CHAPTER 3: AMOEBAS Flashcards
First identified the taxonomy of Amoeba coli (E. histolytica) in St. Peterburg, Russia
Fedor Losch (1875)
Description of 3 species as being human parasites.
Clifford Dobel (1919)
Description of 3 species of amoebas
E. histolytica - 4 nuclei
E. coli - 8 nuclei
E. gingivalis - in oral cavity
Identified E. hartmanni, morphologically similarly in size w. other amoebas
von Prowazek (1912)
identified E. dispar, no ability ti cause disease in human and animals
Emile Brumpt (1925)
ameba isolates from:
a. asymptomatic
b. amebic dysentery
Sargeaunt and Williams
ASYMPTOMATIC
Nonpathogenic zymodemes
AMEBIC DYSENTRY
Pathogenic zymodemes
General Characteristics of Protozoans
- animal-like protozoans
- unicellular
- multiply by BINARY FISSION
- no cell wall (PERIPLAST)
- 1 nucleus
- vacuolated
- facultative or obligate
Organs for Locomotion
- flagella
- pseudopods
- cilia
- apical complex not used for locomotion
Organism that contains APICAL COMPLEX
Plasmodium spp.
2 similar Entamoeba species that can only be distinguished by Polymerase Chain Reaction (PCR)
- histolytica and dispar
Life Cycle of an Amoeba
- Trophozoites
- Pre-cyst
- Cyst
- Metacyst
2 regions of cytoplasm
- Endoplasm
- Ectoplasm
single mass of aggregate of granules, maybe near the center of the cell or at times surrounded by chromatin particles that appear to be arranged on a chromatic network or chromatin granules lining the nuclear membrane
Nucleus/ Karyosome
maintain normal osmotic pressure by collecting excess water within their cytoplasm and expelling it outside
Contractile Vacuole
connects the nucleoplasm to the endoplasm
Nuclear membrane
envelops endoplasm; discharges metabolism
Ectoplasm
locomotion of amoeba; “false feet”
Pseudopods
locomotion of flagellates; hair-like projections of the cytoplasm arising in the kinetoplast functions as locomotion of organelles
Flagella
locomotion of ciliates; arise from basal granules within the ectoplasm and distributed over the surface of the body
Cilia
responsible for food waste and excretion discharge
Cytopyge