Presentation on theme: "Bacteria Objective: G3 - Describe bacterial structure, & summarize the role of bacteria in both maintaining & disrupting the health of both organisms &"— Presentation transcript:
Bacteria Objective: G3 - Describe bacterial structure, & summarize the role of bacteria in both maintaining & disrupting the health of both organisms & ecosystems
Bacteria singular: bacterium / plural : bacteria ▪Microscopic Prokaryotes ▸ LACK CELL NUCLEUS ▪Until recently, bacteria were placed into one Kingdom -Kingdom Monera, hence sometimes bacteria are referred to as Monerans ▪Most numerous organisms on earth Before the doctors told us of the danger of a kiss I considered kissing you nothing short of bliss But now I know the danger and I sit and sigh and moan -- Six billion small bacteria, and I thought we were alone.
Kingdom Monera Is now two kingdoms: ▪Kingdom Eubacteria (true bacteria) –Tend to be smaller –Classified according to their mode of getting nutrients, mechanism of movement, and their shape ▪ Kingdom Archaebacteria (ancient bacteria) –Tend to be larger –Tend to live in extreme environments
Diversity Metabolic ▪ Some are heterotrophs (get energy by consuming organic molecules made by other organisms) and some are autotrophs (make their own food)
Diversity of Bacteria Naming ▪Cocci - sphere ▪Bacilli - rods ▪Spirilla - spirals Staph - in clusters Strep - in chains
Reproduction ▪Binary fission - one cell splits into two cells, offspring are genetically identical to parent ▪Conjugation - a form of sexual reproduction where bacteria exchange genetic information before dividing, offspring have new genes (and new traits)
Beneficial Bacteria ▪Main decomposers of dead organisms to recycle nutrients ▪Breakdown chemical & oil spills ▪Soil enrichment ▪Preservation by pickling ▪Fermentation ▪Live in intestines and help organisms digest food (exp. E. coli ) Harmless and beneficial bacteria far outnumber harmful varieties.
Harmful Bacteria ▪Some bacteria are known as pathogens ▪Cause disease ▪Can produce poisonous toxins
Bacteria Motility (ability to move) ▪Flagella – whiplike tail ▪Pili – tiny hairlike projections ▪Gliding over slime they secrete
Antibiotics (means against life) ▪Used to fight harmful bacteria, but sometimes it hurts the beneficial bacteria too ▪Does not work on VIRUSES because they are NOT LIVING ▪Inhibit the growth of or destroy bacteria