Discuss the use of alternate sigma factors in global regulation:
Can immediately change expression of genes.
How transcription normally works: a sigma factor is involved in binding to the promoter of each gene, whether this binds depends on the positive and negative control. Sometimes the cell produces other sigma factors! The cell produces sigma 70 when it is in the lag phase, when it is produced it can now do the same thing as the main sigma factor but it will be preferential towards specific genes, these genes would be important in the exponential cycle. Sigma S is produced when the cell is in stress (stationary phase). Sigma C gets made in hot conditions.