PROKARYOTES AND EUKARYOTES.pdf

PROKARYOTES * evolved prior to the formation of nucleus * tend to be small, simple cells allowing dissolved substances can easily cross * contain protein filaments called pili (pilus) which project from the cell wall helping the cell to move across or cling to a surface * contain mesosomes that func...

PROKARYOTES * evolved prior to the formation of nucleus * tend to be small, simple cells allowing dissolved substances can easily cross * contain protein filaments called pili (pilus) which project from the cell wall helping the cell to move across or cling to a surface * contain mesosomes that function both for aerobic respiration and cell wall formation * with glycocalyx (capsule or slime layer) that enables certain bacteria to resist phagocytic engulfment by white blood cells * contain fimbriae which are responsible for the attachment of the cell to its host or substrate * contain endospore that allows a bacterium to produce a dormant and highly resistant cell * do not contain cytoskeleton EUKARYOTES * contain nucleus that protects and controls access to the cell’s DNA * tend to be large and complex * contain membrane-bound structures * cytoskeleton is present Benefits of Prokaryotic and/or Eukaryotic Organisms 1. food * bacteria, often Lactobacillus, along with yeasts and molds (eukaryotes), have been used for thousands of years to make fermented foods such as cheese, pickles, soy sauce, vinegar, wine, beer, and yogurt 2. pollution clean-up * bioremediation is any process that uses microorganisms, fungi, green plants, or their enzymes to clean a contaminant from the environment * bacteria that can digest the hydrocarbons in petroleum (oil) can be used to clean up oil spills 3. biomining (microbial miners) * the use of prokaryotes to extract certain minerals from ores * the use of a bacterium such as Thiobacillus ferooxidans to leach copper from mining leftovers has improved recovery rates and reduced operating costs for mining companies 4. waste disposal and biogas production * aerobic and anaerobic bacteria are used to decompose sewage waste by breaking down organic matter into harmless, soluble sludge in settling tanks while the methane gas produced is used as an energy source such as fuel to produce electricity, heat buildings and water, or power vehicles 5. agricultural uses * prokaryotes and other microorganisms also have important roles in biogeochemical cycles, the cycles that move molecules and nutrients through the biotic and abiotic parts of the environment such as nitrogen, carbon, and phosphorus cycles 6. pest control * Bacillus thuringiensis are Gram-positive, soil-dwelling bacteria that are used to control certain plant pests by producing endotoxin (called Bt toxin) that is toxic to mosquitoes, moths, and certain caterpillars but does not affect humans, wildlife, pollinators, and most other beneficial insects, such as ladybugs and bees