Fungal Cells Flashcards
What percentage of angiosperm plants form a mycorrhizal symbiosis with fungi?
95%
Name a group of fungi that are major killers of amphibians.
Chytrids
What are the two major growth forms of fungi?
- Yeasts
- Hyphae
Describe yeast cells.
- Unicellular
- Often rounded
Describe hyphal cells.
- Elongated
- Usually multicellular
What are dimorphic fungi?
Fungi that grow as yeasts and hyphae.
Name the fungus that uses dimorphism to increase its pathogenicity.
Candida albicans
What is required for fungal growth?
Delivery of vesicles to the growth region (bud or hyphal tip)
How are vesicles delivered to the growth region of the fungus?
Using ‘fungal motors’ along the cytoskeleton
Describe pseudohypha.
Yeast-like cells form a string, with no cell-cell communication.
How are hyphal cells separated?
By septa
How do:
a) Yeast cells grow?
b) Hyphal cells grow?
a) Yeast cells grow by isotrophic growth, known as ‘budding’.
b) Hyphal cells grow by polarised growth.
Describe isotrophic growth.
Exocytosis occurs at the same rate all round the cell.
Describe polarised growth.
Exocytosis is faster at one end of the cell.
What is the disadvantage of hyphal fungi?
If one cell dies, the whole hypha dies
What is different about the cytoskeleton of a yeast cell?
It has no microtubules, because it is smaller, so no need for long-range transport.
What are actin patches involved in?
Endocytosis
What is chitin synthase used for in fungal cells?
To make chitin, a component of fungal cell walls
How often to vesicles arrive at a tip containing chitin synthase?
1 vesicle per minute
What is the Spitzenkörper?
A structure found in hyphae which serves as a ‘vesicle supply centre’ and controls where next exocytosis goes.
Who discovered there Spitzenkörper?
Reinhardt
In what fungi are Woronin bodies found?
Ascomycetes
Describe the concept of Woronin bodies.
Damaged cells in a hypha are isolated by ‘plugs’ in the septa called Woronin bodies, preventing other cells in the hypha from dying
What are Woronin bodies derived from?
Peroxisomes
