1 / 14

Exploring Prokaryotes: Diversity, Structures, and Functions

Delve into the world of prokaryotes, unicellular organisms without a nucleus, found in diverse environments. Learn about their classifications, shapes, reproduction methods, and importance in various ecosystems. Discover how prokaryotes aid in decomposition, sewage treatment, nitrogen fixation, and more. Explore their significance in food production, waste removal, pharmaceutical synthesis, and adaptation to extreme conditions. Uncover the intriguing roles of Bacteria and Archaea in the ecosystem.

zgifford
Download Presentation

Exploring Prokaryotes: Diversity, Structures, and Functions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 20: Viruses and Prokaryotes Section 20-2: Prokaryotes

  2. Classifying Prokaryotes • Unicellular organisms that lack a nucleus • DNA free-floating • Two groups domains: Bacteria and Archae

  3. Bacteria • Larger domain • No agreement about number of phyla • Live everywhere – fresh/salt water, land, within other eukaryotes, etc • Usually have a cell wall for shape and protection – contains peptidoglycan • Escherichia coli – found in human intestines – have extra membrane around cell wall for more protection • Flagella for movement, pili to anchor bacterium

  4. E. coli

  5. Archae • Look similar to Bacteria under a microscope • Cell walls contain lipids • DNA more like eukaryotes • Many live in harsh/extreme environments – salt lakes, hot springs, no oxygen, etc

  6. Structure and Function • Range in size from 1-5 micrometers • Come in three shapes: • Bacillus (pl. bacilli) – rod shaped • Coccus (pl. cocci) – spherical • Spirillum (pl. spirilla) – spiral/corkscrew shaped • Also three arrangements: • Diplo- (in a pair) • Staphlyo (in a bunch) • Strepto- (in a chain)

  7. Shapes/Arrangements

  8. Structure and Function • Can be distinguished by how and if they move – flagella, slime • Energy released during cellular respiration, fermentation, or both • Vary in the way they obtain energy

  9. Growth, Reproduction, and Recombination • Binary fission occurs when a prokaryote has doubled in size – replicates its DNA and splits • Asexual reproduction • Can be very fast when conditions right • When conditions are unfavorable, many prokaryotes form endospores • Thick wall forms around DNA and part of cytoplasm • Can stay dormant from many years • Bacillus anthracis

  10. Growth, Reproduction, and Recombination • Mutations allow prokaryotes to evolve - inherited through binary fission • Many prokaryotes also exchange genetic information through conjugation • Hollow bridge forms between 2 bacterial cells and genetic information (usually plasmids) move from one cell to another • Increases genetic diversity

  11. Importance of Prokaryotes • Decomposers – break down complex organic molecules into simpler ones, supplying raw materials needed • Actinomycetes in soil • Sewage treatment • Water purification • Production of fertilizers • Producers – cyanobacteria responsible for photosynthesis in ponds/aquatic environments • Nitrogen fixers – convert atmospheric nitrogen gas into usable forms • Symbiotic relationships with plants – Rhizobium and legumes

  12. Human Uses of Prokaryotes • Foods/commercial products (yogurt produced with Lactobacillus) • Digest petroleum • Remove human-made wastes and poisons from water • Synthesize drugs, chemicals by genetic engineering • Those adapted to extreme environments may produce heat-stable enzymes

More Related