Lecture 4 Flashcards
What are the external structures of a eukaryotic cell?
flagella, cilia, capsules and slimes
What makes up the boundary of a eukaryotic cell?
the cell wall and the cytoplasmic membrane
What are the internal structures of eukaryotic cell?
cytoplasm, nucleus, organells, ribosomoes, cytoskeleton
What do flagella and cilia do?
move toward nutrients and positive stimuli and away from harmful substances and stimuli (taxis)
What eukaryotic cells have flagella and cilia?
cilia and flagella - protozoa, many algae, and a few fungal and animal cells
What are the differences between eukaryotic and prokaryotic flagella?
- eukaryotic flagellum is 10x thicker
- covered by an extension of the cell membrane
- a long, sheathed cylinder containing regularly spaced microtubules in a 9+2 arrangement
- whipping motion,requires ATP
- May be single or multiple; generally found at one pole of cell
What do glycocalyces do?
- Never as organized as prokaryotic capsules
- Helps anchor animal cells adhere to each other
- Strengthens cell surface
- Provides protection against dehydration
- Function in cell-to-cell recognition and communication
What cells microbes have a cell wall?
Fungi, algae, and plants have cell walls but no glycocalyx
What is the cell wall composed of in eukaryotic cells?
Composed of various polysaccharides
What is the cytoplasmic membrane?
- Phospholipid bilayer with embedded proteins
- sterols for rigidity to prevent lysis
- selectively permeable
What does the cytoplasmic membrane perform?
-Perform endocytosis (eating or getting rid of substances)
What is the nucleus composed of?
Phospholipid bilayer, nucleoulus, chromatin
What occurs in the nucleolus?
rna synthesis
What are chromatin?
DNA and histones, DNA packaged as chromatin to be compact and fit in cell, strengthen and protect DNA, allow for cell division, control expression of genes
What is ER?
Netlike arrangement of hollow tubules continuous with nuclear envelope
Two forms
Smooth endoplasmic reticulum (SER)
Rough endoplasmic reticulum (RER)
What is RER?
- Extension of outer layer of nuclear envelope
- transport materials from the nucleus to the cytoplasm and ultimately to the cell’s exterior
- ribosomes attached to surface
- proteins synthesized on the RER are transported into the lumen and held for packaging and transport
What is SER?
No ribosomes
nutrient processing and storage of molecules i.e. lipids (not proteins)
What is the golgi apparatus?
Site of protein modification and shipping
Consists of several flattened, disc-shaped sacs called cisternae
closely associated with the endoplasmic reticulum
What is natures assembly line?
A gene from the nucleus is transcribed (transcription) into RNA and moves through the nuclear pores to the rough endoplasmic reticulum
Ribosomes translate (translation) the RNA into proteins, deposited into the lumen and transported to the Golgi apparatus for modification and packaging into vesicles
What do lysosomes peroxisomes, vacuoles, and vesicales do?
Store and transfer chemicals within cells
May store nutrients in cell
What do mitochondria do?
generate ATP
What is the inner membrane of mito called?
cristae
Where are chloroplasts found?
algae and plant cells
what is the cytoskeleton composed of?
Composed of fibers such as actin, tubulin, intermediate filaments
What does the cytoskeleton do?
Anchors organelles, provides shape to cell and allows cell to change its shape (i.e. amoeba – movement, feeding), can be used to move RNA and vesicles in cell
What are the 3 forms of fungi?
Unicellular, colonial, and complex/multicellular
Who do primary pathogens affect?
anybody, including healthy people
Who do opportunistic pathogens affect?
attack persons who are already weakened in some way
What is mycoses?
infections caused by fungi
What is heterotrophic fungi?
acquire nutrients from a wide variety of organic substrates
What is saprobic fungi?
obtain nutrients from the remnants of dead plants and animals in soil or aquatic habitats
What is parasitic fungi?
grow on the bodies of living animals or plants, although very few require a living host
What does mycelium mean?
the woven, intertwining mass of hyphae that makes up the body or colony of a mold
What does septa mean?
cross walls found in most fungi that allow the flow of organelles and nutrients between adjacent compartments
What does non-septate mean?
hyphae consist of one, long, continuous cell
What are vegetative hyphae responsible for?
the visible mass of growth
Do protozoans need or don’t water?
must have water
What is the life cycle of helminths?
Complete life cycle includes the fertilized egg, larval, and adult stages
Adults derive nutrients and reproduce sexually in a host’s body
Nematodes: sexes are separate and different in appearance
Trematodes: sexes can be separate or hermaphroditic
Cestodes: generally hermaphroditic
