fungi quiz

The study of fungi

Very important for breaking things down in the environment, such as the soil, or whatever needs degredation. They find the decaying matter and further the process, without it, our environment would be in dire straits.

Eukaryotes

• Molds – multicellular (green/white growth on bread, veggies, fruit)
• Yeasts – unicellular (don’t see it unless you have huge amts of growth like thrush infection in mouth w/ coat of white slime)

• They are normally harmless to humans.
• Fungi can be opportunistic pathogens (typically in someone who is immunocompromised)

Fungal membranes contain ergosterol (has very similar shape to cholesterol, one way to attack fungal organisms is to attack this specific steroid, although there is some cross reactivity with cholesterol.)

• Polysaccharides
• Mannan
• Glucan
• Chitin (most specific in terms of classifying a cell wall as fungal, used to differentiate from fungus and bacteria)

• Asexual reproduction:
• Through conidia (mainly molds)
• Involves mitotic division and budding (yeast use a lot of budding)
• Sexual reproduction:
• Involves spores - ascospores, zygospores, or basidiospores
• Big difference between endospores (bacteria) and reproductive spores (molds)

• Fungi use heterotrophic metabolism. They obtain carbon from decaying organic matter.
• Most are obligate aerobes but some are facultative anaerobes.

• Molds - multicellular
• Yeasts - unicellular

• The simplest form of growth is budding.
• Buds are called blastoconidia.
• They are seen in yeasts.

W/ binary fission, cells will be the same size, w/ budding, second cell will be a lot smaller. Bud will eventually get bigger and then break off but after it breaks off it will prob still be smaller than the parent cell, and sometimes might stick to parents cell connected by a canal. Eventually, it will become as big as the parent cell.

• Tube like extensions of cytoplasm
• Some have septae - cross walls.
• Seen in molds.
• Molds form aerial hyphae (like a flower, looks like tuffs of hair coming out a circular structure, hyphae shoots out of top of this structure and creates conidia or spores)
• Hyphae contain reproductive structures: spores and condia
• Hyphae have a wide variety of shapes and sizes.
• Their distinct morphology and development are used to identify fungi.

• When a fungi can grow in mold or yeast form.
• The yeast form requires environmental conditions similar to in vivo.
• Proper temperature (around 37 degree body temp)
• Increased nutrients
• The mold form requires: Ambient temperatures, Minimal nutrients

• Kingdom Fungi has 4 subgroups called divisions.
• Classification is based on:
• - Nature of the sexual spores
• - Septation of the hyphae