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:
1 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 it can use- explain 2 Review List three ecological roles played by prokaryotes Explain Why are nitrogen fixing bacteria so important
3 Classifying Prokaryotes Unicellular organisms that lack a nucleusHas DNA, but it is not found in a membrane- bound nuclear envelope.
4 Prokaryotes are classified as Bacteria or Archaea Two of the three domains of life.
5 Bacteria Larger of the two groups Do not agree exactly how many phyla Live almost everywhere.
6 Surrounded 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.
7 Archaea 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.
8 Three Archae Varieties ThermoacidophilesLive in hot and acid environments such as hot springs and coal debris, still keep internal pH around 7.
9 Three Archae Varieties 2. HalophilesLive in high salt concentrationsOcean borders, great salt lake, dead sea.
10 Three Archae Varieties 3. MethanogensProduce methaneAnaerobicLive in thick mud and the digestive tracts of animals.
11 Size, 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.
12 Nutrition and Metabolism Store energy as sugarsEnergy is released during cellular respiration, fermentation, or both.
15 Growth 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.
16 Mutation Mutations are one of the main ways prokaryotes evolve Mutations are inherited by daughter cells produced by binary fission.
17 Conjugation Exchange of genetic information in prokaryotes Hollow bridge forms between two bacterial cellsGenetic material, usually a plasmid, moves from one cell to the other.
18 The Importance of Prokaryotes Essential in maintaining every aspect of the ecological balance of the living world.
19 Decomposers Decompose complex organic molecules into simpler molecules Supply raw materialsTreat industrial sewagePurify waterProduce fertilizer.
20 Producers Among the most important producers Many food chains dependant on them.
21 Nitrogen 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.
22 Human Uses of Prokaryotes Yogurt, sauerkraut, and buttermilkDigest petroleum and remove human-made waste from waterSynthesize drugs and chemicals.