BIOLOGY 207 Study Guide - Midterm Guide: Maltotriose, Entry Point, Maltose
Document Summary
Coli can grow in culture on glucose as the sole carbon source when inorganic phosphate, ammonia, sulfate, some salt, and a bit of iron are provided. This means e. coli can make all of its cellular constituents (lipids, protein, rna, dna, polysaccharide) from one simple sugar and a few minerals. Minimal medium (chemically-defined medium): a growth medium of this kind with a single sugar and any necessary minerals. Some promoters lack a recognizable -35 sequence; those promoters require regulatory proteins to assist rna polymerase core enzyme in recognizing and binding to the promoter. Transcriptional activator protein/activator protein/repressor protein: regulatory proteins that bind dna, usually as dimers, at specific sequence in the promoter via a helix-turn-helix motif at inverted repeats. One helix of each monomer associates with the dn, within the major grove. The other helix allows protein-protein contacts that hold the monomers together as dimer. Activator and repressor proteins control the transcription rate.