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Science
gene regulation
gene regulation Describe how gene regulation occurs in bacteria? Gene regulation in bacteria occurs in prokaryotes. Bacteria cells exist independently, each cell must perform to live. Bacteria grows rapidly with short lives carrying only what is necessary. Prokaryotic gene regulation is economy; transcription controlling is the most profitable way to regulate. Most genes are regulated into operons to synthesize certain gene products. Through the Operon concept constitutive enzymes constantly divide at a slow rate as an active repressor (Protein). Each operon has a single promoter region upstream, from the protein-coding regions. Two types of operons are inducible (on), and repressible (off), the transcription level control in the operon is controlled by an operator (sequence of bases that overlaps the promoter and serves as a regulatory switch). These two operon’s are under negative control, when the repressor protein binds to the operator, transcription of the operon is turned off. Regulation requires rapid turnover of mRNA molecules to prevent messages from being over translated. Bacteria do not usually harm proteins to regulate enzyme levels. When cells are starved of amino acids protein-digesting enzymes are needed to recycle them. One gene regulation system in bacteria is involved with anabolic pathways, in which amino acids and other essential molecules are synthesized from other precursors. Regulation in these pathways involves repressible enzymes coded for repressible genes. This is the Tryptophan operon, where genes code for enzymes that synthesize the amino acid tryptophan are organized in a repressible operon. For example, in the bacteria Salmonella, the operon consists of five structural genes that code for the enzymes required for synthesis of the amino acid tryptophan. Bibliography:
Word Count: 267
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