Kingdom Bacteria, Kingdom Archaea, and Viruses

Outline Cellular Detail and Reproduction of Bacteria Classification of Bacteria Kingdom Bacteria  Phylum Bacteriophyta - Class Bacteriae - Class Cyanobacteriae - Class Prochlorobacteriae Kingdom Archaea Viruses

Features of Kingdoms Bacteria and Archaea All have prokaryotic cells. Nutrition is primarily by the absorption of food in solution through the cell wall. Reproduction is predominately asexual, by means of fission.

Cellular Detail and Reproduction of Bacteria Plasma folds and other membranes apparently perform some of the functions of the organelles of eukaryotic cells. Plasmids may be present.  Replicate independently of large DNA molecule. Mitosis does not occur.  Internal reorganization of material during which two DNA molecules migrate to opposite ends of the cell.

Cellular Detail and Reproduction of Bacteria Three Forms of Genetic Recombination  Conjugation - DNA transferred from donor cell to recipient cell.  Transformation - Living cell acquires DNA fragments released by dead cells.  Transduction - DNA fragments carried from one cell to another by viruses.

Classification of Bacteria Most bacteria are less than 2 or 3 micrometers in diameter. Occur primarily in three forms:  Cocci - Spherical or Elliptical  Bacilli - Rod shaped or Cylindrical  Spirilla - Helix or Spiral

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Kingdom Bacteria - The True Bacteria Phylum Bacteriophyta  Class Bacteriae - Unpigmented, Purple, and Green Sulfur Bacteria.  Most are heterotrophic.  Majority are saprobes.

Kingdom Bacteria - The True Bacteria  Some are Autrophic. - Purple Sulfur, Purple Non-Sulfur and Green Sulfur Bacteria  Some are Chemotrophic. - Iron, Sulfur, and Hydrogen Bacteria

Kingdom Bacteria - The True Bacteria Human Relevance of Class Bacteriae  Composting - Allow bacteria to decompose organic waste.  Diseases - Modes of Access  Air  Sneezing

Kingdom Bacteria - The True Bacteria Modes of Access  Contamination of Food and Drink - Salmonella - Legionnaire Disease - Botulism  Direct Contact - Syphilis and Gonorrhea - Anthrax

Kingdom Bacteria - The True Bacteria Modes of Access  Wounds - Tetanus and Gangrene  Insect Bites and Other Organisms - Bubonic Plague - Tularemia - Rickettsias - Mycoplasmas - Lyme Disease

Koch’s Postulates Rules for proving a particular microorganism is the cause of a particular disease.  Microorganism must be present in all cases of the disease.  Microorganism must be isolated from the victim in pure culture.

Koch’s Postulates  Microorganisms from the pure culture must be able to infect hosts.  Microorganism must be isolated from the experimentally-infected host and grown in pure culture for comparison with the original culture.

True Bacteria Useful to Humans Insecticide  Bacillus thuringiensis and Bacillus popilliae Bioremediation  Explosives  Petroleum Vision  Rhodopsin production

True Bacteria Useful to Humans Dairy Products  Cheese, yogurt Human Health  Aid in digestion  Elimination of yeast infections Industrial Uses  Photographic film  Acetone

Class Cyanobacteria The Blue Green Algae  Distinctions between traditional bacteria and cyanobacteria. - Cyanobacteria have chlorophyll a and oxygen is produced when they undergo photosynthesis. - Cyanobacteria contain phycobilins. - Cyanobacteria can both fix nitrogen and produce oxygen.

Class Cyanobacteria Form, Metabolism, and Reproduction  Cells in about half of the approximately 1,500 species are blue-green in color.  Produce a nitrogenous food reserve called cyanophycin.  Do not produce gametes or zygotes and do not undergo meiosis.

Class Cyanobacteria Human Relevance  Included among the many aquatic and photosynthetic organisms at the bottom of various food chains.  Often become abundant in bodies of fresh water in warmer months. - Algal Blooms  Swimmers Itch  Nitrogen Fixation

Class Prochlorobacteriae The Prochlorobacteria  Have chlorophyll a and b of higher plants, but no trace of the phycobilin accessory pigments of cyanobacteria. - Adds to theory that chloroplasts may have originated from cells living within the cells of other organisms.

Kingdom Archaea One of two distinct lines of most primitive organisms.  Metabolism is fundamentally different from other lines of bacteria. Methane Bacteria  Killed by oxygen and active only under anaerobic conditions. - Energy derived from the generation of methane gas from carbon dioxide and hydrogen.

Kingdom Archaea Salt Bacteria  Metabolism enables these bacteria to thrive under extreme salinity. - Carry on simple photosynthesis with the aid of bacterial rhodopsin. Sulfolobus Bacteria  Metabolism allows these species to thrive at very high temperatures. - Also found in acidic hot springs.

Human Relevance of Archaebacteria Methane has a high octane level.  Given off by bacteria as they digest organic wastes in the absence of oxygen. - Sludge makes an excellent fertilizer.

Viruses Consist of a nucleic acid core surrounded by a protein coat.  Separated first according to the DNA or RNA. - Next grouped according to size and shape, nature of protein coats, and number of identical structural units in their cores.  Bacteriophages - Viruses that attack bacteria.

Phage Virus

Viral Reproduction Viruses can only replicate at the expense of their host cells.  Attach to susceptible cell. - Penetrate to cell interior.  DNA or RNA dictates synthesis of new molecules.  New viruses released from host cell.  Some can mutate very rapidly. - Immunity becomes more difficult.

Human Relevance of Viruses Annual loss in work time due to common cold and influenza viruses alone amount to millions of hours.  Immunizations have dramatically decreased incidence of many viruses such as German Measles, Mumps, and Chicken Pox. AIDS  Retrovirus - Evolves extremely quickly.

Viroids and Prions Viroids - Circular strands of RNA that occur in the nuclei of infected plant cells.  Transmitted from plant to plant via pollen, ovules, or machinery. - Cause more than a dozen plant diseases. Prions - Appear to be particles of protein that cause diseases of animals and humans.  No nucleic acids yet detected.

Review Cellular Detail and Reproduction of Bacteria Classification of Bacteria Kingdom Bacteria  Phylum Bacteriophyta - Class Bacteriae - Class Cyanobacteriae - Class Prochlorobacteriae Kingdom Archaea

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