Micro 5- Fungi Flashcards
what do chemoheterotrophs do?
decompose organic matter
eukaryotic fungi have what in their cell walls
chitin
what is present in fungi cell membrane that isn’t present in bacteria
sterols
what type of metabolism is fungi limited to
heterotrophic, aerobic, facultatively anaerobic
what is the thallus and what does it consist of
it is the body of the fungus and consists of hyphae filaments
a mass of hyphae is called a
mycelium
septate hyphae vs. coenocytic hyphae
septate- contains cross-walls
coenocytic- does not contain septa
vegitative vs. aerial hyphae
vegitative hyphae obtain nutrients while aerial hyphae are involved with reproduction
main properties of yeasts
- nonfilamentous and unicellular
- typically spherical or oval
budding yeasts vs. fission yeasts
budding yeasts divide unevenly
fission yeasts divide evenly and produce a colony on solid medium
example of budding yeasts and fission yeasts
- budding- candida albicans
- fission- schizosaccharomyces
what is dimorphic fungi and what are the conditions for each type
two forms of growth, can grow as a mold or a yeast
- yeast-like at 37, in body, more nutrients, reproduce by budding
- mold-like at 25, in environment, fewer nutrients, produce vegetative and aerial hyphae
explain the fungi life cycle
fungi reproduce sexually and asexually via the formation of spore that detach from the parent and germinate into a new mold
asexual spores are produced via
mitosis and cell division, formed by the hyphae of one organism
-both conidiospore and sporangiospore
conidiospore vs. sporangiospore
both asexual spores
conidiospore is not enclosed in a sac
sporangiospore is enclosed in a sac
sexual spores occur from the
fusion of nuclei from two opposite mating strands
list 3 phases of sexual spores
- plasmogamy
- karyogamy
- meiosis
sexual spores sexual reproduction step 1
plasmogamy
haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (-)
sexual spores sexual reproduction step 2
karyogamy
+ and - nuclei fuse and form diploid zygote
sexual spores sexual reproduction step 3
meiosis
diploid nucleus produces haploid nuclei (sexual spores)
nutritional adaptations of fungi
- grow better at pH of 5
- grow in high sugar and salt concentration, resistant to osmotic pressure
- can grow in low moisture content
- can metabolize complex carbohydrates
mycosis
fungal infection
list of types of mycoses
- systemic
- subcutaneous
- cutaneous
- superficial
- opportunistic
systemic mycoses
- deep within the body
- caused by fungi that live in soil
- spores transmitted by inhalation
- infections begin in lungs and then spread to other body tissues
examples of systemic mycoses
- histoplasmosis (lower respiratory infection, similar to TB)
- coccidioidomycosis (valley fever, San Joaquin, in soil)
subcutaneous mycoses
- beneath the skin
- caused by fungi that live in soil and on vegetation
- forms small ulcers on hands
- occurs by direct implantation of spores or mycelial fragments into a puncture wound in the skin
example of subcutaneous mycoses
sporotrichosis- acquired by gardeners and farmers
cutaneous mycoses
also called dermatomycoses
- affect hair, epidermis, and nails
- caused by dermatophytes that secrete keratinous
- transmitted by direct contact or contact with infected hairs and epidermal cells
examples of cutaneous mycoses
-tineas or ringworm (tinea barbae)
tinea pedis, athletes foot
opportunistic mycoses
-fungi harmless in normal habitat but pathogenic in a compromised host
list of 3 types of opportunistic mycoses
- pneumocystis
- mucormycosis
- aspergillosis
pneumocystis
opportunistic mycoses
-most common life-threatening infection in AIDS patients
mucormycosis
opportunistic mycoses
-in patients with diabetes mellitus, leukemia or under treatment with immunosuppressive drugs
aspergillosis
opportunistic mycoses
-in patients with debilitating lung diseases or cancer
superficial mycoses
- localized along hair shafts and in superficial (surface) epidermal cells
- prevalent in tropical climates
yeast infections, candidiasis
- candida albicans most frequent
- from pseudohyphae, resistant to phagocytosis