Presentation on theme: "1 Review In what ways do prokaryotes differ from one another Evaluate Use pg 486. Which category of prokaryote is the most flexible in the energy sources."— Presentation transcript:
11 Review In what ways do prokaryotes differ from one another Evaluate Use pg 486. Which category of prokaryote is the most flexible in the energy sources it can use- explain 2 Review List three ecological roles played by prokaryotes Explain Why are nitrogen fixing bacteria so important
3Classifying Prokaryotes Unicellular organisms that lack a nucleusHas DNA, but it is not found in a membrane- bound nuclear envelope.
4Prokaryotes are classified as Bacteria or Archaea Two of the three domains of life.
5Bacteria Larger of the two groups Do not agree exactly how many phyla Live almost everywhere.
6Surrounded by a cell wall that protects the cell from injury and determines its shape Contains peptidoglycanSome have flagellaPiliServe mainly to anchor the bacterium to a surface or to other bacteria.
7Archaea Look very similar to bacteria But Walls of archaea lack peptidoglycanMembranes contain different lipidsDNA sequences of key archaea genes are more like those of eukaryotes than those of bacteriaLive in extremely harsh environments.
8Three Archae Varieties ThermoacidophilesLive in hot and acid environments such as hot springs and coal debris, still keep internal pH around 7.
9Three Archae Varieties 2. HalophilesLive in high salt concentrationsOcean borders, great salt lake, dead sea.
10Three Archae Varieties 3. MethanogensProduce methaneAnaerobicLive in thick mud and the digestive tracts of animals.
11Size, Shape, and Movement BacilliRod-shaped prokaryotes.CocciSpherical prokaryotes.SpirillaSpiral and corkscrew-shaped prokaryotesAlso be distinguished by whether they move and how they move1-5 micrometers.
12Nutrition and Metabolism Store energy as sugarsEnergy is released during cellular respiration, fermentation, or both.
15Growth and Reproduction Binary fissionReplicates its DNA and divides in half, producing two identical cellsAsexualDoes not involve the exchange or recombination of genetic informationWith optimal conditions can replicate every 20 minutesEndosporeThick internal wall that encloses the DNA and a portion of the cytoplasm during unfavorable conditions.
16Mutation Mutations are one of the main ways prokaryotes evolve Mutations are inherited by daughter cells produced by binary fission.
17Conjugation Exchange of genetic information in prokaryotes Hollow bridge forms between two bacterial cellsGenetic material, usually a plasmid, moves from one cell to the other.
18The Importance of Prokaryotes Essential in maintaining every aspect of the ecological balance of the living world.
19Decomposers Decompose complex organic molecules into simpler molecules Supply raw materialsTreat industrial sewagePurify waterProduce fertilizer.
20Producers Among the most important producers Many food chains dependant on them.
21Nitrogen FixersNitrogen in atmosphere is not useable by the majority of speciesNitrogen-fixing bacteria and archaea provide 90 percent of the nitrogen used by other organismsLegumesSymbiotic relationship between plants and nitrogen fixing bacteria that live in nodules in the plant’s roots.
22Human Uses of Prokaryotes Yogurt, sauerkraut, and buttermilkDigest petroleum and remove human-made waste from waterSynthesize drugs and chemicals.