Prokaryotes

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Prokaryotes

• 1. Nuclear membrane absent
• 2. Genetic material- single coiled loop of DNA
• 3. Ribosomes
• 4. Chlorophyll, if present, not in chloroplasts
• 5. Flagella, if present, no 9-2 fibril
• 6. Cell wall, if present- peptidoglycan

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Eukaryotes

• 1. Nuclear membrane is present
• 2. Genetic material- chromosome pairs of DNA
  protein
• 3. Ribosomes, mitochondria, Golgi complex,
  endoplasmic reticuli
• 4. Chlorophyll, if present, chloroplasts
• 5. Flagella, if present, 9-2 fibril
• 6. Cell wall, if present- cellulose, chitin

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Prokaryotes (Bacteria Archaea)

• 1. Most are 1-10mm in length
• 2. Cell wall with plasma membrane
• 3. Peptidoglycan, unique amino acid disaccharide
  or lipid structure
• 4. Some capsule and/or slime layer (gelatinous
  sheath)

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Prokaryote DNA

• 1. Nucleoid- region containing a single looped
  chromosome
• 2. Plasmid- small accessory rings of DNA in some
• 3. Plasmids used as gene vectors in genetic
  engineering

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Endosymbiotic hypothesis

• 1. Heterotrophic bacteria became mitochondria of
  eukaryotes
• 2. Cyanobacteria became chloroplasts of
  eukaryotes
• 3. Spirochete bacteria became flagella of
  eukaryotes

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Prokaryotes Eukaryotes

• 1. Both have plasma membrane cytoplasm
  plasmids in some simple eukaryotes
• 2. Prokaryotes have a nucleoid region
• 3. Eukaryotes have a nucleus with a nuclear
  envelope

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Viri (Viruses)

• 1. Iwanowsky, 1892- tobacco mosaic virus,
  Tobamovirus
• 2. lt200nm across
• 3. Capsid- outer coat of protein
• 4. Core- DNA or RNA

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Living or Not

• 1. DNA or RNA, proteins, sometimes carbohydrates,
  lipids, enzymes
• 2. Mutate, adapt, evolve
• 3. No phospholipid membrane or metabolism
• 4. Acellular forms of life Weinberg, 1998

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Obligate Intracellular Parasites

• 1. Specific- bacteria, plant, or animal host
• 2. Viral nucleic acid takes over the metabolic
  machinery of host cell
• 3. Lytic and lysogenic cycle

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Lytic Cycle

• 1. Attachment- capsid combines with receptor

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Lytic Cycle

• 2. Penetration- viral nucleic acid enters host
  cell

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Lytic Cycle

• 3. Biosynthesis- viral components synthesized
  using cell organelles

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Lytic Cycle

• 4. Maturation- assembly of viral components

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Lytic Cycle

• 5. Release- lysis of host cell release of new
  viri

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Lysogenic Cycle

• 1. Between penetration biosynthesis
• 2. Viral nucleic acid is incorporated into host
  DNA passed along as cell reproduces
• 3. At some point, continues to biosynthesis . . .

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