Lecture 22: Fungi
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- fungus vs fungi
- one fungus, two fungi
- Is a Fungus Prokaryotic or Eukaryotic?
- Eukaryotic
- A fungus is _____-bearing
-
spore-bearing.
It can duplicate itself in spore gorm (genetically identical) - Fungus eat by absorbing nutrients. Most fungi are ______, heterotrophic organisms that feed on dead organic matter
- saprobes
- saprobes
- heterotrophic organisms that feed on dead organic matter
- What are three positive Roles of Fungi?
-
1) FUngi are decomposers
2) Industrial applications
3) Research - Fungi are decomposers. They release ______ back into the environment, make available to plants for recycling.
- carbon/minerals
- There are several industrial applications of fungus. Name 3.
-
1) Foods- cheese, bread, soy sauce
2) Drinks- beer, wine, sake
3) Antibiotics, insecticides, etc (ex. penicillin, cephalosporin) - Research. ________ for fundamental biological processes
- Ideal experimental system
- Fungi also play a negative role. THey cause diseases in ___, ____, and ____
-
plants (dutch elm disease)
animals (ring worm)
humans - It is difficult to cure fungal infections because both the _____ and ______ are eukaryotes
-
target
host
*all prokaryotes have something to target with a certain drug, but Fungi are eukaryotic, so harder to target with something specific, difficult to cure - What are the four main differences between Fungi and Plants?
-
1) Fungi have NO CHLOROPHYLL
2) Fungi have CHITIN
3) Fungi are NOT TRULY MULTICELLULAR
4) Fungi are HETEROTROPHIC eukaryotes - Chitin is a homopolymer of _____
-
N-acetyglucosamine
It is a structural polysaccharide
N-acetyglucosamine homopolymer is not found in plants - Fungi are either ____ or ____
-
yeasts
molds - Fungi are either yeasts or molds or both, some are ______
- biphasic/dimorphic
- Fungi can be biphasic/dimorphic, depending on ____
-
temperature
Mold-like phase at 25oC
Yeast-like phase at 37oC - A yeast is a ______ fungus with a single nucleus
- unicellular
- Molds are fungi with _____
-
hyphae
hyphae are long, branched filaments - Mold has ______, a thick mass of hyphae
- mycelium
- septate fungi
- individual cells are separated by cross-walls
- Give an example of a septate fungi
- penicillium notatum
- coenocytic fungi
- there are no septa
- Give an example of a coenocytic fungi
- Rhizopus stolonifer (bread mold)
- What has no septa?
- Coenocytic fungi
- septum vs septa vs septate
-
septum- one
septa- many
septate- describes fungus with septa - In asexual reproduction, the spores produced are ____
-
genetically identical to the parent
depending on structure spore comes from is how it is named - In sexual Reproduction, cells of ______ fuse
- opposite mating type
- In sexual reproduction, cells of opposite mating type fuse. _____ fuse, ____ mix. Cell is now diploid
- nuclei fuse, chromosomes mix
- In sexual reproduction, cells of opposite mating type fuse. Nuclei fuse, chromosomes mix. Cell is now diploid. Cell then undergoes _____ to return to haploid state.
- division
- In sexual reproduction, cells of opposite mating type fuse. Nuclei fuse, chromosomes mix. Cell is now diploid. Cell then undergoes division to return to haploid state. ____ then develop from cells in haploid state
-
spores
Ex:
MATa mates with MATb --> MATab diploid with mixed chromosomes --> divide --> disect out and get haploid - Give the name of bakers yeast
- Saccharomyces cerevisiae
- Give 5 classes of Fungi
-
1) Chytridiomycota
2) Zygomycota
3) Ascomycota
4) Basidiomycota
5) Deuteromycota - CHYTRIDIOMYCOTA. What are chytrids?
- group of aquatic fungi with flagellated spores
- Chytrids are ____ and like to kill amphibians
- parasitic
- ZYGOMYCOTA have what kind of hyphae?
- Coenocytic hyphae w/septa only where reproductive cells are formed
- ZYGOMYCOTA. In the mycelium, thousands of asexually produces ______ are being produceed within ______
-
sporangiospores
sporangium - Give an example of a zygomycota
- bread mold- Rhizopus stolonifer
- Give the formal name of the fungi that causes bread mold
-
rhizopus stolonifer
it is a zygomycota - Besides bread mold, Rhizopus can be found in what two things?
- sake, cortisone
- Ascomycota is a ___ fungi
- sac
- Ascomycota is a sac fungi. Its characteristic reproductive structure is a sac-like ____
- ascus
- What kind of hyphae is in the mycelium of ascomycota?
- septate
- Asexual reproduction of ascomycota leads to the formation of ______
- conidiospores
- Give three examples of ascomycota
-
unicellular yeast
cup fungi
truffles - Basidiomycota is commonly known as the ___
- mushroom
- What is the reproductive structure of basidiomycota?
- Basidium
- Basidium is the reproductive structure on which sexual spores are produced after _____
- hyphal fusion
- Give the name of the basidiomycota that looks good but kills, also known as the 'destroying angel'
- Amanita phalloides
- Amanita phalloides is always fatal and produces what two toxins?
-
phalloidin
alpha-amanitin - Phalloidin, produced by Amanita phalloides, a basidiomycota, targets what?
- liver
- Alpha-amanitin, produced by Amanita phalloides, a basidiomycota, targets what?
- GI tract
- deuteromycota are also known as ____
- fungi imperfecti
- Why are deuteromycota known as fungi imperfecti?
-
- no known sexual cycle
- varied types of asexual spores - Give two examples of deuteromycota that are human pathogens
-
1) Candida albicans - thrush in mouth
2) Histoplasma capsulatum - disease in lungs - Give an example of a deuteromycota that is helpful to humans
- penicillium
- What are the five groups of mycoses (fungal diseases) transmitted by inhalation of spores?
-
1) Subcutaneous
2) Cutaneous
3) Superficial
4) Opportunistic
5) Systemic - throughout the body, affects many tissues/organs - Subcutaneous- fungal infections caused by ____
- spores implanted in puncture wounds
- cutaneous- fungal infections of _____
- hair, nails, and skin
- Superficial- fungal infections on _____ or ____
- hair shafts or skin surface
- Give an example of a fungus that infects the hairshaft (superficial)
- black piedra
- Opportunistic. Give an example of a fungus that causes opportunistic mycoses
- Candida albicans
- What is another name for valley fever?
- Coccidioidomycosis
- What is the causing agent of valley fever?
- Coccidioides immitis
- What does Coccidioides immitis produce that can be inhaled?
- produces ARTHROSPORES that can be inhaled
- What are the symptoms of valley fever?
- respiratory infection, flu-like symptoms
- Coccidioides immitis produces arthrospores that are inhaled and then swell to yield _____
- spherules that cause inflammation
- Coccidioides immitis produces arthrospores that are inhaled and then swell to yield spherules that cause inflammation. Spherules pop and release _____ in human lungs
-
endospores
-may reinfect and start cycle over - Describe the developmental cycle of Coccidioides immitis
- Outside the body, the organism exists as a septate mycelium. It segments to form airborne arthrospores, which are inhaled. In the respiratory tract, the arthrospores swell to yield a large body, the spherule, that segments and breaks down to release endospores. When released to the environment, the endospores form germ tubes and then the mycelium.
- Coccidioidomycosis (valley fever) can become chronic, especially in ______. It is systemic.
- immunosupressed
- Dermatophytosis is a general name for a fungal disease of the ____, ____, and ___
- hair, skin, and nails
- Dermatophytosis is also known as _____
- tinea infections
- athlete's foot
- tinea pedis
- ringworm of the head
- tinea capitis
- ringworm of the body
- tinea corporis
- jock itch
- tinea cruris
- ringworm of the nails
- tinea unguim
- Pathogenecity- Dermatophytes invade keratinized structure and produce _____ to metabolize _____ as a nutrient
-
keratinase
keratin - The causes of dermatophytosis are a series of fungi called dermatophytes. Give 3 examples.
-
Trichophyton (ascomycete)
Microsporum (ascomycete)
Epidermophyton (deuteromycete) - What are three major symptoms of Dermatophytosis?
- itching, bad odor, rash
- Symptoms of Dermatophytosis include itching, bad odor, rash, accompanied by ______ which exude fluid when scratched leaving a scaly ring.
- blister-like lesions
- Symptoms of Dermatophytosis include itching, bad odor, and rash, accompanied by blister-like lesions which exude fluid when scratched leaving a scaly ring. Also, ____, change of _____, and inflammation may occur
-
hair loss
change of hair color - What are three forms of treatment for dermatophytosis
-
1) Use of powders
2) Change Local pH
3) Anti-fungal - use of powders
- powders dry infected area
- Change Local pH (2 pts)
-
1) Certain acids are active against fungi
2) undecyclenic acid is the main ingredient of Desenex - Desenex is an ointment, with its main ingredient being ______, that is active against fungi
- Undecyclenic acid
- Anti-Fungal (2 types)
-
1) Miconazole (micatin)- topical, for vagina
2) Griseofulvin- oral, causes hyphae to shrivel - Antifungals. What type of drug is an antifungal?
- Polyenes
- Polyenes combine with ____ in fungal plasma membrane
- sterols
- Polyenes combine with sterols in fungal plasma membrane. This makes the membrane excessively _____
- permeable
- Antifungals come from _____
- Streptomyces
- Antifungals are used to treat systemic fungal diseases such as _____ and _____
- coccidioidmycosis, histoplasmosis
- Why do antifungals have a limited use?
- toxicity to kidneys limits use
- Give two examples of Imidazoles (antifungal antibiotic)
- Clotrimazole, ketaconazole
- Are imidazoles natural, synthetic, or semi-synthetic?
- synthetic
- Imadazoles interferes with sterol synthesis in fungi, with possibly other _______ effects
- antimetabolic
- Imidazoles treats _______
- cutaneous mycoses
- Ketoconazole, taken orally, can be used for _______
- systemic mycoses
- Imidazoles has possible ____ damage
- liver
- What has a similar mechanism of action as imidazoles?
- triazoles such as fluconazole
- Griseofulvin blocks ________ assembly and interfere with ______, inhibits fungal reproduction
-
microtuble
mitosis - Griseofulvin comes from ____
- Penicillium
- Griseofulvin is used to treat ______ because it selectively binds keratin
- superficial mycoses