Transcript Bacteria
Bacteria What you need to know!!!! What are Bacteria? They are prokaryotes that have cell walls containing peptidoglycans. Prokaryotes: Organisms who’s cells lack a nucleus Classifying Prokaryotes 2 main types 1. Eubacteria 2. Arachebacteria Eubacteria Live almost everywhere Have a cell wall Have a cell membrane Have cytoplasm No nuclei Archebacteria Live in extreme environments Have a cell wall No nuclei How do we identify Bacteria? Shape Cell wall How they move How they get energy Bacteria Shapes Rod shaped: Bacilli Spherical shaped: Cocci Spiral or Corkscrew: Spirilla Cell walls 2 Different ones in Eubacteria 1. Gram-positive: Purple when viewed under a microscope 2. Gram-Negative: Light pink or red when viewed How They Move Some don’t move at all Some have Flagella: a small whip-like structure that makes the bacteria move forward. Some snake or spiral forward Some glide along slowly How do They Obtain Energy? 2 Main ways 1. Heterotrophs: They get energy by eating other organic molecules 2. Autotrophs: They make their own food from inorganic molecules Types of Bacterial Heterotrophs Chemoheterotrophs: Take in organic molecules for both energy and carbon Photoheterotrophs: They are photosynthetic but still need organic compounds as a carbon source. Types of Bacterial Autotrophs Photoautotrophs: Uses light energy to convert carbon dioxide and water to carbon compounds. Chemoautotrophs: Makes organic carbon molecules from CO2 using energy from chemical reactions. How do Bacteria Release Energy? They use either cellular Respiration or Fermentation. Cellular Respiration: Releasing energy by breaking down glucose and other food molecules using oxygen. Fermentation: Cells release energy in the absence of oxygen. Different types of Bacterial Respiration Obligate Aerobes: Bacteria that must have a constant supply of oxygen in order to live. Obligate Anaerobe: Bacteria that does not need oxygen in order to survive. Facultative Anaerobes: Bacteria that can survive with or without oxygen. Growth and Reproduction of Bacteria Bacteria grow and divide at astonishing rates! Types: Binary Fission Conjugation Spore Formation Growth and Reproduction of Bacteria Continued… Binary Fission: Type of asexual reproduction in which a bacteria replicates its DNA and divides in half, producing two identical daughter cells. Conjugation: Sexual reproduction between two bacterial cells. They exchange genetic information. Spore Formation: Used to save itself in unfavorable conditions. How we use Bacteria for help!! Decompose dead matter and organisms To preserve food and beverages Yogurt Intestinal bacteria to help us digest food The END!!!!!