) Sodium is primarily involved in pH maintenance. x. C\) Sodium is restricted to the extracellular fluid compartment. y. D\) Sodium is primarily involved in cellular metabolism. z. E\) Sodium helps regulate glucose levels in the blood. 27. **Which of the following is the primary reason why plasma samples are often preferred over serum for specific tests?** a. A\) Plasma contains more glucose than serum. b. B\) Plasma preserves certain analytes by preventing cellular metabolism. c. C\) Plasma is easier to obtain than serum. d. D\) Plasma is better for measuring blood cell contents. e. E\) Plasma contains higher levels of urea than serum. 28. **Which of the following conditions could lead to low serum urea levels?** f. A\) Kidney failure g. B\) Dehydration h. C\) Chronic liver disease i. D\) High protein diet j. E\) Diabetes mellitus 29. **What type of sample is most often used for detecting arterial blood gas abnormalities like pH or oxygen levels?** k. A\) Venous blood l. B\) Arterial blood m. C\) Capillary blood n. D\) Plasma o. E\) Serum 30. **What is the main advantage of using cardiac troponin (TnT and TnI) as a marker for myocardial infarction?** p. A\) It is highly specific for cardiac muscle damage. q. B\) It is found in high concentrations in all muscle tissues. r. C\) It provides an early indication of glucose metabolism. s. D\) It measures overall heart function in real-time. t. E\) It can also detect renal dysfunction. **Answer guide** ---------------- 1. **What principle underlies the measurement of biomolecules in the laboratory?** **Answer: B) Molecules absorb light energy at a specific wavelength for that molecule** **Explanation**: Each biomolecule absorbs light at a particular wavelength, and the amount of light absorbed is directly proportional to the concentration of the molecules in the solution. 2. **Which of the following is commonly used to measure the absorbance of biomolecules in the laboratory?** **Answer: B) Spectrophotometer** **Explanation**: A spectrophotometer measures the absorbance (optical density) of light by a sample, which is used to calculate the concentration of biomolecules in the sample. 3. **What does the term \"optical density\" (OD) refer to in spectrophotometry?** **Answer: C) The absorbance of light by the sample** **Explanation**: Optical density (OD) is a unit used to quantify how much light is absorbed by a sample, which correlates with the concentration of biomolecules. 4. **Which of the following describes a colometric assay?** **Answer: B) It involves the formation of a color complex at a specific wavelength.** **Explanation**: Colometric assays rely on biomolecules forming a color complex at a particular wavelength, which is then measured by spectrophotometry. 5. **How are unknown concentrations of biomolecules determined in spectrophotometry?** **Answer: B) By comparing absorbance values to a standard curve** **Explanation**: To determine unknown concentrations, a standard curve is created by measuring absorbance at known concentrations. The unknown concentration is then determined by comparing its absorbance to the curve. 6. **Which of the following is true about screening tests?** **Answer: B) They provide preliminary physiological data about general conditions.** **Explanation**: Screening tests are used to give initial information on a person's general health or physiological state. They don't provide detailed insights into specific organ function but serve as a starting point for further tests. 7. **Which sample source is commonly used for disease biomarker testing?** **Answer: B) Saliva** **Explanation**: Saliva is increasingly used for disease biomarker testing as it is non-invasive and can provide information for conditions such as drug use, oral infections, and certain diseases. 8. **What is the primary role of blood urea measurement?** **Answer: A) To measure kidney function and hydration status** **Explanation**: Blood urea levels are indicative of kidney function and hydration status, as urea is excreted by the kidneys. 9. **What does serum urea indicate when elevated?** **Answer: B) Kidney function alteration or dehydration** **Explanation**: High levels of urea in the blood can indicate impaired kidney function or dehydration due to conditions like vomiting or diarrhea. 10. **What is a key difference between plasma and serum samples in blood tests?** **Answer: B) Serum is obtained after clotting and centrifugation, plasma is not.** **Explanation**: Serum is collected after the blood has clotted and the cells are removed, while plasma is obtained from blood that has been anticoagulated to prevent clotting. 11. **What is the significance of using venous blood samples for measuring blood cell contents?** **Answer: C) They are commonly used for tests like glycosylated hemoglobin.** **Explanation**: Venous blood is frequently used for tests such as glycosylated hemoglobin, which is important for monitoring diabetes, as it reflects long-term glucose control. 12. **What does arterial blood gas analysis primarily assess?** **Answer: B) Oxygen, carbon dioxide, and pH levels in blood** **Explanation**: Arterial blood gas analysis measures key parameters like oxygen and carbon dioxide levels and pH, which are important for assessing respiratory function and acid-base balance. 13. **What is the main role of sodium in the body's electrolyte balance?** **Answer: B) It controls water balance across compartments.** **Explanation**: Sodium plays a key role in maintaining water balance between intracellular and extracellular compartments, as water moves to follow sodium. 14. **Which test is used to monitor kidney function through urea measurement?** **Answer: B) Blood urea nitrogen (BUN) test** **Explanation**: The BUN test measures urea levels in the blood and is used to assess kidney function. 15. **Which of the following methods is used to measure the concentration of electrolytes like sodium and potassium?** **Answer: B) Ion-selective electrodes (ISE)** **Explanation**: Ion-selective electrodes are used to measure specific ions like sodium, potassium, and chloride in blood and other body fluids. 16. **In the case of a patient with metabolic acidosis, why does hyperventilation occur?** **Answer: B) To expel CO₂ and reduce H+ ions in the blood** **Explanation**: Hyperventilation helps expel CO₂ from the body, which reduces the concentration of H+ ions, partially compensating for metabolic acidosis and raising the blood pH. 17. **What is the role of glutamate dehydrogenase (GLDH) in the urea measurement test?** **Answer: A) It converts ammonia and OG to glutamate.** **Explanation**: GLDH is used in the urea measurement test to convert ammonia and oxoglutarate (OG) into glutamate, which is part of the reaction process that leads to NADH measurement. 18. **Which sample type is typically used for detecting arterial blood gas abnormalities, such as in diabetic ketoacidosis?** **Answer: B) Arterial blood** **Explanation**: Arterial blood is used for blood gas analysis, especially in cases like diabetic ketoacidosis, where oxygen, carbon dioxide, and pH need to be measured directly from the arterial source. 19. **What does a positive result for cardiac troponin (TnT, TnI) indicate in a patient?** **Answer: C) Myocardial infarction (heart attack)** **Explanation**: Elevated cardiac troponin levels, particularly TnT and TnI, are specific markers for myocardial infarction (heart attack), indicating cardiac muscle damage. 20. **How is cardiac troponin detected using magnetic beads and antibodies?** **Answer: A) The beads interact with a specific epitope on TnT or TnI, producing light for measurement.** **Explanation**: Anti-cTnI antibodies are conjugated to magnetic beads and alkaline phosphatase. These antibodies bind to cardiac troponin, and the enzyme reaction produces light that is measured by a luminometer. 21. **What is the primary role of glutamate dehydrogenase (GLDH) in the measurement of urea in clinical samples?** **Answer: A) To convert ammonia and OG to glutamate** **Explanation**: GLDH plays a crucial role in the urea assay by converting ammonia and oxoglutarate to glutamate, which is part of the overall reaction that leads to the measurement of urea. 22. **In the measurement of urea, what does the decline in NADH concentration indicate?** **Answer: C) An increase in urea concentration** **Explanation**: The NADH declines as the urea drives the reaction forward, leading to more ammonia and, consequently, more NADH conversion to NAD, indicating higher urea concentrations. 23. **Which of the following would most likely be a cause of electrolyte imbalance leading to increased sodium levels?** **Answer: C) Acute dehydration from vomiting** **Explanation**: Dehydration, such as from vomiting, leads to loss of water, which concentrates sodium in the extracellular fluid, causing increased sodium levels. 24. **In the case study of a 35-year-old woman with diabetic ketoacidosis, why does hyperventilation occur?** **Answer: A) To compensate for metabolic acidosis by removing excess CO₂** **Explanation**: Hyperventilation in metabolic acidosis helps expel CO₂ from the body, thus reducing the acid burden (H+ ions) and helping to partially compensate for the acidosis. 25. **Which of the following best describes the function of anti-cTnl antibodies in detecting cardiac troponin?** **Answer: A) They bind to the TnI epitope and generate light in a luminometer.** **Explanation**: The antibodies are designed to bind specifically to cardiac troponin, allowing its detection through a light-emitting reaction, measurable by a luminometer. 26. **What is the role of sodium in maintaining electrolyte balance in the body?** **Answer: C) Sodium is restricted to the extracellular fluid compartment.** **Explanation**: Sodium primarily resides in the extracellular compartment and plays a key role in maintaining fluid balance by regulating osmolarity and water movement. 27. **Which of the following is the primary reason why plasma samples are often preferred over serum for specific tests?** **Answer: B) Plasma preserves certain analytes by preventing cellular metabolism.** **Explanation**: Plasma is preferred for tests that require preservation of certain analytes, as anticoagulants prevent blood cells from consuming the analytes (such as glucose). 28. **Which of the following conditions could lead to low serum urea levels?** **Answer: C) Chronic liver disease** **Explanation**: Chronic liver disease can cause low serum urea levels because the liver is responsible for synthesizing urea, and impaired liver function reduces urea production. 29. **What type of sample is most often used for detecting arterial blood gas abnormalities like pH or oxygen levels?** **Answer: B) Arterial blood** **Explanation**: Arterial blood is used for blood gas analysis, as it provides more accurate information regarding respiratory and metabolic functions, including pH, oxygen, and carbon dioxide levels. 30. **What is the main advantage of using cardiac troponin (TnT and TnI) as a marker for myocardial infarction?** **Answer: A) It is highly specific for cardiac muscle damage.** **Explanation**: Cardiac troponin is highly specific to cardiac muscle, making it an excellent biomarker for detecting myocardial infarction with minimal interference from other tissues.