BIOLOGY 1A03 Lecture Notes - Lecture 12: Catabolite Activator Protein, Cyclic Adenosine Monophosphate, Alternative Hypothesis

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Daniel Yang

Document Summary

Gene expression occurs when a gene product is actively being synthesized and used in a cell. Regulation of a gene expression is critical to the ef cient use of resources and so to survival. Escherichia coli has served as an excellent model organism for the study of prokaryotic gene regulation. Transcription and translation of genes in bacteria were predicted to be triggered by speci c signals from the environment. Fig 17. 1 - gene expression can be regulated at three levels. Genes can be under transcriptional, translational, or post-translational control. All three types of regulation occur in bacteria. Translational control allows a cell to quickly change which proteins are produced. Post-translational control provides the most rapid response but is energetically expensive. Some genes are constitutively transcribed, which means they are always expressed. Other genes are regulated and their expression may be induced or repressed. The level of expression of different genes can be highly variable.