Eukaryotes

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Eukaryotes

• Functional Anatomy and Eukaryotic Microbes

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Eukaryotes

• DNA in nucleus, surrounded by membrane
• DNA in several chromosomes
• DNA associated with histones and nonhistone
  proteins
• Other organelles include endoplasmic reticulum,
  Golgi, lysosomes, mitochondria, chloroplasts

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Eukaryotes

• Cell walls chemically simple (none in animal
  cells)
• Usually divide by mitosis
• 10-100mm in diameter
• Algae, fungi, protozoa
• Animal and plant cells

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Evolution of Eukaryotes

• First living cells were prokaryotes
• Endosymbiotic theory
• Organelles inside eukaryotic cells arose from
  engulfed prokaryotic cells
• Mitochondria and chloroplasts have DNA that
  resembles prokaryotic DNA
• Ancestors of mitochondria were O2-requiring
  bacteria
• Ancestors of chloroplasts were photosynthetic
  bacteria

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Emergence of Eukaryotic Cells
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There exist Contemporary Endosymbionts

• Photosynthetic cyanobacteria (pink) inside
  flagellated protozoan Cyanophora

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Eukaryotic Cell Structures
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External Structures to Know

• Flagellum
• Cilia
• Glycocalyx
• Cell Wall (fungi)
• Plasma membrane

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Eukaryotic Flagella
92 arrangement of microtubules in- side a
flagellum
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Glycocalyx

• Complex multi-sugar polysaccharide
• Plus fibers, capsule or slime layer

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Cell Walls

• Algae cellulose, pectin, mannans, SiO2,
  CaCO3
• Fungi chitin (poly NAG)
• Yeasts glucan and mannan
• Protozoa pellicle instead of cell wall

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Internal Structures to Know

• Nucleus
• Endoplasmic reticulum / ribosomes
• Golgi apparatus
• Lysosome
• Mitochondria
• Chloroplasts
• Notice all the complex internal membranes!

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Nucleus
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Rough Endoplasmic Reticulum
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Smooth Endoplasmic Reticulum / Golgi
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Lysosomes
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Lysosomes
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Mitochondria
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Chloroplasts
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Eukaryotic Microbes

• Fungi
• Protists
• Algae
• Protozoa
• Helminths (multicellular animals, worms, not
  really considered microbes)

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Fungi
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Fungi

• Largest living beings
• Michigan fungus extended across 40 acres, est.
  weight 10 tons
• Hyphae (hypha) are long filaments
• Spores germinate to form new fungus
• Can reproduce sexually or asexually
• Very important ecologically the degraders

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Fungi

• Yeasts are unicellular others are multicellular
• Most are saprophytic
• Beneficial fungi
• decompose dead plants
• symbiotically help plants absorb water and
  nutrients
• are farmed by ants for food
• are eaten by humans
• produce foods and medicines

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Pathogenic Fungi

• Fungal diseases are mycoses
• Cutaneous mycoses
• Fungi have keratinase degrade keratin on skin,
  nails and hair
• Systemic Mycoses
• Spread throughout the body

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Pathogenic Fungi

• Examples ringworm, athletes foot

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Pathogenic Fungi

• Systemic mycoses
• Usually caused by soil fungi
• Special problems in immunocompromised hosts
• Example Valley Fever
• Coccidioides immitis

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Protists Algae and Protozoa

• Algae photosynthetic protists
• Aquatic
• Rarely pathogenic, if ever!
• Primary medical threat is from neurotoxins

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A Pathogenic Algae Pfiesteria piscicida

• A pathogenic Dinoflagellate
• Dinoflagellates known for red tides
• Inhalation causes neurological, skin, eye,
  respiratory and gastrointestinal symptoms

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Lichens Symbiosis Between Fungus and Alga
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Protozoa

• 65,000 species!
• Single-celled
• Most are non-pathogenic and free-living (water)
• Complex life cycles
• Protective capsule is called a cyst

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Protozoan Morphology
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A Pathogenic Flagellated Protozoa

• Giardia lamblia giardiasis
• infects small intestines

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A Pathogenic Flagellated Protozoa

• Trypanosoma cruzi
• Chagas Disease infects nervous system and heart
• carried by kissing bugs
• 16-18 million infections, 50,000 deaths / year

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Helminths
Multicellular macroscopic animals
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Pathogenic Helminths

• Flukes
• Tapeworms
• Hook worms
• Pin Worms

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What You Should Know

• Similarities and differences between prokaryotic
  and eukaryotic cells
• Location and function of all structures discussed
  in class

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What You Should Know

• Morphology of eukaryotic microbes
• unicellular or multicellular
• beneficial uses
• example pathogens

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What You Should Know

• Types of eukaryotic microbes
• fungi (most macroscopic)
• algae (some macroscopic)
• lichens (macroscopic)
• protozoa (unicellular)
• helminths (macroscopic)