Biol 200B Lecture 3 Current LectureTree of LifeI. Phylogenetic tree of lifea. All organisms connected through similarities in their form and function; passage of genes along branches of treeII. Reading a phylogenetic treeIII. Speciesa. “unit” of biodiversityIV. Form and FunctionProkaryotes (chapter 29) I. Kingdoms and DomainsII. Archaea and BacteriaIII. Microbe Abundance and DiversityIV. Prokaryote Cell StructureV. Metabolic DiversityVI. Difference in quality of lifea. Germ Theory of Diseaseb. Koch’s Postulates Chapter 29 Prokaryotes: Bacteria and ArchaeaKingdoms: King Philip Crossed Over For Gold and Silver1. Plants 2. Animals3. Bacteria4. Fungi5. Protists6. Archaea3 Domains: Bacteria, Archaea, Eukarya - Archaea and Eukarya are sister groups- Prokaryotes o Oldest organisms on eartho Most diverseo Most numerouso Most robusto Most ecologically important Examine Table 29.1Microbe Abundance and Diversity:Diversity- 5000 species of bacteria and archaea have been described but millions exist- 400 species in the human digestive tractThese 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.- 128 species live in the lining of the stomach- 500 species live in the human mouthAbundance- 10% of the world’s biomass comprised of prokaryotes living under the ocean- 90% of the cells living on or in body are:– 1012 bacterial cells on your skin – 1014 bacterial and archaeal cells in your digestive tractStudying bacteria and Archaea:- Enrichment Culture- grow and study- Direct Sequencing-Most prokaryotic species have never been cultured or even seen, but their DNA is everywhereMicrobes:a. Size variesb. Shape variesc. Mobility variesProkaryote cell structure: - Tough cell wall- peptidoglycan (rigid network of polysaccharides and peptides)- Pili- for parasites fastens cell to host membrane- Flagella– rotating structureArchaea differ from Bacteria- RNA and ribosomal proteins more like those of Eukaryotes- Gram Stain- Bacteria have 2 kinds of cell walls:1. Gram-positive – thick layer of peptidoglycan2. Gram-negative – thin peptidoglycan between lipid bilayersMetabolic Diversity: The most important thing to remember about bacteria and archaea is how diverse they are in the types of compounds they can use as food2 requirements to stay alive:1. Source of energy to make ATP2. Source of carbon for biosynthesisSummary Table 28.3Bacteria and Archaea can live in extreme environments and use toxic compounds as food because they produce extremely sophisticated enzymes Two Key Ecological Services of Prokaryotes1. Oxygen Production in Early Earth 2. Nitrogen Fixation and Cycling Bacteria and Archaea are extremophiles- Thermophiles – temps 80-121⁰C - Acidophiles – pH < 1.0- Halophiles – very high salt- Water depths > 2500 m- AnoxiaBioremediation: some microbes “eat” toxic chemicals dumped in the environment by humansDifferences in quality of human life – sanitation, nutrition, vaccinesGerm Theory of Disease: microorganisms are the cause of many diseases- Microbes are transmitted from the sick to the healthy- Most bacteria are pathogenic Koch’s Postulates: (1910)1. Microbes must be present in the sick and absent from the healthy 2. Microbes are isolated from sick and grown in pure culture3. The microbes grown in pure culture must make the healthy sick4. Introduced cultured microbe that experimentally made animals sick must be isolated from those sick animalsAntibiotics: Alexander Fleming (1928) Bacteria did not grow near the fungus; fungus secreted penicillin, killing bacteriaBacteria reproduce asexually – direct transfer of genetic