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Unformatted text preview: 11/8/2010 Regulation of protein synthesis- bacteria Genome of ecoli is represented by one DNA double helix- circle (no ns); contrains 4288 genes 4288 places where translation would stop/start Some of these genes are genes that code for rRNA; there are 3 kinds because there are 3 kinds of rRNA; some are tRNA (between 20-61 different transfer RNA genes; at least one for every amino acid and one for every codon); most of these 4k plus genes will be used for coding proteins Gene ZY can be transcribed into mRNA ZY As ribosomes connect to those mRNAs initiating protein synthesis, moving down RNAs and falling off, you get several ribosomes sitting there at the same time and you get polysome Polysome produce proteins Ribosomes connecting to mRNA A would form a polysome A and they would make protein A Ribosomes connecting to mRNA Betc Control metabolism by controlling the activity or amount of appropriate enzymes; control amount of enzyme protein Clicker- How many of the 4288 genes should normally be turned o (how many should be transcribed)? All could be transcribed and some be turned off allosterically, all could be transcribed and some are not translated for mRNA, some just be transcribed, or could depend on growth conditions. A: Some of control is allosteric; rate of function depends on nutrients available Rate of synthesis of each protein is orchestrated for balanced growth of generalized cells and for differentiation of specialized cells; ex. Carbon source, amino acids Look at balanced growth Example- Lactose utilization in E. Coli Lactose- combination of glucose and galactose Utilization of lactose requires uptake (carrier) and enzyme to breakdown the...
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