Ch 22- Protists

• microbe: organisms too small to see with the human eye
• protists: all eukaryotes, except for plants, fungi, and animals
• protists are paraphyletic
• Primary Endosymbiosis

  1. infoldings in the plasma membrane of an ancestral prokaryote (archaean) pinch off to form nucleus and endoplasmic reticulum
  2. the ancestral prokaryote extends part of its membrane out to consume a proteobacteria that evolves into mitochondria
  3. the heterotrophic cell now has a double membrane because of the vesicle that engulfed the proteobacteria thinking it was going to consume it , and the cell is now a modern heterotrophic eukaryote
  4. the cell then consumes a cyanobacteria that evolves into chloroplasts, and the cell is now a photosynthetic eukaryote
• Secondary Endosymbiosis:

  1. a photosynthetic eukaryotic cell is consumed by a bigger eukaryotic cell and the consumed cell now acts as chloroplasts for the new, big cell
• Evidence to Prove Endosymbiosis:

  1. organelles act as own cells with DNA
  2. mitochondria and chloroplast have own DNA as well as the cell's DNA
  3. DNA similarity with Archaeans
  4. mitochondria and chloroplasts go through cell division, translation, and transcription
  5. double membranes around organelles
  6. DNA in chloroplasts and mitochondria similar to cyanobacteria and proteobacteria
• primary producers: autotrophic, take out CO2, put in O2, do photosynthesis, provide food, very important to life on earth
• heterotrophs: organisms that obtain energy from other organisms
• symbionts= bacteria, fungi, protists, algae
• mixotrophs: can use both light and dark to photosynthesise
• Excavata: all have DNA similarity
• • too much primary producers= bad thing, will kill organisms, cause red tide
  • not enough primary producers= food will not be made and organisms in the food web will die off
• Excavata:

  1. diplomonads
  2. parabasalids
  3. euglenozoans
• Eukaryotic Supergroups:

  1. Excavata
  2. SAR
  3. Archaeplastida
  4. Unikonta
• SAR:

  1. Stramenopiles
  2. Alveolates
  3. Rhizarians
• Stramenopiles:

  1. diatoms
  2. brown algae
• Archaeplastida:

  1. Red algae
  2. Chlorophytes (green algae)
  3. Charophytes (green algae)
• Unikonta:

  1. amoebozoa- amoeba