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Prokaryotes

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2. Genetic material- chromosome pairs of DNA & protein ... 6. Cell wall, if present- cellulose, chitin. Prokaryotes (Bacteria & Archaea) ... – PowerPoint PPT presentation

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Title: Prokaryotes


1
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

2
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

3
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)

4
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

5
Endosymbiotic hypothesis
  • 1. Heterotrophic bacteria became mitochondria of
    eukaryotes
  • 2. Cyanobacteria became chloroplasts of
    eukaryotes
  • 3. Spirochete bacteria became flagella of
    eukaryotes

6
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

7
Viri (Viruses)
  • 1. Iwanowsky, 1892- tobacco mosaic virus,
    Tobamovirus
  • 2. lt200nm across
  • 3. Capsid- outer coat of protein
  • 4. Core- DNA or RNA

8
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

9
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

10
Lytic Cycle
  • 1. Attachment- capsid combines with receptor

11
Lytic Cycle
  • 2. Penetration- viral nucleic acid enters host
    cell

12
Lytic Cycle
  • 3. Biosynthesis- viral components synthesized
    using cell organelles

13
Lytic Cycle
  • 4. Maturation- assembly of viral components

14
Lytic Cycle
  • 5. Release- lysis of host cell release of new
    viri

15
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 . . .

16
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