Biochemistry 3382A Lecture 2: Dr. Ball's Lecture 2.docx

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 3382A
• Professor: David Litchfield

Document Summary

Lecture 2 - regulation of nucleotide pools cont"d. In pyrimidine ribonucleotide biosynthesis, the ring is made first and then you stick it on the ribose. In contrast for purine biosynthesis, you start with the ribose and build the ring right on ribose. In pyrimidine biosynthesis, the first three steps include the construction of the ring and the addition of the prpp is the addition of the ribose. Utp and ctp and making sure that they are balanced: balancing the levels of purine and pyrimidine nucleotides. You should balance the amount of atp and gtp with utp and ctp. Reaction rates are adjusted with inhibition + activation. In e. coli, the ctp inhibits atcase, which is the enzyme that converts carbamoyl phosphate to carbamoyl aspartate. In animals, utp and udp will come back and inhibit carbamoyl phosphate (cp) synthase. Also in animals the ump will inhibit its own synthesis/formation.