Nucleotide Metabolism | Purine Biosynthesis 1: Up to IMP

The video tutorial explains the biosynthesis of inosine monophosphate (IMP), a key purine nucleotide. It covers the initial steps of purine synthesis, starting with ribose 5-phosphate from the pentose phosphate pathway, and the formation of PRPP. The tutorial details the assembly of the purine ring on the ribose, highlighting the role of various enzymes and the use of ATP. The process involves multiple steps, including the conversion of GAR to FGAM and the cyclization to form the complete purine ring. The video concludes with the potential pathways for IMP to form AMP and GMP.

What is the role of inosinate (IMP) in purine synthesis?

• It serves as a precursor for AMP and GMP.

• It is used directly in protein synthesis.

• It is a waste product of purine metabolism.

• It is incorporated into RNA and DNA.

Which enzyme is responsible for the conversion of ribose 5-phosphate into PRPP?

• GAR synthetase

• PRPP synthetase

• FGAM synthetase

• IMP cyclohydrolase

What is the significance of the nitrogen orientation in purine synthesis?

• It influences the nucleotide's electrical charge.

• It is crucial for the attachment of the nitrogenous base.

• It affects the color of the nucleotide.

• It determines the solubility of the nucleotide.

Which molecule is formed by the action of GAR synthetase?

• FGAR

• PRPP

• GAR

• IMP

What is the role of ATP in the formation of FGAM?

• It provides energy for the reaction.

• It acts as a substrate for the reaction.

• It is a byproduct of the reaction.

• It inhibits the reaction.

Which enzyme catalyzes the cyclization to form the five-membered ring in purine synthesis?

• FGAM synthetase

• PRPP synthetase

• AIR synthetase

• GAR synthetase

What happens to IMP after its synthesis in the purine pathway?

• It is stored in the cell for later use.

• It is directly incorporated into DNA.

• It is degraded into uric acid.

• It branches into the synthesis of AMP and GMP.