Microbiology Lecture 1 Flashcards
1
Q
microbes
A
- minute creatures
- less than 1/2 a mm in size
- not visible to naked eye
2
Q
ubiquitous
A
they are everywhere
- microbes
- they are in air, water, soil, inside us
3
Q
normal flora
A
- under normal conditions
- found in the gastrointestinal tract, genitourinary tract, respiratory tract, skin
- made up of microbes that are found in our bodies under normal conditions
4
Q
benefits of microbes
A
- protect us from disease by suppressing growth of pathogens (normal flora)
- pathogens do not get enough nutrients bc nutrients are being used up by the normal flora
- E. coli in large intestine makes vitamin K used for blood clotting (part of normal flora)
5
Q
microbes in aquatic environments
A
- filled with unicellular algae (bottom of food chain)
- food chain ex. unicellular algae > tiny fish > large fish > sharks
- all the organisms depend on unicellular algae
6
Q
unicellular algae
A
- bottom of food chain
- live in aquatic environment
- autotrophs (use CO2 and water to make sugar and release O2 (Photosynthesis)
- 80% of O2 is from unicellular algae
7
Q
soil microbes
A
- loaded with microbes
- recycle chemical elements
- decompose dead animals and plants
- breakdown cellulose and release CO2
- broken down cellulose is used by other plants
8
Q
microbes in food
A
- used to make things like
- yogurt
- cheese
- bread
- yeast + flour = dough
9
Q
rising dough
A
- yeast breaks down sugar in dough to release CO2 -> bubbles get trapped and cause expansion
- causes dough to rise
10
Q
therapeutic substances
A
- genetic engineering is used to force E. coli to make human insulin
- utilizing microbes
11
Q
bioremediation
A
-microbe are used to clean up chemical pollutants (oil spills) in the environment
12
Q
insecticide
A
- BT toxin is sprayed on plants (utilize microbes)
- kills insects
13
Q
sewage treatment
A
breakdown organic matter to produce methane
14
Q
harmful aspects of microbes
A
- cause disease like tuberculosis & lyme disease
- cause spoilage of food products (microbes break down sugar (lactose) and release acids)
15
Q
history of microbiology
A
- 1665- Robert hooke- plant materials (leaves and stems) little boxes called cells (not microbes)
- 1673-1723- anton van leeuwenhoek observe microbes under the microscope
16
Q
Anton Van Leeuwenhoek
A
- used rain water, scraping from his teeth to observe
- he saw microbe animalcules (different shapes floating around)
- circular, rod, spiral
17
Q
spontaneous generation theory
A
- life could arise from nonliving matter
- ex. decaying meat can give birth to maggots
18
Q
Francesco Redi
A
- tried to disprove spontaneous generation theory
- he put decaying meat in open and closed jars
- the closed jars didnt have maggots while the open had maggots
- repeats experiment with fresh air
19
Q
John Needham
A
- heated broth and poured into containers -> few days later -> microbes were found in broth
- people believed the broth gave birth to the microbes but the air born microbes contaminated broth
20
Q
spallanzani
A
- poured broth and sealed the containers -> then he heat it up -> this killed all the microbes after it was sealed
- no microbes arose
21
Q
theory of biogenesis
A
- rudolph virchow
- life could arise only from pre-existing living cells
22
Q
Disproving spontaneous generation theory
A
- louis pasteur- father of microbiology
- 1861
- took a flask with a long neck and added broth -> bent the neck of the flask into an S shaped curve leaving the flask open (fresh air) -> heat broth -> microbes did not show up
- microbes got stuck in the curve of the neck like a filter
- successfully disproves the spontaneous generation theory
23
Q
louis pasteur discoveries
A
- father of microbiology due to proving the spontaneous generation theory wrong
- microbes are ubiquitous
- foundation for the aseptic procedure used in the lab to prevent contamination
- fermentation -> yeast converted sugars to alcohol and CO2 in absence of O2
- pasteurization -> beverages such as milk are heated enough to kill microbes without destroying the flavor (doesnt kill ALL microbes) -> prevents diseases from spreading from food
24
Q
germ theory of disease
A
- belief microbes could cause diseases
- once fermentation was discovered they realized microbes cause changes in the body -> disease
- 1860s- Joseph lister treated surgical wounds with disinfectant
- 1876- robert koch proved germ theory of disease
- animals were dying of disease
25
Q
Robert Koch- Germ theory of disease
A
- drew blood from animals that died of disease
- isolated rod shaped bacterium (isolate #1)
- grew that bacteria in lab and obtained pure culture of bacterium
- injected bacterium into healthy animals
- healthy animals soon became sick and died
- isolated rod shaped bacteria in these animals (isolate #2)
- isolate #2 came from experimental animals while #1 came from nature
- isolates were identical proving that is was the cause of the disease
- bacterium was identified to be bacillus anthracis (anthrax)
- steps are known as Kochs postulates - identifies the determinant of a disease
26
Q
Kochs postulates
A
- used to determine causative agent of mysterious infectious disease
- isolates bacterium from animals sick in nature
- injects into health animals
- compare the isolates
27
Q
penicillin
A
- toxic to bacteria but not human cells
- 1928- alexander fleming
28
Q
naming organisms
A
- 1735- carolus linnaeus
- genus and species
- latin
- binomial
- describes the organism or honors a scientist
- underlined or italiced
- capitalize the genus and not the genus
29
Q
Staphylococcus aureus
A
- part of the normal flora of the skin
- genus- Staphylococcus (staphylo-cluster, coccus- circular)
- species- aureus (golden brown)
- exists in golden brown circular clusters
30
Q
Escherichia coli
A
- E. coli
- genus- Escherichia (honors the scientist)
- species- coli
- normal flora in large intestine
- not all E. coli is good (producing vitamins) -> some are pathogens
31
Q
diversity of microorganisms
A
- bacteria- prokaryotic
- pre-nucleus- DNA is NOT surrounded by a membrane (no nucleus)
- unicellular
- heterotroph- get energy from organic molecules
- cells walls made of peptidoglycan
32
Q
fungi
A
yeasts and molds
- eukaryotic
- unicellular/multicellular (most multi)
- ALL are heterotrophs
- cells walls are made of chitin
33
Q
eukaryotic
A
true nucleus
34
Q
protozoa
A
- eukaryotic
- unicellular
- heterotrophs
35
Q
algae
A
- eukaryotic
- unicellular/multicellular
- ALL autotrophs- photosynthesize
36
Q
virus
A
- acellular
- not made up of cells (no plasma membrane, no organelles, no cytoplasm)
- they do have DNA or RNA
- obligate intracellular parasites (need a host cell to reproduce)
37
Q
helminths
A
- worms
- multicellular
- they are not microscopic but their eggs are
- eggs can be observed under a microscope in spit when a person is infected
38
Q
classification of organisms
A
- 1969-robert whittaker classifies organisms
- 5 kingdom system
- based on:
- cell type- prokaryotic/eukaryotic
- cellular organization- unicellular/multicellular
- nutritional requirements- photosynthetic/nonphotosynthetic
39
Q
5 kindgoms
A
- prokaryotae (monera)- prokaryotic ex. bacteria
- protista- protozoa ex. ameba
- fungi- yeasts and molds
- plant- ferns, trees, flowering plants
- animal- worms, insects, vertebrates
40
Q
3 domains
A
- based on ribosomal RNA sequence
- archaea, bacteria, eukarya
41
Q
archaea
A
- prokaryotic
- unusual -> extreme environments
- salt lakes
- dead sea
- do not have peptidoglycan cell wall
- cell walls are made of pseudomurein
42
Q
bacteria domain
A
- prokaryotic
- normal flora
- pathogens
- most organisms have peptidoglycan cell walls
43
Q
eukarya domain
A
- all the eukaryotic organisms
- protozoa
- fungi
- plants
- animals
44
Q
measurement of microbes
A
- units- micrometers
- 1000micrometers=1mm
- length of bacteria- 2 um to 7 um
- diameter of bacteria- .2um to 2 um
45
Q
bright field microscope
A
- common
- field is bright (background)
- cells are darker than the background
- stain the cells (may cause damage)
- aka- compound microscope
- object is magnified by two separate lenses -> ocular and objective
- total magnification
- resolving power is .2um
46
Q
total magnification
A
magnification by the objective lens X magnification by the ocular lens (10x)
47
Q
resolving power
A
- resolution
- clarity/sharpness of image
48
Q
oil immersion
A
- improves the resolving power
- 100x lens aka oil immersion objective lens
- add a drop of oil immersion on the slide before 100x
- light bends away from the objective lens in the absence of oil immersion
- oil immersion causes most of the light to go through the objective lens
49
Q
dark field microscope
A
- cells are not stained
- if you do not want the cells to be damaged use this
- field is dark but object is bright
50
Q
Treponema pallidum
A
- spirochete
- causes syphilis
- destroyed by staining
- must use dark field microscope
51
Q
phase contrast microscope
A
- no staining
- used to see internal structures: organelles, endospores (bright oval structure)
52
Q
fluorescent microscope
A
- UV is light is used to illuminate the object
- cells are stained with fluorescent dyes
- Auramine O is used to stain Mycobacterium tuberculosis
- cells show up as glowing yellow objects against dark background
53
Q
electron microscope
A
- transmission electron microscope (TEM)
- scanning electron microscope (SEM)
- beam of electron is used in place of light
- cells are stained
54
Q
transmission electron microscope (TEM)
A
- thin sections of the specimen are obtained and placed on a copper mesh grid
- magnifies object 10,000X to 100,000X
- resolving power of .0025um
- used to observe internal structures
55
Q
scanning electron microscope (SEM)
A
- used to observe structures found on the surface of microbes ex. flagella
- magnifies the object 1000x to 10,000X
- resolving power or .02um
56
Q
staining
A
- dyes are salts
- used for bright field microscope
- positive and negative ions: either basic or acidic
- bacterial cell is negatively charged (its attracted to positive ion) -> ionic bond is formed between the cell and the stain
- therefore basic dyes are used to stain bacterial cells
57
Q
basic dye
A
positive ion has the color
- methylene blue chloride
- used to stain the cell
58
Q
acidic dye
A
- negative ion has the color
- sodium eosinate
- negative cells are repelled by negative ions -> this stains the background
59
Q
nigrosin
A
- acidic dye that is used
- negative ion has the color
- negative cell repels negative ion
- background is black and cells are bright (similar to dark field)
- negative staining
60
Q
simple staining
A
-basic dye is used to stain the cell to determine the shape and arrangement of cells
61
Q
gram staining
A
- differential staining technique that uses a primary stain and secondary counterstain to distinguish gram + or - bacteria
- places bacteria into 2 groups
- gram positive and negative
- most important staining bc it helps us identify unknown bacteria
- based on the cell wall structure of the bacterial cell
62
Q
negative staining
A
- uses an acidic dye
- negative ion has the color
- when an negative cell interacts with the acidic dye the background is dyed
- improves the contrast -> we can see the arrangement and shape of the cells
63
Q
gram positive
A
- do one set a biochemical tests on that bacteria to figure out the genus and species
- show up purple
- thick cell walls (peptidoglycan) -> helps hold on to the primary stain (crystal violet)
64
Q
gram negative
A
- do completely different set of chemical tests to identify the bacteria
- show up pink
- thin cell wall (only 1 or 2 layers of peptidoglycan)
- they have a outer membrane made up of lipids which is damaged by the alcohol used during gram staining -> causes primary stain to leak out and become colorless during gram staining acetone-alcohol step
65
Q
gram staining reagent
A
- crystal violet- primary stain
- iodine- mordant
- alcohol-acetone- decolorizer
- safranin- counterstain
66
Q
steps of gram staining
A
- first add crystal violet as a primary stain to bacterial specimen -> this stains both + and - cells purple or blue
- iodine, a mordant (strengthens the ionic bond btwn the bacterial cell and crystal violet), makes dye less soluble so it adheres to cell walls -> both + or - remain purple or blue
- acetone-alcohol (decolorizer) washed stain away from gram neg -> gram - cells become colorless while gram + remain purple or blue (differentiation step)
- Safranin (basic counterstain) allows dye adherance to gram-negative cells -> gram - cells turn pink while gram + remain purple or blue
67
Q
mordant
A
- strengthens the ionic bond between the bacterial cell and crystal violet
- iodine
68
Q
acid fast staining
A
- differential staining
- two genera are acid fast:
- myobacterium and nocardia
- they have waxy substance known as mycolic acid (complex lipid) in their cell walls
- acid fast staining is used to identify these two bacterium (used for tuberculosis)
69
Q
reagents for acid fast staining
A
- carbolfuchsin- primary stain
- acid-alcohol- decolorizer
- methylene blue- counterstain
- acid-fast= red
- nonacid-fast=blue
- both start out red due to primary stain -> decolorizer -> nonacid-fast loses color -> counterstain -> nonacid-fast turns blue -> acid-fast stays red
70
Q
capsule staining
A
- capsule is a gelatinous substance found around the cell wall
- cannot be stained
- not all bacteria has capsule
- stain the background using nigrosin
- stain the cell body with crystal violet
- background is black
- capsule shows up as a clear ring around the stained cell
- capsule is not being stained
71
Q
endospores
A
- 2 genera of bacteria that make endospores are bacillus and clostridium
- endospores are resistant to hostile environmental conditions (heat, UV light, disinfectant, desiccation)
- dormant stage of the cell
- endospores are formed within the vegetative cell (active cell)
- once formation is complete, endospores are released into environment
- vegetative cells make endospores when the environment lacks nutrients
72
Q
endospore staining
A
- malachite green- primary stain
- water- decolorizer
- safranin- counterstain
- endospores=green
- vegetative cells=pink
- both vegetative and endospores pick up primary stain -> both turn green -> water decolorizes vegetative cells -> vegetative cells pick up counterstain (safranin) and turn pink -> endospores remain green
73
Q
eukaryotic cell
A
-true nucleus
74
Q
organelle
A
specialized structure with specific function
75
Q
cilia
A
filamentous structures on the surface of the cell
- short and numerous
- on some eukaryotes
- if it has cilia there are many on the surface
- help cell move
76
Q
flagella
A
- filamentous structures
- long and few
- on some eukaryotes
- if it does have it is usually one or two
- help cell move
77
Q
cell walls
A
- plant cells have cullulose cell wall
- fungi have chitin cell wall
- animal cells have no cell wall
78
Q
glycocalyx
A
- sugar coat
- made up of cardohydrates
- found on surface of plasma membrane
- protects the cell
- animal cells have this
79
Q
plasma membrane
A
- proteins, lipids and carbohydrates
- encloses cytoplasm
80
Q
cytoplasm
A
-has cytoskeleton
81
Q
cytoskeleton
A
- made up of minute filaments that form a network within the cytoplasm
- microfilaments
- microtubules
- intermediate filaments
- involved in cytoplasmic streaming- cytoplasm circulates within the cell such that the nutrients are distributed throughout the cell
82
Q
cytoplasmic streaming
A
cytoplasm circulates within the cell such that the nutrients are distributed throughout the cell
83
Q
DNA
A
- within the nucleus
- chromatin is made up of DNA
- packaged into nucleosomes
- DNA is surrounded by the nuclear envelope (membrane)
84
Q
nuclear pores
A
- molecules move in and out of the nucleus through these
- DNA must be packaged into nucleosomes in order to move through
- holes in the nuclear envelope
85
Q
nucleolus
A
-ribosomal RNA is being synthesized here
86
Q
histones
A
- proteins
- segments of DNA are wrapped around histone proteins
- histone + DNA = nucleosome
87
Q
nucleosomes
A
- segments of DNA are wrapped around histone proteins
- these are packages
- move through the nuclear pores
- DNA + histone = nucleosome
88
Q
ER
A
- made up of flat membrane sacs
- make up network throughout cytoplasm
- rough- ribosomes are attached to the surface & proteins are synthesized
- smooth- no ribosomes attached- lipids are being synthesized
89
Q
ribosomes
A
- free in the cytoplasm
- show up as dots in a micrograph
- attached to rough ER
- made up of 2 subunits
- each subunit is made up of proteins and ribosomal RNA
- eukaryotic cells has 80s ribosome
- larger and denser than prokaryotic ribosomes (which is 70s)
90
Q
golgi complex
A
- made up of flat membrane sacs (4-6)
- proteins and lipids made in the ER are transported into the golgi complex
- modifies molecules
- transports molecules to other parts of the cell once they are modified
- ex. lipid is added to protein to make lipoprotein
91
Q
mitochondria
A
- cellular respiration
- makes ATP
- power house of the cell
- two membranes: outer (smooth) inner (folded)
- innermost (matrix)- has enzymes needed for kreb cycle, 70S ribosomes, & has DNA*
- folds: cristae
92
Q
cholorplast
A
- found in plant cells
- specialize in carrying out photosynthesis
- has chlorophyll- green pigment
- 2 membranes
- thylakoids- membrane sacs that have the chlorophyll
- has DNA and 70S ribosomes
93
Q
lysosomes
A
- membrane bound vesicles
- made up of membranes
- membrane bags filled with digestive enzymes
- white blood cells have a large # of lysosomes
- specialize in destroying microbes
94
Q
vacuole
A
- cavity surrounded by a membrane
- plant cells have large water vacuole
- when they are filled with water it makes the leaves and stems more rigid
95
Q
centriole
A
- cylindrical structure
- usually cell has 2
- made up of proteins
- associated with cell division
96
Q
helminths
A
- worms
- multicellular
- eukaryotic
- animal kingdom
- do not have a well developed nervous system or digestive system
- they do have a complex reproductive system
- platyhelminthes (flatworms) and nematodes (round worms)
97
Q
platyhelminthes
A
- trematodes (flukes)
- cestodes (tapeworms)
98
Q
trematodes
A
- flukes
- flat leaf like body
- hermaphroditic- both male and female reproductive organs (testes and ovaries)
- intermediate host- immature worm (larvae) lives here, asexual reproduction takes place here
- definitive host- mature worm (adult) lives here, sexual reproduction takes place here
99
Q
paragoniumus westermani
A
- lung fluke
- bronchioles of infected humans and other animals
- 12mm long
- lives for 4-5 years
- chest pain, cough
- treated with praziquantel
100
Q
life cycle of paragoniumus westermani (lung fluke)
A
- adult worm lives in lungs of infected humans (definitive host)
- eggs are released in the lungs
- eggs end up in the suptum and spit
- if it is swallowed the eggs end up in the feces
- if the eggs then end up in the water larvae will penetrate into a snail (intermediate host)
- larvae undergo asexual reproduction within the snail
- larvae exit the snail and enter creyfish (intermediate host) -> forms a cyst
- cyst has the resting baby worm -> if people eat this contaminated creyfish it will go into the human digestive tract and lungs
- cycle repeats
101
Q
cestodes
A
- intestinal parasites
- tape worms
- head- scolex
- scolex- has hooks an suckers -> help attachment to the host
- segmented body
- segments- proglottids
- hermaphroditic
102
Q
taenia saginata
A
- beef tapeworm
- can be as long as 18ft
- can live for 25 years
- adult- lives in intestinal tract of human (definitive host)
- eggs are released in feces
- cattle- ingest (intermediate host)
- larvae- cysts in the muscles (cysticerci) of cattle
- transmitted to humans when we eat undercooked contaminated beef
- intestinal tract- scolex comes out- develops into an adult worm
- repeat
- diagnosis- presence of eggs in feces
- symptoms- not much, abdominal discomfort
- treated with niclosamide
103
Q
taenia solium
A
- tapeworm
- adult- lives in infected humans (definitive host)
- eggs- found in feces
- ingested by pigs (intermediate host)
- larvae- cysts in the pigs muscles
- undercooked contaminated pork spreads to humans
- more dangerous bc humans can also become intermediate hosts -> *EGGS AND LARVAE ARE INFECTIOUS
- larvae cysts can form in humans in muscles, brain -> neurocysticercosis
104
Q
neurocysticercosis
A
- swiss cheese brain
- holes in the brain
- when taenia solium eggs develop into larvae and form cysts in the brain
- symptoms- headaches, convulsions, coma, death
- can occur with poor sanitary practices
- common in mexico, south america
105
Q
echinococcus granulosus
A
- tapeworm
- definitive host- dogs, coyotes
- eggs are released in feces
- can move to humans (or other animals) due to poor sanitary practices (intermediate host)
- larvae forms cysts in liver or lungs
- cysts are known as *hydatid cysts
- humans are a dead end to the life cycle of the worm -> humans are not eaten by other organisms (top of food chain) -> worm stays within human
- common in sheep herding population
106
Q
nematodes
A
- roundworms
- dioecious- male and female worms
107
Q
enterobious vermicularis
A
- pinworm
- nematode
- roundworm
- lives in intestinal tract of humans
- female worm migrates to anus and releases eggs in perianal area
- itching in the area
- eggs can end up in sheets, clothing, air -> spreads
- treated with mebendazole
108
Q
ascaris lumbricoides
A
- nematode, roundworm
- in small intestine
- feed on semidigested food
- eggs are released in feces
- larvae come out of eggs in intestinal tract and migrate to the lungs
- if there are too many larvae in the lungs they move back to the intestinal tract and become adult worms
- causes obstruction of the intestinal tract
109
Q
necator americanus
A
- lives in intestinal tract
- eggs are released in feces
- eggs are not infectious
- larvae come out in the soil
- larvae penetrate the skin (bottom of someones foot) and go into the intestinal tract
- attaches to the intestinal wall -> drink blood
- causes anemia
- prevented by wearing shoes
- common in south east
110
Q
trichinella spiralis
A
- undercooked encysted pork
- larvae come out in the intestinal tract when ingested
- female releases larvae -> worms dont release eggs they release larvae!
- larvae form cysts in the diaphragm muscles -> interferes with breathing
- pigs- get infested by eating contaminated pork or garbage
111
Q
protozoa
A
- unicellular- eukaryotic
- live in soil, water, within the bodies of humans and animals
- pathogenic protozoa exist in two stages
- trophozoites- metabolically active, produce, motile, inside the host
- cyst- metabolically inactive, dormant, outside the host
112
Q
entamoeba histolytica
A
- pseudopods
- ameba
- lives in intestinal tract
- cysts are released in the feces
- asymptomatic in the people who have cysts
- if the cysts are ingested trophozoites will be present in intestinal tract
- feed on cells lining the intestinal tract, red blood cells
- dysentery- bloody diarrhea
113
Q
pseudopods
A
- when the plasma membrane folds outward and make a finger like projection
- ameba uses this to crawl
- “fake feet”
114
Q
Giardia lamblia
A
- flagella
- tear drop shape
- 2 nuclei
- lives in intestinal tract- asymptomatic carriers
- cysts are released in the feces
- flagella in the cyst is inside the cell
- cysts are transfers through contaminated food and water
- when its ingested the trophozoites attach themselves to intestinal wall
- abdominal pain, diarrhea, **weight loss
- metronidazole- treatment drug
- common for wilderness water
115
Q
balantidium coli
A
- cilia for movement
- paramecium
- 2 nuclei
1. macronucleus- controls protein synthesis
2. micronucleus- transmits genetic information - cysts are transmitted in contaminated food or water
- trophozoites infect when they are ingested
- causes dysentery
116
Q
Paramecium
A
- nonpathogenic
- protozoa
- has cilia
- macronucleus
- micronucleus (not visable)
117
Q
hemoflagellates
A
- long, slender body
- undulating (wavy) membrane
- flagellum
- one nucleus
- no cyst phase only trophozoite
- ex. trypanoasoma gambiense
- causes african sleeping sickness
- transmitted by tsetse fly
- grows in bloodstream
- causes damage to the nervous system
- drowsiness, coma, death
118
Q
trypanosoma cruzi
A
- hemoflagellate
- transmitted by kissing bug
- bugs live in the crack of mud huts
- mexico, south america
- damages the nerves
- grows in the blood stream
- causes chagas disease
- causes mega colon, ega esophagus -> constipation
- flagellum
- blue dot on one end -> mitochondrial DNA
119
Q
Plasmodium
A
- pathogenic protozoa
- causes malaria
- transmitted by mosquito
- causes chills, fever, vomiting
- complex lifecycle
- chloroquine- treatment
- sexual reproduction takes place in mosquito- definitive host
- humans- intermediate host (asexual reproduction)
- life cycle:
1. sporozoite stage in salivary gland of the mosquito
2. sporozoites are released into the blood of person that is bit -> end up in liver
3. reproduce and become merozoites -> penetrate the RBC
3. ring stage grows and reproduces in RBC -> produces merozoites
4. RBC breaks down and merozoites are released in blood -> infect other RBC -> some merozoites differentiate into gametocytes (female and male)
5. when another mosquito bites this person the mosquito picks up the gametocytes
6. gametocyte goes into intentional tract of mosquito -> unite and form a zygote
7. zygote differentiates into sporozoite -> sporozoite migrate to salivary glands of mosquito
8. repeat
120
Q
mycology
A
- study of fungi
- myo- fungi
121
Q
fungi
A
- heterotrophs- need organic molecules for energy
- absorb nutrients
- make asexual spores
- sexually reproduce
- 2 types: yeast and molds
122
Q
yeast
A
- unicellular
- oval or circular in shape
- many reproduce by budding
- sometimes the buds fail to separate from the parent -> pseudohyphae are formed
- Candida albicans make pseudohyphae (part of the normal flora of intestinal tract of humans)
123
Q
molds
A
- multicellular
- filamentous
- filaments are called hyphae
- fragments of hypha can grow into a fungus
124
Q
hyphae
A
two types:
- septate hyphae- segmented by cross walls
- coenocytic hyphae- no segmentation
125
Q
dimorphic fungi
A
- grow mold-like @ 25C outside the body
- grow yeast-like @ 37C inside the body
126
Q
arthrospores
A
- septate hyphae becomes fragmented into single cells
- have thick cell walls
- Coccidioidea immitis makes arthrospores
127
Q
sporangiophore
A
- circular
- enclosed in a sac (sporangium)
- sac bursts and they are all released
- Rhizopus makes sporangiophores
128
Q
Conidiophore
A
- produced by penicillium
- formed in circular chains of conidia
- not enclosed in a sac
129
Q
sexual reproduction of reproduction
A
- two different strains (subspecies) need to be in the same area
- and - -> ex. Rhizopus + and Rhizopus - can mate
- strain makes pheromones- proteins while - doesnt
- attract negative strain with pheromones- mate -> negative strain grows towards the + due to pheromones
- and - fuse to make zygote
- zygote differentiates into a sexual spore
- depends on environmental conditions -> fungi makes sexual spores during nutrient depletion
- if the environment has nutrients they just make asexual spores
130
Q
3 groups of fungi
A
- based on sexual spores
- zygomycota
131
Q
zygomycota
A
- make asexual spores -> sporangiospores
- also make sexual spores -> zygospores
- they have coenocytic hyphae (not segmented)
- ex. rhizopus
132
Q
life cycle of rhizopus
A
-zygomycota
Asexual Reproduction
1. fungus grows and produced asexual spores (sporangiospores) in a sac (sporangium)
2. sac bursts and the sporangiospores are released
3. if sporangiospores end up in an environment that has nutrients they germinate -> grow into fungi
Sexual Reproduction
1. + and - strains come together -> zygote -> zygospore
2. if zygospore ends up in an environment that has nutrients it will germinate -> fungus
133
Q
Ascomycota
A
- some molds and some yeasts
- molds- septate hyphae
- molds produce asexual spore- conidiospores
- yeats reproduce by budding
- both yeast and molds produce sexual spores- ascopspores
- ex. Penicillium
134
Q
life cycle of penicillium
A
Asexual Reproduction
1. Produce conidiophore (asexual)
2. conidiophore released
3. if there are nutirents they germinate -> fungi
Sexual reproduction
1. + and - strains come together and from and zygote
2. zygote germinates into ascospores
3. ascospores are enclose in a sac (ascus)
4. sac bursts and ascospores are released
5. if there are nutrients they will germinate into fungus
135
Q
basidiomycota
A
- mushrooms
- septate hyphae
- asexual reproduce by fragmentation of hyphae
- fungi produce sexual spores- basidiospores
136
Q
life cycle of basidiomycota
A
Asexual Reproduction
1. fungus grows
2. piece of hyphae ends up in an environment with nutrients -> becomes fungus
Sexual Reproduction
1. + and - strains come together -> zygote
2. zygote grows into fruiting structure -> mushroom
3. basidiospores are formed and released
4. if there are nutrients the basidiospores will germinate -> fungi
137
Q
Mycoses
A
- fungal disease
- systemic mycoses- deep within the body
- caused by inhaling fungal spores
- starts in the lungs and spreads
- ex. histoplasmosis, coccidioidomycosis
138
Q
histoplasmosis
A
- minor respiratory infection
- if immune system is weak- spreads to liver, spleen bone marrow
- a type of systemic mycoses
- caused by histoplasma capsulatum
- a dimorphic fungus
- it produced conidiospore
- found in soil enriched with bird droppings
139
Q
coccidioidomycosis
A
- systemic mycoses
- caused by coccidiodes immitis
- arthrospores found in soil (southwest) cause this
- when it is inhaled it can be grow in the lungs
- cough, chest pain
- treated by amphotericin B
140
Q
cutaneous mycosis
A
- -affects the hair, nail, skin
- ringworm, tineas
- caused by the fungi- dermatophytes
- produce keratinase- breaks down keratin
- tinea pedia- atheletes foot:
- caused by trichophyton rubrum- itching, scaling skin
- spread by direct contact, shower room floors
141
Q
opportunistic mycosis
A
- ex. candidiasis
- caused by candida albicans
- part of the normal flora
- if your immune system is weak -> can cause thrush
- thrush- candida infection of the oral cavity
- common in people with AIDS, newborns
142
Q
amanita phalloides
A
- mushroom
- called death angel
- produces a neurotoxin
- causes hallucinations
- causes damage of the liver
- causes death within a week due to liver damage
143
Q
calviceps purpurea
A
- grows on grains- like rye
- a mold
- produces a toxin called ergot
- causes ergotism when ingested
- causes hallucinations
- causes constriction of the capillaries -> leads to gangrene
- common in the middle ages due to eating contaminated food
144
Q
dinoflagellates
A
- algae
- live in aquatic environments
- have two flagellum
- aka plankton- free floating
- many different species
- ex. Alexandrium- produces a neurotoxin
- mollusks (clams) eat dinoflagellates -> toxin is concentrated in the clams -> if people eat the clams they will get paralytic shellfish poisoning
- symptoms- numbness of mouth and lips (not serious)
- neurotoxin is heat stable (not destroyed by heat)
- condition is prevented by not collecting clams during red tide
145
Q
algae
A
- carryout photosynthesis
- eukaryotic
- live in aquatic environments
146
Q
diatoms
A
- algae
- photosynthesis
- in ponds, lakes, oceans
- common
- cell walls made up of silica
- bottom of food chain
