BIOC 3110 Lecture Notes - Lecture 32: De Novo Synthesis, Carbamoyl Phosphate, Aspartate Carbamoyltransferase
Document Summary
We previously talked about how amino acids are made; amino acids are also required to make a variety of biomolecules, one being de novo synthesis of nucleotides. Understand the nomenclature and the structural difference between bases: ribo- rna, has a ribose sugar. Nucleotide: adenylate: deoxyribo- dna, has a deoxyribose sugar attached. Base: adenine (same because no variation in base, just sugar) Two pathways for synthesis of pyrimidines: de novo pathway-synthesis from simple molecules, from scratch. Begin with an activated ribose, and combine amino acids, atp, and other precursors. Bicarbonate + nh3 (from glutamine) + 2 atp carbamoyl phosphate by cps ii. 2. carbamoyl phosphate + asparatate pyrimidine ring by aspartate transcarbamoylase. Stepwise phosphorylation by kinases utrip (rna form: salvage pathway-reusing existing nucleotides and modifying. Begin with activated ribose and a previous nucleotide that is broken down into bases, then bases are added to ribose to form a new nucleotide. This pathway when doing pyrimidines can form a nucleoside intermediate.