GEN-3020 Lecture Notes - Lecture 14: Structural Gene, Type System, Tryptophan
Document Summary
Gen 3020: chapter 16-regulation of gene expression in. Genes are dna sequences that are transcribed into rna. Structural gene is a dna sequence that encodes a protein that functions in metabolism or biosynthesis or that plays a structural role in the cell. Regulatory gene is a dna sequence that encodes a protein or rna molecule that interacts with dna sequences and affects their transcription or translation or both. Regulatory element is a dna sequence that affects the transcription of other dna sequences to which it is physically linked, not transcribed. Constitutive gene is not regulated and is expressed continually. Prokaryotes regulate gene expression in response to environmental conditions. Bacteria adapt to environment by producing inducible enzymes only when specific substrates are present. Enzymes are continuously produced regardless of chemical makeup of environment. Abundance of end product in environment represses gene expression. Regulation of inducible or repressible type system under positive or negative control.