md 2

• Cyanobacteria is photosynthetic bacteria
• black smoker

  • shape: cork-screw
  • 400 C, very hot
  • Found: Crustal Plate boundaries
  • allows heat to come out when moved
  • chemoautotrophs: make energy for life
  • give life to prokaryotes
  • archaea eat from black smoker
• Archaea

  • live in extreme environments
  • thermophiles - love extreme temperatures
• Tube worms

  • 6 feet long, very big
  • live where heat from crust of Earth comes out
  • Eukaryotes, multicellular
  • no mouth, no anus
• How do tube worms eat?

  • bacteria are chemoautotrophs
  • cell in tube worm holds chemoautotroph bacteria cell
  • glucose feeds the tube worm
  • endosymbiosis
• symbiosis is two species interacting with each other
• endosymbiosis is the engulfing of an bacteria cell in a regular cell
• Clams are eukaryotes and do endosymbiosis
• Shrimp

  • not endosymbiosis
  • hold archaea near hot plates
  • eat whatever is produced from archaea
• Deep sea communities: Modes of Nutrition

  1. reliant on Bacteria and archaea
  2. most of the large organisms live in symbiosis with chemotropic bacteria, symbiosis is mutualistic
  3. most of the free-living prokaryotes are Archaea, that are adapted to extreme environments
• Modes of Nutrition

  • heterotrophs
  • photoheterotrophs
  • chemoautotrophs
• heterotrophs need a source of organic carbon for their food
• photoheterotrophs use light to make glucose
• chemoautotrophs need chemicals from reactions to create energy
• Similarities b/w Archaea and Bacteria

  • Binary Fission --> split, not meiosis and not mitosis
  • haploid
  • circular DNA
  • unicellular (mostly)
• Eukaryotic cells (difference)

  • Structures: nuclear envelope, linear chromosomes, mitochondria, cytoskeleton, organelle enclosed by membranes
  • reproduction: mitosis, meiosis (sex), mostly diploid
  • Cell: unicellular, multicellular
• similarity b/w Eukaryotic and Archaea: RNA polymerase consisting of > 10 subunits
• single-celled Eukaryotes are within the group - protists
• prokaryotic vs. Eukaryotic

  • prokaryotic: no nucleus
  • eukaryotic: mitochondria, nucleus with linear chromosomes, phagocytosis, primary: cyanobacteria
• Origin of nucleus

  1. chromosomes and plasma membrane
  2. infoldings of plasma membrane around chromosomes: invagination
  3. Eukaryotic cell, arises with infoldings and forms nuclear envelope and ER
• nuclear membrane = double membrane
• other formations for nucleus

  1. eukaryotes package their DNA to chromosomes
  2. Eukaryotes undergo mitosis
  3. eukaryotes have a diploid phase in their life cycle
• endosymbiosis theory

  • within, between two organisms where one organism is within the other
  • the origin or mitochondria and chloroplasts
  • phagocytosis - engulfing
  • mutualistic symbiosis - can't live on their own
  • endosymbiont - internal symbiont, help with cellular metabolism
• The origin of mitochondria

  1. Host cell surrounds and engulfs bacterium (phagocytosis)
  2. bacterium lives within host cell (endosymbiont)
  3. endosymbiosis: host cell supplies bacterium with protection and carbon compounds
  4. Bacterium supplies host cell with ATP
• The origin of Chloroplasts (photosynthesis)

  1. cyanobacterium engulfed by eukaryotic cell (phagocytosis)
  2. Symbiosis leads to photoautotrophic eukaryote
  3. culture cyanobacterium: they rely on each other
• Secondary endosymbiosis --> eukaryote eats another one

  1. photosynthetic protist is engulfed
  2. Nucleus from photosynthetic protist is lost
  3. organelle has 4 membranes
• Giardia lamblia (thought to have lacked mitochondria)

  • protists, "missing link" between eukaryotes and prokaryotes
  • parasitic zooflagellate: features --> two haploid nuclei; two nuclei
  • primitive eukaryote
  • nuclei evolution
• nuclei evolution of Giardia Lamblia

  1. haploid prokaryote
  2. primitive eukaryote with single haploid nucleus
  3. primitive eukaryote with two haploid nuclei
  4. eukaryote with single diploid
• Evidence that supports endosymbiosis of mitochondria and chloroplasts

  1. they are the right size to come from prokaryotic cells
  2. their membranes have enzyme and transport systems similar to prokaryotes
  3. organelles' dividing, splitting process is similar to binary fission
  4. machinery for DNA replication and translation (Small and prokaryote-like)
  5. more similar to prokaryotic genes than eukaryotic genes
• binary fission

  1. parent cell has: chromosome, cell wall, cytoplasm, cytoplasmic membrane
  2. replication of DNA: 2 cells are forming not yet separated
  3. segregation of DNA
  4. cell splits
• paraphyletic group is a group that contains some but not all the descendants from a common ancestor
• Euglenids

  • guts of termites
  • Trichonympha species
  • bacterial symbiont: able to process wood
• protists --> Apicomplexans

  • plasmodium falciparum causes Malaria
  • parasitic single-celled eukaryotes that move by flexion
  • complex-life cycle of plasmodium
• Protists

  • all eukaryotes that are not animals, plants or fungi
  • are not a monophyletic or "natural group" (paraphyletic)
• Archaea and Bacteria

  • binary fission (divide to make new cells): asexual reproduction by separation of the body into two new bodies
  • organization of DNA (shape is circular)
  • one copy of their DNA (haploid)
  • unicellular