Urate Oxidase and Urate (Part 1): Physiology, Biochemistry, and Mechanism

The video tutorial covers purine catabolism, focusing on urate oxidase. It explains the enzyme's role in converting urate to hydroxy isocyanurate, a process not occurring in humans due to the transcriptional inactivity of the urate oxidase gene. The tutorial discusses the implications of this inactivity, leading to hyperuricemia and gout. It also delves into the detailed mechanism of urate oxidase, highlighting the enzyme's catalytic process and the formation of hydrogen peroxide as a byproduct.

What is the initial molecule in the purine catabolism pathway discussed in the video?

• Inosine monophosphate

• Adenosine monophosphate

• Guanosine monophosphate

• Xanthine

Which enzyme is responsible for converting hypoxanthine to xanthine?

• Urate oxidase

• Purine nucleoside phosphorylase

• Adenosine deaminase

• Xanthine oxidase

Why is urate oxidase not expressed in humans?

• It is inhibited by uric acid

• The gene is absent in humans

• The gene is transcriptionally inactive

• Humans have a different enzyme

What is the end product of purine catabolism in humans?

• Xanthine

• Hypoxanthine

• Hydroxy isocyanurate

• Urate

What condition is characterized by elevated urate levels in the blood?

• Hypouricemia

• Hypoglycemia

• Hyperuricemia

• Hyperglycemia

Which protein in the nephron is involved in urate excretion?

• SLC 2A9

• GLUT4

• AQP2

• Na+/K+ ATPase

What is the result of urate crystallization in the body?

• Hypertension

• Diabetes

• Gout

• Kidney stones

Where do urate crystals typically accumulate in the body?

• Heart

• Liver

• Big toe

• Lungs

What is the final product formed by the action of urate oxidase?

• Hydroxy isocyanurate

• Urate

• Xanthine

• Hypoxanthine

What type of reaction is involved in the mechanism of urate oxidase?

• Condensation

• Reduction

• Oxidation

• Hydrolysis