Lecture 15 and 16 Flashcards by Jim Jam

What do fungi membranes contain?

Sterol

How well did you know this?

Not at all

Perfectly

How many species of fungi are recorded?

More then 100,00 (estimated 1.5 million)

How well did you know this?

Not at all

Perfectly

What nutrient type are fungi?

Chemoheterotrophs

How well did you know this?

Not at all

Perfectly

How do fungi acquire food?

Absorptive (saprotrophic)

How well did you know this?

Not at all

Perfectly

What type of digestion do fungi have?

Extracellular digestion: produce and secrete enzymes that digest substrate

How well did you know this?

Not at all

Perfectly

How do fungi absorb digestion products?

Endocytosis, transporters

How well did you know this?

Not at all

Perfectly

Name a symbiotic relationship of fungi with plants.

Mycorrhizae (plants get minerals/phosphate, fungi get sugars/amino acids)

How well did you know this?

Not at all

Perfectly

What are the two type of mycorrhizae?

Endomycorrhizae (penetrates coritcal cells of root), ectomycorrhiza (surrounds root)

How well did you know this?

Not at all

Perfectly

What are lichens?

Green algae/cyanobacteria and fungi

How well did you know this?

Not at all

Perfectly

What can fungi act as pest control against?

Nematodes, weeds, mites, other fungi

How well did you know this?

Not at all

Perfectly

What is the break down and consumption of environmental pollutants called?

Bioremeidation

How well did you know this?

Not at all

Perfectly

Name an immunosupressive fungi

Cyclosporins

How well did you know this?

Not at all

Perfectly

How many pathogenic fungal species are there to animals and humans?

Around 200, most nosocomial and/or opportunistic

How well did you know this?

Not at all

Perfectly

Name an oppertunistic infection of fungi in AIDs patients.

Crytococcal meningitis

How well did you know this?

Not at all

Perfectly

Aspergillosis fungi can cause…

Pulmonary aspergillosis or invasive aspergillosis

How well did you know this?

Not at all

Perfectly

What toxic compounds do some fungi produce?

Mycotoxins, such as amatoxins

How well did you know this?

Not at all

Perfectly

What does Amanita phalloides (Death cap) produce?

Alpha-amanitin which inhibits RNA polymerase II

How well did you know this?

Not at all

Perfectly

Alfatoxin. flavus metabolites intercalates with DNA, which…

Damages DNA bases (alkylation) promotes oncogene mutations

How well did you know this?

Not at all

Perfectly

How does fungal cell wall protect underlying cytoplasm?

Provides stable osmotic environment

How well did you know this?

Not at all

Perfectly

What is chitin made of?

N-acetylglucosamine polymer, chains with beta 1-4 linkage

How well did you know this?

Not at all

Perfectly

Chitin function?

Cell wall stability

How well did you know this?

Not at all

Perfectly

What is a pollysaccharide of D-glucose found in cell wall?

glucans (50-60%)

How well did you know this?

Not at all

Perfectly

Linkages in most glucans?

beta 1-3 linked

How well did you know this?

Not at all

Perfectly

Glucan function?

Attachment site for other wall components

How well did you know this?

Not at all

Perfectly

Where are glycoproteins found in the cell wall?

Outer surface, interwoven over chitan/glucan layer

Function of glycoproteins?

Adhesion to surfaces, fusion of fungi, protection, molecule uptake, signal transduction, synthesis

Plasma membrane sterol is?

Ergosterol

What does ergosterol do?

Reduce membrane fluidity and permability

Antifungal drugs target what biosynthesis pathway?

Ergosterol

2 types of vegetative hyphae:

Septate hyphae | Coenocytic (aseptate) hyphae

What is growth at the tip of vegetative hyphae called?

Apical growth

Features of growing tip:

- Structure/function different - Denser cytoplasm - No major organelles

WHat does growing tip contain?

Spitzenkorper

What is spitzenkorper?

Structure where golgi-derived vesicles accumulate, which exocytosis

What do the spitzenkorper vesicles contain?

Enzymes involved in wall lysis, wall synnthesis, precursor wall polymers (mannoproteins)

Name when growing tips fork

Bifurcate

Vegetative hyphae can extend out of the substrate to form what?

Aerial hyphae

How do aerial hyphae produce asexual spores?

They undergo mitosis and subsequent cell division

What are the 2 types of asexual spore?

Conidiospores | Sporangiospores

What are conidiospores?

Spores produced in non-enclosed chains at the end of aerial hyphae

What are sporangiospores?

Spores produced in specialised cells at the end of aerial hyphae, remain enclosed in sporangium (sac) until mature

Asexual spores germinate to produce

hyphae

What are compatible mating fungi

- and + strains, which attract each other using chemicals

First stage of sexual reproduction in multicellular fungi

Plasmogamy

What is plasmogamy

Hyphae fuses, cytoplasm mixes, + haploid nucleus enters recipient cytoplasm

What are some plasmogamy exceptions?

Some fungi nuclei remain apart, develop dikaryotic mycelium, gives rise to fruiting body (mushroom, toadstool, cap)

What is the second step of multicellular fungi sexual reproduction?

Karyogamy

Where does karyogamy occur in fruiting bodies?

Gills

What is karyogamy?

- and + nuclei fuse to form diploid zygote nucleus

What is the third phase of sexual reproduction in multicellular fungi?

Meiosis

How many unicellular fungi (yeast) species have been described?

around 1500

How do most yeasts divide?

Budding

Give an example of a budding yeast

Saccharomyces cerevisiae

Stages of budding

Protuberance (bud) forms on surface of parent cell Bud elongates Nuclei/organelles divide Cell wall material laid down between parent and bud

How many times can a yeast bud?

Up to 24 times

What forms when incomplete buds remain attached to parent?

Psyedohyphae

Name a yeast that divides by binary fission

Schizosaccharomyces pombe

Stages of binary fission in yeast.

Parental cell elongates Nuclei/orgalles divide Segregation of nuclei and organelles Cytokinesis

Name a dimorphic fungi that is goverened by CO2

Mucor indicus (In algae, mold like, on agar, yeast like)

Name a dimorphic fungi governed by temperature

Histoplasma capsulatum (yeast at 37, mold when lower)

What does Histoplasma capsulatum cause?

Histoplasmosis (TB like infection in lower respiratory tract)

Fungal infections are called

Mycosis

5 groups of fungal disease

``` Systemic mycoses Subcutaneous mycoses Superficial mycoses Cutaneous mycoses Opportunistic mycoses ```

Systemic mycoses caused by and transmission by

Soil fungi | Spore inhalation

Name a systemic mycoses

Histoplasmosis caused by Histoplasma capsulatum

What causes and what is the route of transmission of subcutaneous mycoses?

Saprophytic soil fungi | Spores/hyphae in wound

Name a disease and fungi associated with subcutaneous mycoses

Sporotichosis caused by Sporothrix schenkii

What do cutaneous mycoses secrete?

Keratinase (degrades keratin)

Example of cutaneous mycoses

Ringworm (trichophyton species) | Atheletes foot

What drugs inhibit Beta (1-3) glucan synthase?

Echinocandins (fungicidal against yeast, fungistatic against molds)

What drugs bind ergosterol?

Polyenes

What drugs inhibit ergosterol biosynthesis?

Imidazole

Name another class of drug that is exploits fungal plasma membranes.

Triazole

How many species of protozoa?

20,000

How do protozoa digest food?

In food vacuole

How do protozoa eliminate waste?

Plasma membrane or anal pore

Amoeba contain:

Endoplasm (central) | Ectoplasm (clear)

Protozoa cilia and flagella are also called...

Undulipodia

Undulipodia consist of:

Basal body, axoneme (9+2 arrangement), plasma membrane

Trypanosome, leishmania have how many flagellum?

What protozoa have multiple flagella?

Giardia, trichomonas

Name protozoa that uses cilia for feeding and swimming

Paramecium

Archaezoa features:

``` Lack mitochondria Some contain hydrogenosome/mitosome Symbionts in digestive tract Anaerobic 2 or more flagella form cysts ```

What is the causative agent of giardiasis?

Giardia lamblia

How does giardiasis spread?

Fecal/oral, anthroponotic and zoonotic

What is the causative agent of Trichomoniasis?

Trichomonas vaginalis

How does Trichomoniasis spread?

Sexually (hot tubs, wet bathing suits/towels/washcloths)

How does T.vaginalis attach to surfaces?

Axostyle

T.vaginalis features

No cyst stage | Can survive 24hrs outside host

What amoebozoa causes amoebic dysentry/amoebic liver abscesses?

Entamoeba histolytica

Plasmodium that causes malaria is what type of protozoa?

Apicomplexa

Number of deaths each year from malaria

0.6 million

Most common species that causes malaria.

P.vivax

Most deadly malaria species

P.falciparum

Name two more apicomplexa diseases

Cryptosporidiosis | Toxoplasmosis (spread through cat shit)

Name the group of protozoa with unusual organelles.

Euglenozoa

Name a disease and its bacteria caused by euglenozoa

Trypanosoma brucei causes African Trypanosomiasis

What transmits african trypanosomiasis?

tsetse fly