Fungi Flashcards
What are the four sub-types of fungi and how are they distinguishable
Ascomycota Basidomycota Zygomycota Chytridomycota Distinguishable by the characteristics of their reproductive structures
How can fungi have two different names?
Teleomorph: form of the fungus that produces sexual reproduction structures
Anamorph: asexual form of the fungus
Why are arbuscular mycorrhiza (AM) so important in the ecosystem?
AM are the main absorbing organ of many plants
What are septa?
In basiodomycetes and ascomycetes, hyphae are subdivided into compartments by crosswalls; septa. Septa limit damage to mycellium by making it possible to seal off damaged compartments
What is ergosterol
Ergosterol is in fungal plasma membranes which has many functions, comparable to cholesterol in human plasma membrane
How are nutrients taken up on agar?
Nutrient uptake is driven by the proton motive force (3 pH units, 200-300 mV) generated by ATPases through exctrusion of protons
What are the function of vacuoles in fungi
digestion of compounds, storing of metabolites, cations and regulate cytoplasmic pH and ion concentration.
What is hyphae and how does hyphae extend
Hyphae extend apically and branching, this produces a network of filaments called mycelium
How are nutrients taken up by hyphae when they are aerial
Evaporation of water at the tip if growing aerial hyphae generates a water flow, carrying nutrient to their tips
What is the storage zone of fungi
As hyphae grow, excess nutrients are stored in the storage zone, and deposited as glycogen deposits or lipid droplets. Some of these nutrients are then used to produce reproductive structures.
What is branching
Branching occurs when the nutrient supply exceeds what is required to sustain growth at tip (exponential growth)
What are haustoria and nematode traps
Haustoria are complex morphological structures which conduct plant cell invasion in pathogenesis and mutalism; mycorrhiza) Nematode traps which allow fungi to trap and consume nematodes (roundworms)
What is the absorption zone of fungi
The breakdown products of nutrients are absorbed and converted into biomass and increase length of hyphae
What are Blastocladiales
Saptrotrophs (living on plant or animal debris) in fresh water, mud or soil
What is dimorphism
When a fungi species change morphology, for example some mucorales can grow anaerobically and this is associated with a change from hyphal morphology to yeast morphology.
What is the importance of glomales?
Glomales form all vesicular abuscular mycorrhizas (VAMs) which are the main absorbing organs of these plants
How to detect rare species by PCR?
Firstly need to design primers that can be used to amplify parts of the species ribosomal RNA encoding genes, if you get a PCR product that indicates that its present, but also compare with sequences in online databases
What are primary and secondary metabolites
Primary metabolites are directly involved in the normal growth of cell (ethanol in yeast) and secondary metabolites aren’t directly involved in the normal growth (penicillin in penicillium)
What is the main difference between cellular and acellular amoeba?
In vegetative state cellular amoebae is in a haploid ameboid cell, in acellular amoebae it is a multinucleate diploid called a plasmodium. This plasmodium develops into a fruiting body which disperses spores.
Describe a biological process that has prevented the development of a vaccine against malaria.
Constantly changing surface proteins allows plasmodium to evade the immune response, plasmodium has 60 genes and only one is shown, which means the immune response is for that one but it has 59 which can evade the immune response.
What are hydrogenosomes
In neocallimastigales derived from mitochondria. If enough of the NADH generated in glycolysis is used (oxidized) to reduce molecules in anabolism, then it is not necessary to reduce all pyruvate in fermentation to restore NAD. Under these circumstances, the hydrogenosome can generate 4 ATP per glucose.
what do the regulatory proteins of saccharomyces cerevisae do
Three regulatory proteins encoded by s.cerevissae mating type locus can determine cell type by regulating the expression of other genes, allowing s.cerevisae to change its mating type.
