MIC 102- Final Exam Guide - Comprehensive Notes for the exam ( 88 pages long!)
Document Summary
Microbes are free living organisms so small that they are only visible under the microscope . Except when they"re not: epulopiscium fishelsoni is huge, mycobacterium leprae is not free living, viruses aren"t even organisms. Base changes indicate divergence from common ancestors. Too many genes to keep track of so . We need a molecular clock: selectively neutral changes, conserved regions, found in all organisms. Small subunit (16s) rrna gene generally fits the bill. Surface to volume ratio is the key. For a sphere, doubling r increases sa by 4 times and volume by 8 times. Larder cells need tricks to increase sa. Example: intestine more surface area with same volume (packed tightly) Example: mitochondria more folds to increase surface area. Photosynthetic bacteria (cyanobacteria) oxygenated the planet (~2. 3billions years ago) Microbes are heavily involved in various biogeochemical process (carbon and nitrogen cycle) Gut bacteria help you make vitamin b and k.
