Bell Ringer: Complete SRQ 9.4 #3 Learning Target: I can describe the general characteristics of kingdoms Archaebacteria and Eubacteria. Bell Ringer: Complete SRQ 9.4 #3 A cladogram is a diagram showing groups of related individuals. It is used to show the proposed evolution of species according to molecular analysis.

Learning Target: I can describe the general characteristics of kingdoms Archaebacteria and Eubacteria. Bell Ringer: Are harmful bacteria more or less of a problem then they were 200 years ago? Explain.

Kingdoms Archaebacteria, Eubacteria, and The Viruses Microbiology Part I Kingdoms Archaebacteria, Eubacteria, and The Viruses

Characteristics of Bacteria Microscopic – 1000 times smaller than most human cells Thrive in places where no other organism is known to exist. Procaryotic Lack organized nuclei Lack membrane bound organelles

Characteristics of Bacteria Pathogenic and non-pathogenic Primary decomposer organisms in soil and water Along with fungi Pathogenic – disease causing Most are not pathogenic

Kingdom Archaebacteria Archae- “ancient” Cell walls do not contain peptidoglycans Some of their genes resemble eubacteria and eukaryotic cells Live in extreme environments

Thermoacidophies Live in and around Highly acidic soils Hot springs Hydrothermal vents on ocean floor Use hydrogen sulfide for respiration.

Methanogens Live in anaerobic environments. Swamps Sewage Intestines of some animals Use H2 and CO2 for respiration Produce methane gas

Halophiles Live in environments with extremely high salt concentration Use salt for respiration Are able to spoil salted meats

Kingdom Eubacteria Larger classification of bacteria

Cyanobacteria (blue-green algae) Have essentially the same structure as bacteria except they lack flagella Most are colonial, forming filaments All contain chlorophyll a and carry on photosynthesis filaments (long, thin strands of cells) Certain cyanobacteria affect the taste or odor of water; others may produce poisons.

Bacterial Shapes and Colonies Coccus – spherical Bacillus – rod shaped Spirillum – spiral shaped Strep – chain Staph – groups or clusters

coccus pl cocci bacillus spirillum

Kingdom Eubacteria 2 of 11» Clockwise from upper left corner: Lactobacillus - found in intestines, produces vitamin K, lactase, and antimicrobials (probiotics in yogurt); Streptococcus – members of this group cause strep throat, meningitis, and scarlet fever, and the holes in Swiss cheese; Bacillus – Members of this group are antibiotics, antifungals, and insecticides. This group also contains Bacillus antraces (anthrax); Salmonella – passed in undercooked meat and raw eggs, causes food poisoning; Acetobacter (center) - makes vinegar (acetic acid);

Bacterial Cell Structure

Cell Walls and Capsules Cell membrane Cell wall Lacks cellulose Contains peptidoglycans found only in bacteria Gives cell wall rigidity Gram’s stain Capsule – made of gummy, complex carbohydrates Gram’s stain – method used to test bacteria for peptidoglycans Capsule protects the cell from environment The thickness of the capsule affects an organism’s ability to combat infection by that bacteria.

Cytoplasmic Structures Procaryotic DNA forms a double stranded, circular chromosome Appears in a non-membrane-bound nuclear area. Plasmids – smaller circular DNA chromosomes Not found in all bacteria Not essential for survival Mesosomes – twisted indentations of the plasma membrane with various enzymes attached to them. Ribosomes Mesosomes - The enzymes are used in various processes such as photosynthesis and respiration.

Locomotive Structures Flagella Vibrations caused by Brownian movement Flagella - lack the microtubule arrangement of those in eucaryotic cells. Vibrations caused by Brownian movement of water molecules.

Uses of Bacteria

Uses of Bacteria Genetically engineered bacteria is a source of insulin, HGH, blood proteins, and other protein products.

Learning Target: I can describe bacterial reproduction and growth. Bell Ringer: Using a Venn diagram, compare and contrast kingdoms Archaebacteria and Eubacteria.

Bacterial Reproduction Bacterial growth is limited by the environment. Bacteria reproduce by simple cell division that does not involve mitosis. Binary fission Despite their rapid rate of reproduction, bacterial growth is limited by the environment. Mitosis – division of nucleus

Transfer of Genetic Material Conjugation – DNA passes from one cell to the next. Pilus – conjugation tube Transformation – living cells take up the DNA of other bacteria Not sexual reproduction – no gametes or zygote formed Conjugation is not a mutual exchange

Transfer of Genetic Material Transduction – transfer of genetic material by means of a virus Bacteriophage May come from another bacterium or the virus itself

Bacterial Nutrition Autotrophs Heterotrophs Photosynthetic Chemosynthetic Heterotrophs Parasitic Saprophytic

Autotrophs Photosynthetic Chemosynthetic Photosynthetic bacteria contain bacteriochlorophyll, which is purple, red, or brown instead of green Chemosynthetic bacteria use energy obtained from inorganic molecules to synthesize sugar. These pigments allow photosynthesis in darker areas. These bacteria obtain hydrogen from hydrogen sulfide instead of water. Oxygen is usually not a product.

Heterotrophs Parasitic bacteria feed on a living host Obligate parasites Saprophytic bacteria feed on dead organic matter Most bacteria are heterotrophic Obligate parasites require the presence of living tissue in order to grow. Some of the enzymes secreted to digest external substances are important in the manufacture of cheese and other products.

Conditions of Bacterial Growth Moisture – all bacteria require moisture Temperature pH Nutrition

Conditions of Bacterial Growth Bacteria are highly specific regarding the environment in which they can grow and multiply.

Bacteria in Unfavorable Conditions Reduce metabolism Form endospores Bacteria may decrease activities, reducing their metabolism. Endospores are formed within the plasma membrane, developing several layers of hard materials around the nuclear area.

Bacteria and Oxygen Obligate anaerobes – grow only without the presence of free oxygen Obligate aerobes – grow only with free oxygen Facultative anaerobes – can grow as either anaerobes or aerobes

Controlling Bacteria in Foods Destroy bacteria Retard bacterial growth Destroy the bacteria present and seal the food in a container which does not permit the entrance of new bacteria. Place the food in an environment that will prohibit or retard bacterial growth.

Pathogenic Bacteria Rickettsiea Intracellular parasites Usually cause fevers, rashes, and blotches under the skin Rocky Mountain spotted fever, typhus

Pathogenic Bacteria Spirochetes Larger, corkscrew shaped Some are non-pathogenic Lack flagella Lyme disease, yaws, infectious jaundice, syphilis, relapsing fever

Pathogenic Bacteria Mycoplasmas Lack a cell wall and can assume many shapes