NPN

Sure! Here are 30 multiple-choice questions based on the content from the document "Lecture 3 NPNs":

### Multiple Choice Questions

1. What are non-protein nitrogen compounds (NPNs)?

- A) High molecular weight proteins

- B) Low molecular weight compounds containing nitrogen

- C) Only amino acids

- D) Complex carbohydrates

2. Where are NPNs primarily found in the body?

- A) In bones

- B) In urine

- C) In muscles

- D) In fatty tissue

3. What is the primary metabolic by-product of protein metabolism?

- A) Glucose

- B) Urea

- C) Lipids

- D) Creatine

4. Which of the following NPNs has the highest plasma concentration?

- A) Creatinine

- B) Urea

- C) Ammonia

- D) Amino Acids

5. What indicates renal function in relation to blood urea nitrogen (BUN)?

- A) Increased muscle mass

- B) Decreased renal perfusion

- C) High protein diet

- D) All of the above

6. What is the normal BUN range in mg/dL?

- A) 5-15

- B) 6-20

- C) 10-30

- D) 15-25

7. Which method is commonly used to measure urea levels?

- A) Direct Jaffe Reaction

- B) High-Performance Liquid Chromatography

- C) Gas Chromatography

- D) Mass Spectrometry

8. What is the main end product of purine metabolism?

- A) Creatinine

- B) Uric Acid

- C) Ammonia

- D) Glucose

9. What condition is characterized by an increased level of NPN in the blood?

- A) Hypoalbuminemia

- B) Azotemia

- C) Hyperkalemia

- D) Hyponatremia

10. Which of the following is a cause of pre-renal azotemia?

- A) Glomerulonephritis

- B) Dehydration

- C) Urinary obstruction

- D) Kidney stones

11. What does an elevated creatinine level typically indicate?

- A) Liver dysfunction

- B) Renal dysfunction

- C) Heart failure

- D) Thyroid disease

12. In which condition does urea accumulate due to kidney failure?

- A) Uremia

- B) Hypoalbuminemia

- C) Hyperuricemia

- D) Hyponatremia

13. What is the primary source of ammonia in the body?

- A) Protein metabolism

- B) Carbohydrate metabolism

- C) Fat metabolism

- D) Nucleic acid metabolism

14. Which NPN is synthesized in the liver from ammonia and carbon dioxide?

- A) Creatinine

- B) Urea

- C) Uric Acid

- D) Ammonia

15. What factor can falsely elevate urea measurement?

- A) Hemolysis

- B) Fluoride

- C) High protein intake

- D) Dehydration

16. What is the normal creatinine range for adult males in mg/dL?

- A) 0.6-1.2

- B) 0.5-1.1

- C) 1.0-1.5

- D) 1.2-1.8

17. What is the main function of the kidneys concerning NPNs?

- A) Synthesize proteins

- B) Excrete waste products

- C) Absorb nutrients

- D) Regulate blood pressure

18. Which condition is characterized by high uric acid levels?

- A) Gout

- B) Diabetes

- C) Hypertension

- D) Hyperlipidemia

19. What dietary factor can increase urea production?

- A) Low carbohydrate intake

- B) High protein intake

- C) Low fat intake

- D) Increased fiber intake

20. Which NPN is known to be a marker for renal function?

- A) Uric Acid

- B) Creatinine

- C) Ammonia

- D) Urea

21. What is the reference range for serum uric acid in adult males?

- A) 2.6-6.0 mg/dL

- B) 4.0-8.5 mg/dL

- C) 0.5-7.2 mg/dL

- D) 3.0-7.0 mg/dL

22. What is the major cause of hyperuricemia?

- A) Renal failure

- B) Liver disease

- C) Dehydration

- D) Excessive protein intake

23. What is a common analytical method for measuring uric acid?

- A) Direct Jaffe Reaction

- B) Ion-Selective Electrode

- C) High-Performance Liquid Chromatography

- D) Colorimetric assay

24. What can contribute to false decreases in creatinine measurement?

- A) High protein intake

- B) Hemolysis

- C) Bilirubin

- D) Dehydration

25. Which enzyme is involved in the conversion of creatine to creatinine?

- A) Creatinase

- B) Urease

- C) Ammoniase

- D) Dehydrogenase

26. What is the conversion factor for mg/dL to mmol/L for creatinine?

- A) 0.357

- B) 88.4

- C) 0.0595

- D) 76.25

27. Which condition is associated with low urea levels?

- A) Dehydration

- B) Liver disease

- C) High protein intake

- D) Renal failure

28. What is the primary function of the urea cycle?

- A) Synthesize glucose

- B) Convert ammonia to urea

- C) Produce energy

- D) Regulate electrolytes

29. What is the primary method used to measure ammonia levels?

- A) Spectrophotometric

- B) Ion-Selective Electrode

- C) Enzymatic method

- D) Colorimetric method

30. What is a significant clinical consequence of elevated ammonia levels?

- A) Muscle pain

- B) Encephalopathy

- C) Fatigue

- D) Hypertension

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