Ch 4: Eukaryotic Microbes Flashcards
What are Eukaryotes?
Complex cells with a nucleus and other organelles
What are the types of Eukaryotic microbes?
Fungi, Protists, Multicellular parasites
What is endosymbiosis?
Eukaryotic cells evolved by endosymbiosis
- Early eukaryotic cells took up bacterial cells that could produce ATP (mitchondria/ATP)
- Increase in energy production allowed eukaryotes to form complex intracellular organization
The theory of endosymbiosis describes the evolution of which two eukaryotic organelles?
Mitochondria and Chloroplasts
Which structure is not found in all eukaryotes?
Flagella
What are the characteristics of Eukaryotic Flagellum?
Motility
- 9+2 arrangement of microtubules
- Cells can have more than one
- Found on some types of motile algae and protozoa
- Not found on fungi
What are the characteristics of Eukaryotic Cilium?
Translates to “eyelid”
-Similar arrangement as flagella
What are Eukaryotic cell walls composed of?
SImple Polysaccharides
- Cellulose (algae)
- Chitin (fungi)
What are Sterols?
Eukaryotic cells produce sterols which stabilize cell membranes
-many antifungal agents destabilize the fungal membranes by targeting the sterols
The cell wall of fungi is composed of?
Chitin
What are the characteristics of the Eukaryotic Nucleus?
- genome consists of loose, unpackaged DNA called chromatin
- nucleolus is the site of large amounts of rRNA synthesis (used for making ribosomes)
Eukaryotes have multiple linear chromosomes. How many chromosomes does yeast have?
Yeast has 16 chromosomes
What are the types of cellular reproduction?
Asexual
- mitosis
- budding (yeasts)
- binary fission (some simple protozoa)
Sexual
-meiosis → produces gametes (sex cells)
What are the characteristics of Eukaryotic ribosomes?
ribosomes perform translation (protein synthesis)
- ribosomes are present in cytoplasm & RER
- 80S ribosomes (60S + 40S subunits)
What are the characteristics of Rough Endoplasmic Reticulum?
“rough” (RER)
-contain ribosomes that synthesize membrane proteins and proteins to be secreted
“smooth” (SER)
- lipid synthesis
- vesicles for packaging proteins for transport
What are the characteristics of the Golgi Apparatus?
- Makes modifications (glycosylation) to proteins that are going to be transported
- Packaging into membrane enclosed vessicles
- Secretion
How does phagocytosis work in Eukaryotes?
Microbes are ingested and compartmentalized into phagosomes or vacuoles
Lysozomes produced in Golgi contain enzymes for digesting pathogens
What are the mitochondria responsible for?
cellular respiration
What is the evidence that mitochondria and chloroplasts are the result of endosymbiosis?
Lynn Margulis
- contain bacterial DNA and bacterial membranes
- contain bacterial 70S ribosomes
- Self Replicating (binary fission)
What is the Eukaryotic Cytoskeleton made up of?
Actin microfliaments and Microtubules
What are Pseudopods?
The Eukaryotic cytoskeleton is responsible for shape changes creating pseudopods
-used in phagocytosis and movement
What molecules are synthesized in the nucleus?
- DNA
- Messenger RNA
- Ribosomal RNA
What is the function of the rough endoplasmic reticulum (RER)?
Synthesize proteins that will be embedded in membrane or secreted
What are the characteristics of fungi? What are the types of fungi?
Fungi are unicellular yeasts and colonial molds
There are:
1) Saprobes: decomposers
2) Parasites: opportunists
What are molds? How are they produced? What are mycelium? What are hyphae?
Colonial Fungi
-produced from reproductive spores
Mycelium: visible colony surface growth
Hyphae: filamentous growth (spore structures)
What are yeasts?
Unicellular Fungi
-produced from asymmetrical mitosis called BUDDING
Strings of buds form PSEUDOHYPHAE giving yeasts a filamentous appearance
What are protists? What are the protist pathogens?
Eukaryotes belonging to kingdom protista
Algae: plant like and aquatic
-unicellular and autorophic (photosynthetic)
Protozoa: animal like and aquatic
-unicellular and heterotrophic (feeders)
What are Harmful Algal Blooms?
aka “red tide”
- caused by alage
- intoxication not infection
- release neurotoxin that is taken up by filter feeders like shellfish
- people eat shellfish and ingest the neurotoxin
What are the characteristics of protozoa?
found in fresh & marine waters, soil, plants and animals
- heterotrophic “feeders”
- use phagocytosis and vacuoles to eat
Have no Cell Walls
-contain ectoplasm outside and endoplasm
What is the life cycle of the protozoan?
Trophozoite - Vegetative (feeding) form
Encystment - due to poor growth conditions
Cyst - similar to endospore but not as resistant
Germination - better growth conditions
What are the different classifications of protozoa?
Ciliated (Ciliophora)
Flagellated (Mastigophora)
Amoeboid (Sarcodina)
Apicomplexan (Sporozoa)
What are multicellular parasites?
parasites that are acquired in microscopic form (eggs, larvae)
- parasite acquires nutrients from host
- grows and develops into multicellular animal
What are the types of multicellular parasites?
Helminthes (two types)
Roundworms (nematodes)
-hookworm enters thru foot, then bloodstream, then digestive tract
Flatworms (cestodes - tapeworm, trematode - fluke)
-ingested as eggs or larvae
Which microbe reproduces by budding?
yeast
Which microbial structure is most functionally similar to a protozoan cyst?
Bacterial endospore
