Kingdoms: Archaebacteria & Eubacteria

The Basic Bacteria Cell Bacteria cells have a simple structure: Cell Wall Cell Membrane Cytoplasm Ribosomes Genetic Material: DNA Flagella: a whip-like structure for movement THINK! - How is bacteria cell different from a plant/animal cell? Bacteria cells have no nucleus or organelles (other than ribosomes)

Two Kingdoms of Bacteria Archaebacteria “Ancient Bacteria” Cell Walls do not have peptidoglycan (sugar) Live in EXTREME environments Hot springs Very salty waters Sewage Eubacteria “New Bacteria” Cell walls contain peptidoglycan (sugar) Live almost anywhere Soil Inside organisms

Bacteria Structure: Shapes Bacteria cells have one of three basic shapes: rod shaped, spherical, & spiral. TRY THIS! Use a compound microscope to observe the structure of these different bacteria! Bacillus – rods “Bars” Coccus – spheres “Circles” Spirillum - spirals

How fast can bacteria multiply? TRY THIS! Each cup represents a generation of bacteria. Look at the cups in front of you and figure out how fast bacteria can multiply. Under ideal conditions, bacteria can reproduce as often as every 20 minutes! Calculate how many bacteria would there be after 3 hours. 512

Reproduction in Bacteria Binary Fission: This is where one cell divides to form 2 identical cells. The process involves only 1 parent. Therefore, it is considered asexual reproduction. Steps: DNA replicates Cell Splits

Obtaining Energy Autotrophs Heterotrophs These bacteria make their own food Some get energy from the sun Some get energy from chemicals Heterotrophs These bacteria that seek out their food They feed off of milk, meat, and decaying material THINK! - Do you think all bacteria need oxygen to survive? Aerobes: Need oxygen VS. Anaerobes: DO NOT need oxygen

Where Can We Find Bacteria? TRY THIS! Think of 4 objects in this classroom you think might contain a lot of bacteria. We will swab these areas and allow the bacteria to grow on agar plates. After 24 and 48 hours we will be able to observe how much bacteria is found in these locations!

Bacteria In Nature TRY THIS! Bacteria can act as “nature’s recyclers”: Observe these two pieces of lettuce. What do you notice? Bacteria can act as “nature’s recyclers”: Bacteria in soil break down dead trees, leaves, and animals These bacteria are known as decomposers

Bacteria In Nature Bacteria can cause diseases such as: Tooth decay – Streptococcus mutans Lyme disease – Borrelia burgdorferi http://www.underourskin.com/ Tetanus – Clostridium tetani Tuberculosis – Mycobacterium tuberculosis Salmonella – Salmonella enteritidis Pneumonia – Streptococcus pneumoniae THINK! - What can doctors prescribe to kill growing bacteria? Antibiotics

…But antibiotics don’t always work This is due to the fact that bacteria can rapidly mutate and become resistant to antibiotics. The mutated ones survive after the antibiotics are gone. Antibiotics attack and kill off bacteria without the mutation. They reproduce, passing along the mutation to their offspring. Eventually there are more antibiotic- resistant bacteria than non-resistant.

Bacteria in Nature Humans use certain bacteria to manufacture food products such as: Cheese Yogurt Sour cream Pickles Sauerkraut Apple Cider TRY THIS! Use a compound microscope to observe the natural bacteria found in yogurt! OR – Watch this clip from United Streaming on “Bacteria in Society”