D-Amino Acid Oxidase Mechanism and Biology

The video explores the catabolism of D amino acids, focusing on the enzyme D amino acid oxidase. It explains the mechanism of this enzyme, including the formation of a Schiff base and the production of hydrogen peroxide. The video also discusses the significance of D amino acid oxidase in breaking down bacterial D amino acids, such as D alanine and D glutamate, and the potential implications for human health. Additionally, it covers the glyoxylate pathways and their role in metabolism, concluding with a brief introduction to racemase enzymes.

What is the primary challenge in catabolizing D amino acids compared to L amino acids?

• D amino acids are more stable.

• Enzymes for L amino acids cannot process D amino acids effectively.

• D amino acids are not found in nature.

• D amino acids do not form Schiff bases.

Which molecule is essential for the activity of D amino acid oxidase?

• Coenzyme A

• ATP

• NADH

• FAD

What is the initial product formed when D amino acid oxidase acts on a D amino acid?

• Alpha ketoacid

• Schiff base

• Hydrogen peroxide

• Ammonia

Why is hydrogen peroxide considered a toxic byproduct in the cell?

• It is not reactive.

• It can lead to the formation of hydroxyl radicals.

• It forms stable compounds.

• It is a strong acid.

What role do D amino acids play in bacterial cell walls?

• They are not present in bacteria.

• They are converted into L amino acids.

• They are incorporated into peptidoglycan.

• They are used as energy sources.

Which D amino acid is commonly found in bacterial cell walls?

• D lysine

• D serine

• D valine

• D alanine

What is a potential fate of glyoxylate in the human body?

• Formation of urea

• Conversion to pyruvate

• Formation of oxalate

• Conversion to glucose

What is the significance of racemases in amino acid metabolism?

• They synthesize amino acids from fatty acids.

• They convert D amino acids into L amino acids and vice versa.

• They convert amino acids into sugars.

• They break down amino acids into smaller peptides.

Which enzyme is responsible for converting L serine to D serine in humans?

• Serine transaminase

• Serine racemase

• Serine oxidase

• Serine dehydrogenase

What is the potential link between glyoxylate metabolism and kidney stones?

• Glyoxylate is stored in the kidneys.

• Glyoxylate is converted into uric acid.

• Glyoxylate is a major component of kidney stones.

• Glyoxylate forms insoluble salts with calcium.