BCOR 12 1nd Edition Lecture 11 Outline of Last Lecture I Biodiversity II Prokaryote Abilities III Prokaryote Reproduction IV Common Characteristics of Prokaryotes V Factors that cause high genetic variability in prokaryotes Outline of Current Lecture I Gram Dyed Bacteria II Metabolic Adaptations of Prokaryotes III Types of Prokaryotes based Metabolic and Nutritional Modes IV The Human Microbiome Current Lecture Gram Dyed Bacteria Bacteria can by dyed to determine how thick their cell walls are Gram positive bacteria are identified by a darkly stained prokaryotes due to thick walls of peptidoglycan Peptidoglycan type of polymer in TRUE bacterial cell walls consisting of sugars cross linked with proteins IMPORTANT NOTE Only BACTERIA have cell walls NOT Archaea Gram positive and gram negative identified bacteria are used in the medical field to determine if an antibiotic will or will not aid the patient Gram negative bacteria have a think layer of peptidoglycan AND an extra carbohydrate portion of a liposaccharide surrounding it so an antibiotic cannot kill gram negative bacteria as easily as gram positive bacteria We used to group the bacteria into separate kingdoms based on if they were gram positive or negative but this is not the case now based on new molecular evidence Metabolic Adaptations of Prokaryotes Possible Energy sources o SUN phototrophs o Chemical compounds chemotrophs These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Possible Carbon sources CO2 autotrophs Any other carbon source other than CO2 heterotrophs Prokaryotes are all over the place in terms of their energy source carbons source Types of Prokaryotes based on their Metabolic and Nutritional Modes Photoheterotrophs unique to prokaryotes Chemoheterotrophs most bacteria and many non prokaryotes Photoautotrophs plants Chemoautotrophs unique to prokaryotes Prokaryotes gather carbon and harvest energy is very diverse ways Eukaryotic photosynthesis is oxygenic oxygen producing Before oxygenic there was anoxygenic microbes prior to the oxygen revolution For anoxygenic microbes o Light drives the sugar synthesis o The electron donor in the energy synthesis was NOT H2O but H2S H2 or Ferrous iron Fe2 Eukaryotic cellular respiration is oxygen utilizing aerobic Anaerobic microbes do NOT use oxygen and to many is actually toxic Two types of anaerobic microbes o Obligate oxygen is toxic o Facultative can work with or without oxygen Prokaryotes have a great diversity in their metabolic and nutritional modes Microbial mats stromatolites are an example were created by communities of different microbes with different metabolic and nutritional modes Prokaryote phylogeny is changing due to recent molecular evidence the biological species concept does NOT apply here Horizontal gene transfer has driven a LOT of the variation in the bacteria and Archaea The Human Microbiome There are 10 microbial cells for each human cell There are 400 microbial genes for each human gene It is generally a mutualistic relationship between the bacteria and the human Eukaryotic excluding human cells bacteria and archaea all live within the human body Firmcutes gram positive a common types of prokaryote found in the human body and are non pathogenic Bacteroidetes gram negative are another common types of prokaryotes found in the human body and are also non pathogenic 1000 1 ratio between anaerobic and aerobic microbes The diversity of microbes varies greatly between person to person especially when compared from different global regions