Module 4: Non-Protein Nitrogens

Question 1

Urea

Answer 1

Excretory product of amino acid catabolism; formed from ammonia in the liver

Question 2

Urea reference range

Answer 2

2.5 - 8.5mmol/L

Question 3

Creatinine

Answer 3

Waste byproduct of the dehydration of creatine and the hydrolysis of creatine phosphate in neurons and muscle cells

Question 4

Uric acid

Answer 4

Major end product of purine metabolism (components of nucleotides, nucleosides and nucleic acids)

Question 5

How can interference from non-creatinine chromogens be reduced using a kinetic Jaffe method?

Answer 5

By monitoring the change in A over time. Interfering compounds react at different rates and times than creatininie. The differential reaction rates are used to identify creatinine from interferences

Question 6

Creatinine clearance can be used as an indicator of:

Answer 6

Glomerular filtration rate

Question 7

Reference range for creatinine clearance

Answer 7

1.20 - 2.30 mL/sec

Question 8

Formula for calculation of creatinine clearance

Answer 8

CC = U x V x 1.73 / P x 86400 x A