Characteristics of Living Things • Living things are made of cells. • Living things reproduce • Living things are based on genetic code • Living things grow and develop • Living things obtain and use energy • Living things respond to the environment • Living things maintain a stable internal environment • Living things change over time
Prokaryotes- simple cells Eubacteria- “normal” bacteria found everywhere Archaebacteria- unusual bacteria found in hot springs, brine pools and mud Eukaryotes- complex cells with nucleii Fungus- mold, mushrooms, etc. decomposers Protists- microscopic “left over” group Plants- make food Animals- consumers of food Today’s Modern Kingdoms 2 1
BacteriaHow is the world we live in impacted by things that you can’t see? Health & Social Education
Bacteria • Bacteria are living things that are neither plants nor animals. • Two Kingdoms: Eubacteria & Archaebacteria • Prokaryotes – all bacteria. have no nucleus or complex organelles
E. coli E. coli
Live in extreme environments Chemically different Cell wall lacks peptidoglycan (carbohydrate) Live in non-extreme environments Chemically different Cell wall contains peptidoglycan (carbohydrate) Archaebacteria vs. Eubacteria
Where??? • Eubacteria live almost everywhere: • Fresh water • Salt water • Land • On & within your body!
Archaebacteria • Chemically different from eubacteria • Lack peptidoglycan cell walls • DNA sequences differ from eubacteria • “Extremophiles” • Can live in extremely harsh environments • Acidic pH, temperature, saline, anaerobic(no oxygen)
Disease Caused by Bacteria • Pathogens-disease causing agents • Two ways bacteria cause disease • 1. Digesting cells • 2. Produce toxins
Preventing Bacterial Disease • Antibiotics: block the growth and reproduction of bacteria(not viruses) • Vaccines: weakened pathogens injected into body to produce resistance
Methods used to control bacterial growth… Sterilization by heat-great heat Disinfectants-chemical solutions that kill pathogenic bacteria Food storage and processing-refrigeration, canning, preservatives Dehydrate food
Importance of Bacteria • Decomposers • Recycle nutrients from dead organisms back into the ecosystem • Ex: A tree dies; bacteria attack and digest dead tissue, break it down into simpler material and return it to the soil.
Production of foods and beverages Oil spill clean up Removal of waste and poison from water Mining of minerals making essential vitamins in body Production of medicines and chemicals Human Uses of Bacteria
Where is good bacteria found? • Digestive tract • Skin • Mouth • Urinary tract • Genital areas
Bacteria Reproduction Binary Fission: 1.Doubles in size 2.Doubles DNA 3.Splits into two Conjugation: 1.Bridge forms between two cells 2.Genes move from one cell to another Endospore Formation: 1.Thick wall within bacteria forms to protect its DNA 2.Cell is now a spore, and goes into hibernation until more favorable conditions return
Growth Rates • Given good growing conditions, a bacteria can grow and divide at astonishing rates. • If the environment is optimal, bacteria cells can divide as often as every twenty minutes.
Typical Eubacterial Cell • Bacteria (prokaryotes) are simpler than eukaryotes • Cell wall: • Protects from injury • Determines shape • Made of peptidoglycan (carbohydrate molecules linked by proteins)
Shapes of Bacteria • Spiral-shapedSpirilla • Sphere-shapedCocci • Rod-shapedBacilli
Name the shape! 1 2 3 4 5