Dopachrome Tautomerase: Physiology, Biochemistry, and Mechanism

The video explores the mechanism and physiology of the enzyme dopethrone tautomerase, also known as DOPA Chrome isomerase. It discusses the synthesis of melanin in melanocytes, focusing on the role of tyrosinase and DOPA Chrome tautomerase in converting DOPA to DOPA Chrome and further to dihydroxy indole carboxylic acid. The video explains the enzyme's structure, function, and the catalytic role of zinc cations and water molecules in the active site. The spontaneous and enzymatic pathways of the reaction are also covered.

What is the primary focus of the video tutorial?

• It is an optional educational resource for those interested in chemistry.

• It is a video about general biology.

• It is a required part of the anatomy and physiology class.

• It is a mandatory video for all students.

What is another name for the enzyme dopethrone tautomerase?

• DOPA Chrome isomerase

• Melanosome

• Tyrosinase

• L-Tyrosine

What are the two types of melanin mentioned in the video?

• Tyrosinase and dopethrone

• L-Tyrosine and DOPA Chrome

• Melanosome and melanocyte

• Eumelanin and pheomelanin

What is the role of tyrosinase in melanin synthesis?

• It converts DOPA to DOPA Chrome.

• It synthesizes L-Tyrosine.

• It is a structural protein.

• It breaks down melanin.

Where is the active domain of tyrosinase located?

• Inside the nucleus

• On the cell surface

• Facing the melanosome lumen

• In the cytosol

What role do zinc cations play in the active site of dopethrone tautomerase?

• They hold water molecules in place.

• They are catalytically active.

• They are structural components.

• They are not involved in the reaction.

What is the function of water molecules in the catalysis process?

• They act as a base and an acid.

• They provide structural support.

• They are not involved.

• They inhibit the reaction.

What is the driving force behind the tautomerization process?

• Formation of two aromatic rings

• Conversion of DOPA to DOPA Chrome

• Breakdown of L-Tyrosine

• Synthesis of melanin

What is the significance of the delta G value in the reaction?

• It means the reaction is reversible.

• It suggests the reaction is slow.

• It shows the reaction is endothermic.

• It indicates a spontaneous reaction.

What is required for the spontaneous occurrence of the reaction?

• Presence of metal cations

• High temperature

• Low pH

• Absence of enzymes