Fungi Flashcards
What kind of energy classification is fungi?
heterotrophs - They secrete digestive enzymes and then absorb the soluble products of digestion.
Energy is stored in the form of glycogen
Is fungi prokaryotic or eukaryotic?
eukaryotic
hyphae
fungi are composed of filaments called hyphae
mycelium
multiple hyphae
Do fungi reproduce sexually or asexually?
Both - The haploid state is predominant, but they do alternate between a haploid and diploid state.
Depending on conditions like dampness, food availability, and temperature they will produce sexual spores, asexual spores or sometimes both simultaneously
Saprophytic
Fungi are saprophytic, they break down the remains of living organisms that have died
Fungi
- Eukaryotic
- mostly Multi-cellular
- immotile
- Have cell walls
- Use glycogen for energy
- Heterotrophic
- More similar to human cells than bacteria
- Can attack living or dead organic matter
- Always rely on extracellular digestion and absorption
- Cell wall made up of chitin
- produces spores
saprobes
Get nutrients from nonliving organic matter, such as dead animals, and waste of living organisms
parasites
Get nutrients from host tissue
Fungi include?
- Mushrooms
- Toadstools
- yeasts
- Molds (rhizopus stolinifer - bread mold)
- Mildew
What is a lichen?
Lichen is a mutualistic association of
- a fungus and cyanobacteria
or
- a fungus and photosynthetic algae
Often live on bare rock and is seen abundantly in the arctic tundra, where reindeer survive on them
- example of mutualism
Major groups of Fungi
- Ascomycetes “Sac Fungi”
- Zygomycetes
- oomycetes (water molds)
NB: just know that mycetes means fungi
Asexual fungi reproduction
Spores
- The spore is a haploid cell resulting from mitosis of another haploid cell.
- Spores are distributed through wind, water, or through other organisms
- If conditions are right, a new hyphae will form
Budding
- Yeast do not make spores. They are unicellular. They pinch off from the parent cell in a mitotic process called budding
Fungi Sexual reproduction
- Mating between haploid hyphae occurs
- The hyphae of adjacent fungi grow toward each other and then form a bridge between two hyphae cells of different genetic makeup
- The nuclei of the two cells fuse to form a 2n diploid spore called a zygospore.
- The zygospore contains a sac called a sporangium where meiosis occurs.
- The zygospore can divide via Meiosis to create new haploid spores with different genetic makeup from the parents
sporangium
A sac in the zygospore where meiosis of the 2n cell can occur, resulting in two haploid daughter spore cells
zygospore
The fusion of two hyphae of different genetic makeup
What is Mycorrhizae?
An example of mutualism (symbiosis)
A combination of fungus and the root of a plant. The fungus helps the plant get the nutrients it needs, and the fungus gets nutrients in turn.
What is the difference between the bacterial and fungal cell wall?
The fungal cell wall is made up of chitin and the bacterial cell wall is made up of peptidoglycan
What’s the difference between a glycoprotein and peptidoglycan? (not related to fungi, just needed to capture this question)
Glycoprotein is a protein with a carbohydrate group added to it.
peptidoglycan is the structure of a bacterial cell wall
Antifungal drugs target what?
The chitinous cell wall of fungus. Since humans and bacteria don’t have chitin in our membranes or cell walls we can use anti-fungal drugs without worrying about hurting our cells.
Fungal cell membranes can also be targeted, since they have significant differences from our own
What is the difference between syncytium and coenocytes?
Syncytium results from the fusion of multiple unicellular cells to form a multi-nucleated cell. It can also refer to cells connected together via gap junctions.
Coenocytes are multi-nucleated cells formed from cells that undergo mitosis, but don’t undergo cytokinesis. Fungi hypha can be coenocytic not containing any septa.
Septa
A divider between cells in fungi hypha. The divider allows nuclei and organelles to pass freely from cell to cell.
Sometimes fungi don’t have septa, and instead undergo mitosis without cytokinesis. This results in hypha cells that could contain hundreds or thousands of nuclei
Haustoria
A specialized hypha cell in parasitic fungi that has special digestive enzymes. The haustoria can travel through the cell wall of the host and lie against the host’s cell membrane in order to absorb nutrients.
The haustoria continues to grow by breaking down the cell wall and increasing its surface area on the host membrane.
Fungi anti-bacterials
Penicilin was discovered from bread mold.
Penicilin has a structure called a beta lactam ring.
It disrupts the synthesis of the bacterial wall.
Bacterial resistance takes awhile to occur, but usually occurs from the formation of Beta-Lactamases which disrupt the beta lactam ring.
Many antibacterial drugs include a beta lactam ring including penicilin G, Penicillin V, ampicillin, and many more.
