ch. 4 - eukaryotic cells + microorganisms Flashcards
1
Q
what are flagella?
A
- allow for motility
- microtubules slide past eachother creating whipping motion - requires energy
2
Q
what are cillia?
A
- similar to flagella but shorter + more numerous + all over surface
- FOUND IN : a single group of protozoa + certain animal cells
3
Q
what is the glycocalyx?
A
- outermost layer (made of polysaccharides)
functions:
- for protection
- adherence of cells to surfaces
- reception of signals from other cell + environment
4
Q
what is the cell wall?
A
fungi cell walls:
- rigid + provide structural support + shape
5
Q
what does the cytoplasmic membrane do?
A
- serves as a selectively permeable barrier
6
Q
what is the nucleus?
A
- site of eukaryotic DNA (linear chromosomes)
- separated from cytoplasm by nuclear envelope
7
Q
what is the nucleolus?
A
- found in the nucleoplasm
- site of RNA synthesis
8
Q
what is chromatin?
A
- made of DNA + histone proteins
- genetic material of the cell
9
Q
what is the endoplasmic reticulum?
A
two types: rough and smooth
- series of microscopic tunnels used in transport + storage
10
Q
what is the rough endoplasmic reticulum (RER)?
A
- allows for transport of materials from the nucleus to the cytoplasm
- ribosomes attached to membrane surface
- protein synthesized here - held for packaging + transport
11
Q
what is the smooth endoplasmic reticulum (SER)?
A
- closed tubular network without ribosomes
- nutrient processing
- storage of nonprotein macromolecules
- lipid synthesis
12
Q
what is the golgi apparatus?
A
- factory that turns amino acids into proteins
- site of protein modification + shipping = sends things out of the cell
13
Q
what are lysosomes?
A
- participate in the removal of cell debris + damaged tissue
- contain: variety of enzymes involved in intracellular digestion of food particles + protection against invading microorganisms
14
Q
what are vacuoles?
A
- membrane bound sacs containing fluids or solid particles to be digested, excreted or stored
15
Q
what is the mitochondria?
A
- generate energy for the cell
- takes chemicals turns them into ATP
- located in cytoplasm, divide independently of the cell, contain circular strands of DNA, prokaryotic-sized 70s ribosomes
16
Q
what are the chloroplasts?
A
- capable of converting energy from sunlight into chemical energy through photosynthesis –> producing O2 as byproduct
17
Q
what are ribosomes?
A
- staging areas for protein synthesis
- scattered freely in cytoplasm + cytoskeleton
- intimately associated w/ RER
- 80S, combination of 60S + 40S subunits
18
Q
what is the cytoskeleton?
A
- flexible framework of molecules crisscrossing the cytoplasm
functions:
- anchoring organelles
- moving RNA + vesicles
- permitting shape changes
- movement
19
Q
what are the three types of filaments in the cytoskeleton?
A
- actin filament
- microtubules
- intermediate tubules
20
Q
what do actin filaments do in the cytoskeleton?
A
- cellular movement - contraction, crawling, pinching, + formation of cellular extensions
- long, thin protein strands
- throughout cell, mainly just inside the cell membrane
21
Q
what do microtubules do in the cytoskeleton?
A
- transport substances from one part of the cell to another
- spindle fibers play a role in mitosis
- maintain shape - eukaryotic cells
- long hollow tubes
22
Q
what do intermediate filaments do in the cytoskeleton?
A
- rope-like structures
- structural support for cell + organelles
23
Q
what are the two types of fungi?
A
- yeasts
- molds (mycellium)
- 100,000 species
24
Q
what forms do fungi come in?
A
- unicellular
- colonies
- complex/ multicellular (mushrooms/puffballs)
25
aspects of yeast?
- round to oval shape
- asexual reproduction
- budding
26
what are hyphae?
- long, threadlike cells found in the bodies of filamentous fungi
- pseudohypha: chain of yeast cells
27
what is mycellium?
- the woven, intertwining mass of hyphae that makes up the body or colony of mold
28
what is septa?
- segments found in most fungi
- allow flow of organelles + nutrients between adjacent compartments
29
what are non-septa hyphae?
- consists of one, long continuous cell
30
what is vegetative hyphae?
- responsible for the visible mass of growth
31
what are reproductive or fertile hyphae?
- produces spores
32
what are primary pathogens?
- can sicken even healthy persons
33
what are opportunistic pathogens?
- attack persons who are already weakened
ex.) HIV/AIDS patients often die of fungal infections against which healthy patients are immune
34
what is mycoses?
- fungal infections
- vary in the way the pathogen enters the body + the degree of tissue involvement
35
what are other harmful effects caused by fungi?
- fungal cells walls give off substances - cause allergies
- toxins produced by poisonous mushrooms cause death
- aspergillus flavus produces a potentially lethal poison - on grain
36
what are beneficial functions of fungi?
- play essential role in decomposing organic matter
- mycorrhizae --> formed stable associations w/ plant roots + increase ability to absorb water and nutrients
37
what does heterotrophic mean?
- to acquire nutrients from a wide variety of organic substrates
38
what does saprobic mean?
- to obtain nutrients from the remnants of dead plants + animals
39
what does parasitic mean?
- to grow on the bodies of living animals or plants
40
in fungus, what are spores for?
- reproduction
41
what are the two types of asexual spore formations?
- sporangiospores
- conidiospores
42
what are spongiospores?
- formed by successive cleavages within a sac-like head called **sporangium** attached to the stalk ** sporangiophore**
43
what are conidiospores?
- free spores not enclosed by spore-bearing sac
44
what is sexual spore formation?
- linking of genes from two parent fungi creating offspring with combinations of genes, different from that of the parent
45
what are protozoa?
- single celled aquatic eukaryotes
- most are harmless, free-living inhabitants of water + soil
ex.) malaria
46
what are the ways that eukaryotes can move?
- flagella - whip like motion
- cilia - sliding motion
- pseudopods - lurching motion
47
what is a cyst?
- protozoa can convert to this resistant, dormant stage when in a bad environment
- resistant to heat, drying, + chemicals
48
what is a trophozoite?
- motile feeding stage requiring ample food and moisture to stay active
49
what are helminths?
- tapeworms, flukes, + roundworms
- adult specimens - can typically be seen by the naked eye
50
what are flat worms?
phylum platyhelminthes
- thin, segmented body plan
- divides into cestodes (tapeworms) and trematodes (flukes)
51
what are roundworms?
phylum aschelminthes
- also called nematodes
- elongated, cylindrical, unsegmented body
52
example of helminth?
pin worm - enterobius vermicularis
- nematode - 2 to 12 mm long
- tapered, curved cylindrical shape
- easily treatable
