Biology 1290B Chapter Notes - Chapter 8: Metal Toxicity, Frederick Griffith, Cholera Toxin
Document Summary
The transforming principle was an early name for dna. In 1928, scientists didn"t know yet that dna carried genetic information, but they knew that there was something that could cause bacteria to transform from one type to another. Transformation occurs when one bacterium (you know, those microscopic, single-celled creatures) picks up free-floating dna and incorporates it into its own genome. The idea of the transforming principle was discovered during an experiment by frederick griffith. Supercoiling -> caused by naps (nucleoid-associated proteins: naps assist with twisting the dna helix and folding them into further loops, each forming a supercoiled domain (10,000 bases forming loops) Increase in genome size, increase in protein-coding genes. Most condensed to least condensed -> dna helix, looped domain structure, supercoiled domain, supercoiling, chromosome (without coiling) F plasmids allow for the transfer of genetic material from donor to recipient through a recombination process.