Selenophosphate Synthetase: Physiology, Biochemistry, and Mechanism

The video tutorial covers the topic of gene expression, focusing on the central dogma and the roles of different types of RNA. It introduces selenocysteine, an amino acid involved in redox reactions, and explains its synthesis through a complex enzymatic process involving selenophosphate. The tutorial also delves into the mechanism of selenophosphate synthesis, highlighting the role of tautomerization and the involvement of specific enzymes.

What is the primary role of messenger RNA in gene expression?

• To transport amino acids to ribosomes

• To form the catalytic unit of ribosomes

• To carry genetic information from DNA to ribosomes

• To process other types of RNA

Which amino acid is known for its involvement in redox reactions?

• L-serine

• L-cysteine

• L-tyrosine

• Selenocysteine

What element replaces sulfur in selenocysteine?

• Phosphorus

• Selenium

• Nitrogen

• Oxygen

Which group in the periodic table contains oxygen, sulfur, and selenium?

• Group 7

• Group 6

• Group 4

• Group 5

What is the initial step in the hypothetical synthesis of selenocysteine?

• Nucleophilic attack by selenium on carbon

• Tautomerization

• Hydrolysis of ATP

• Formation of a double bond

What is the role of selenophosphate synthetase in selenocysteine synthesis?

• To synthesize ATP

• To transport selenium to ribosomes

• To catalyze the formation of selenophosphate

• To process mRNA

What is the main purpose of hydrolyzing adenosine diphosphate in the selenophosphate synthesis process?

• To create a leaving group

• To form a double bond

• To stabilize the enzyme

• To release free energy

What is the geometry of the pentavalent intermediate formed during selenophosphate synthesis?

• Tetrahedral

• Trigonal planar

• Trigonal bipyramidal

• Linear

What is the final product of the tautomerization process in selenophosphate synthesis?

• Adenosine monophosphate

• Protonated selenophosphate

• Orthophosphate

• Selenocysteine

What is the three-letter code for selenocysteine?

• SYN

• SEN

• SEL

• SEC