Fungi Flashcards
____yote?
Eukaryotes (membrane-bound nucleus and cellular components).
____troph?
Fungi are heterotrophs (require organic foodstuffs).
Moulds may be saprophytic (feed on dead or decaying organic substances).
___cellular?
Yeasts or fungi are UNICELLULAR.
Moulds or higher fungi are MULTICELLULAR.
Oxygen requirements?
Moulds are obligate aerobes (require oxygen, carry it aerobic respiration to produce energy).
Yeasts may be obligate aerobes (require oxygen) OR facultative anaerobes (can live with or without oxygen) and can use glucose in respiration.
- Aerobic respiration yields more energy than anaerobic respiration e.g. alcohol fermentation *
Difference between septate and aseptate?
Septate is the name for hyphae with septum (cross walls). They contain pores that allow movement of the cytoplasm, nutrients and other organelles aka cytoplasmic streaming.
Aseptate is the name for hyphae with no cross walls.
What feature do moulds possess?
Moulds possess hyphae, a mass of hyphae = mycelium.
Fungal hyphae have an outer cell wall and a hollow lumen, which contains the cytoplasm and organelles.
Describe vegetative hyphae.
Vegetative hyphae form mycelia and anchor the fungus in its substrate, allowing the fungus to obtain nutrients from the environment. This is the most common type of hyphae.
Describe reproductive hyphae.
Reproductive hyphae are often referred to as aerial hyphae, as they stick up in the air and form reproductive spores.
How do fungi digest decaying plant material?
Through exodigestion, secreting cellulolytic enzymes to break down cellulose and to access cellular components. Small molecules can be absorbed directly where as larger molecules must first be broken down by extracellular enzymes. The resulting nutrients are then distributed throughout the mycelium via cytoplasmic streaming.
pH requirements?
Acidophiles.
Temperature requirements?
Mesophiles.
Describe what “mycorrhizae” means.
Mycorrhizae is the mutualistic partnership between plant roots and fungi. Plants perform photosynthesis to produce carbohydrates, which they share with the fungi. Fungi enhance plant access to water and minerals by extending mycelium into the soil. This is a symbiotic relationship.
Example of fungi that affects the human body?
Malassezia, a type of yeast, feeds on fatty secretions released by the skin and can cause dandruff.
Example of an opportunistic pathogen?
Pneumocystis is a fungal pneumonia that usually has a commensal relationship with humans, often quietly residing in the lungs. However, in immunocompromised individuals, it can spread and cause an attack on the body. This makes it an opportunistic pathogen.
Example of a fungi you may find on a surface?
Stachybotrys Chartarum aka black toxic mould. It contains mycotoxins in its spores which is an immunosuppressive and can cause a range of symptoms such as respiratory issues, liver damage and mental impairment.
How do yeast reproduce?
Yeast reproduces asexually through budding, where a bud forms on a parent cell, causing the nucleus to divide and copy itself. The bud becomes a separate daughter cell, which can further divide, creating chains of cells. A bud scar forms on the parent cell’s surface, marking this asexual reproduction.
May also reproduce sexually though spore formation.
Moulds reproduce both asexually and sexually. How do they reproduce asexually?
Spore division - spores develop in a sporangium, where the cytoplasm divides to form sporangiospores. In penicillium mould, spores called conidia form in chains on aerial hyphae, not in a sac.
Moulds reproduce both asexually and sexually. How do they reproduce sexually?
A zygospore is formed between the hyphae of opposite mating types. The haploid nuclei from each fuse, forming a single, diploid nucleus.
Rough ER function?
Ribosomes on surface that are responsible for protein synthesis.
Translate mRNA into polypeptide chains, which enter the rough ER for folding and modification.
Smooth ER function?
Detoxifies harmful substances such as alcohol using enzymes.
Responsible for lipid synthesis.
Involved in cellular homeostasis.
Golgi apparatus function?
Packages and modifies proteins.
Mitochondria function?
Site of aerobic respiration, produces energy in the form of ATP.
Cell wall function?
Contains chitin, which provides structural support and protection.
Nucleus function?
Houses genetic material.
Plays key role in cellular division.
Aids protein synthesis.
What does a fungicide in paint do?
Provides a protective barrier between the wall and moist conditions, protecting it from growth spurred on by wet conditions primarily in bathrooms or kitchens.
Beneficial effects of fungi?
Used in medicine, e.g. penicillin (chrysogenum) is extracted from penicillium notatum.
Detrimental effects of fungi?
Trichophyton mould, causes ringworm and athletes foot.
