Fungi- Lecture 3 Flashcards
What are eukaryotic microbes?
fungi, protists, algae and slime moulds
What does fungi contain?
cell walls
what do protists not contain?
no cell walls
What are fungi?
A Diverse group- based on morphology made up of
unicellular (yeasts)
multicellular (moulds) and are Chemoorganotrophic heterotrophs that are involved in decomposition of organic matter.
Where do fungi inhabit?
soil and water
How does fungi reproduce?
by spores in means of asexual and sexual stages
What are moulds?
Non-photosynthetic, plant-like organisms. They are multicellular, filamentous organisms with Rigid cell walls made of
Chitin and other CHO polymers
what is an important feature of moulds?
Hypha- “Tube” containing many different nuclei with shared cytoplasmic components. Hyphal mat enlarges to become visible mycelium and these mycelium can be vegetative and ariel mycelium
What is the vegetative mycelium?
extends into growth medium to extract nutrients.
What is the ariel mycelium?
seen above the surface of the growth medium and contains reproductive structures
Where are spores produced?
Within a sac called a sporangium. The spores within the sporangium are called sporangiospores.
What is fungal taxonomy based upon?
- Morphological characteristics
- Reproductive characteristics
- DNA sequences 18s rRNA gene
What are yeasts?
Belong to the Ascomycota subdiivision. They are
Unicellular
(filamentous stages possible but rarely observed) and larger than bacteria (x10) and normally round/oval.
Contain cell walls made of chitin or other sugar polymers.
Is yeast diploid or haploid?
Haploid
how is yeast produced?
In asexual reproduction by binary fission or “budding”.
What is an example of yeast?
Saccharomyces cerevisiae
Where is Candida albicans found?
thrush (filamentous phase causes damage)
Where is Cryptococcus neoformans
found?
infections of HIV patients
Where is Saccharomyces cerevisiae
found?
alcohol and carbon dioxide
What industries are fungi involved in?
ethanol
antibiotics
enzymes (washing powders etc.)
solvents
food flavours
Cholesterol-lowering drugs
fungi are the main organisms involved in what?
the decay of organic material and the recycling of essential elements (C, N, etc.)
yeast are good model organisms for what?
genetic manipulation
what fungi is an edible mushroom?
agaricus bisporus
what mould is edible?
Fusarium veneatum where the mycelium can be shaped to mimic meat
What problems can fungi cause in humans?
- grain infections
- rusts- garden plants
- dry rot- homes, barns
- human infections- thrush
- food spoilage- bread mould, mucor
What caused the irish potato famine?
Phytophthora infestans – it is
NOT a Fungus any more!!!!!!!!
OOMYCETE
How does fungi benefit man?
In food production, enzyme production, antibiotic production, natural symbionts and element recycling for C, N and S
What is Mycorrhizae?
A plant-fungus mutualism and the vast majority of plants (>90%) is mycorrhizal
What are lichens?
A symbiotic relationship of fungi and algae and often found in harsh tundra condictions
Where does chitin biosynthesis occur in?
fungi
What size is fungi nuclei?
very small with little repetitve DNA
What unique sterol do fungal cell membranes have?
ergosterol
What pathway is different in fungi compared to humans?
Lysine biosynthesis pathway- they make it and humans don’t
What are chemoorganotrophic heterotrophs?
An organism that gets its carbon from organic substrates for growth and development and gets its energy from the decomposition, also oxidation, of an organic compound
What is hypha?
one of the threads that make up the mycelium of a fungus
What are mycelium?
a network of fungal threads or hyphae
What are 2 examples of mould species and where are they found?
Penicillium digitatum- found in soil of citrus producing areas
Stachybotrys chartarum (black mould)- found in water damaged building etc
what are 2 fungal diseases?
ringworm and vaginal candidiasis
