Chapter 12 Fungi Flashcards
What is Mycology?
The study of fungi
What is the kingdom, nutritional type, multicellularity, cellular arrangement of fungi?
Kingdom: Fungi
Nutritional Typs: Chemoheterotroph
Multicellularity: All, except yeasts
Cellular arrangement: unicellular, filamentous, and fleshy
What is the food acquisition method and reproductive characteristic features of Fungi?
Food acquisition method: absorptive
Reproduce characteristics: sexual and Asexual spores
What is the cell type of fungi and bacteria?
What is the cell membrane difference between these two?
What is the difference in cell wall?
Cell type: fungi - Eukaryotic Bacteria - Prokaryotic
Cell membrane fungi- sterols present Bacteria- Sterols absent, except in Mycoplasma
Cell wall Fungi- Glucans; Mannans; chitin (NO peptidoglycan). Bacteria - peptidoglycan
What are the difference in spores between Fungi and Bacteria?
Fungi: sexual and asexual reproductive spores
Bacteria: Endospores (not for repro) some asexual reproductive spores
What is the difference in metabolism between Fungi and Bacteria?
Fungi: Limited to Heterotrophic; aerobic, facultatively anaerobic
Bacteria: Heterotrophic, autotrophic, aerobic, facultatively anaerobic, and anaerobic
What were the characteristics of fungi in the hospital (nosocomial) setting?
They can be pathogenic in people with compromised immune systems
How are fungi beneficial?
Decompose dead plants (enzyme cellulase)
Plants dependent on symbiotic fungi, called mycorrhizae to absorb minerals and water
Also food (mushroom, bread, alcohol)
What is the energy source of Fungi?
What type of respiration are fungi involved in?
All are Chemoheterotrophic: they need organic
Aerobic or Facultative anaerobe
What is referred to a vegetative structure of fungi?
Refers to fungal colonies that grows and are involved in catabolism and growth
What is the Thallus and Hyphae of Fungi?
Thallus: body of fleshy fungi consist of long filaments
Hyphae: the long filaments which grow in immense proportions.
Vegetative growth have two kinds of hyphae, what are they?
Septate: most molds the hyphae contain cross-walls called septa, which divide then into distinct, uninuclecate cell-like units.
Coenocytic: no septum. They appear long, continuous cells with many nuclei
Hyphae that absorbs nutrients are called?
Vegetative hyphae
Hyphae for repro are called?
Reproductive or Aerial hyphae
Aerial Hyphae produces aerial spores
Hyphae that grows to a big mass is called? When is this seen
How can this be seen
Mycelium when conditions are right these are grown
Visible to the naked eye
The body of molds are called what and what do they consist of?
The fungal Thallus (body) consists of Hyphae
A mass if hyphae is called?
Mycelium
What are the characteristics of Yeasts?
Where are they found?
Unicellular, nonfilamentous that are typically spherically or oval.
Facultative anaerobic growth
Frequently found as white powdery coating on fruits and leaves.
Which yeasts divide symmetrically give an example?
Fission yeasts divid evenly to produce two new cells.
E.x. Schizosaccharomyces
Which yeasts divid unleavened and are called what?
Give an example of these yeast and what they are used for?
Budding yeasts
E.x. Saccharomyces
Use to make beer, wine, bread etc…
If buds fail to detach, it forms what and what is the name given to this outcome?
Given an example
If bids fail to detach, it forms short chain of cells called Pseudohyphae
Ex. Candida albicans
In the presence of O2 what will yeast produce?
What about in the absence of 02?
They use carbohydrates into CO2 and water
In the absence of O2, they ferment Alcohol and CO2
What is Fungal Dimorphism?
Pathogenic species exhibit dimorphism meaning two forms of growth, meaning they can either be a mold or a yeast.
What is the determinate for when a pathogenic fungi is either a mold or a yeast?
Yeast-like @ 37 degrees C
Mold-like @ 25 degrees C
What is the life cycle of Fungi
Two:
Asexual: by Fragmentation of hyphae or spores
Sexual: by spores (can be sexually or Asexually)
How are fungi identified or classified by?
What are these classification things used for?
Identified or classified by Spores
Spores are for repro, unlike bacterial endospores that are survival
How are Asexual spores formed?
Formed by Hyphae of one organism and germinate producing similar organism
How are sexual spores formed?
Formed by fusion of nuclei from two opposite mating types of the same species, which will result in the new organism that will have genetic characteristics of both.
Asexual Reproduction has two types of spores what are they?
Conidiospore
Sporangiospore
What are the characteristics of a Conidiospore or Conidium?
Give an example of this?
Not enclosed in a sac
They are produced in a chain at he end of a Conidiophore
E.x Aspergillus flavus and Penicillum
Conidia formed by the fragmentation of a septate hypha in to single, slightly thickened cells are called?
Give an example?
Arthroconidia
E.x, Coccidioides immitis
How are Bastoconidia formed?
Give an example?
Formed from the buds of its parent cells
Ex. Candida albicans and Cryptococcus
What is a thick-walled spore formed by rounding and enlargement within a hyphae segment?
What happens to the cells?
Give an example
Chlamydoconidia
The cell rounds and enlarges
E.x C.albicans
Where are Sporangiospores formed?
Where is this located?
Give an example?
Formed within a sac called the Sporangium
Located at the end of an aerial hyphae called the sporangiophore
Ex. Rhizopus
Sexual Reproduction of Fungi consists of three phases, what are they?
Plasmogamy
Karyogamy
Meiosis
What takes place during Plasmogamy?
Haploid nucleus of the donor cell (+) penetrates the cytoplasm of the receipting cell (-)
What takes place during Karyogamy?
+ and - nuclei fuse to form diploid zygote
What takes place during meiosis?
Diploid nucleus produces haploid nuclei (sexual spores)
Some of which are genetic recombinants
What is a Zygospore?
Fusion of haploid cells produces one zygospore
The zygosporangium contains the zygospore
When and where are Ascospores formed?
Give an example?
Forms with the nuclei of two cells that cal be either morphologically similar or dissimilar fuse
Formed in a sac like structure called an ascus
Ex. Talaromyces
What is Basidiomycota?
What doe they produce and where are they formed?
Club fungi that produce mushrooms
They are formed externally on a pedestal called (basidium)
What are the nutritional adaptation of fungi?
How do they eat?
Chemoheterotrophic- needs organic
They absorb their food not ingest it
How are fungi different from bacteria?
-pH
Respiration
Pressure
Moisture
Prefer pH 5
Molds are aerobic. Yeasts are facultative anaerobe
Fungi are more resistant to high osmotic pressure and can also grow on low moisture content
Why can Fungi grow in odd places like the bathroom walls, shoe leather, and newspapers?
They can breakdown complex molecules (metabolize them) better than bacteria
What are the medically important phyla of Fungi?
Zygomycota
Ascomycota
Anamorphs- used to Deutromycota
Basidiomycota
What is a fungal infection called?
How long do they last
Mycosis
Generally long lasting infections because fungi grow slow
Mycoses are classified into five groups according to the degree of tissue involvement and mode of entry. What are they?
Systemic, subcutaneous, cutaneous, superficial, or opportunistic
What is zygomycota and what are they also called?
They are also called conjugation fungi
Are saprophytic molds that have coenocytic hyphae
How do Zygomycota repro?
Sporangiospores ( asexual) which are in the sporangium and they need a suitable medium to fall on to germinate in to a new mold thallus
Zygospores (sexual) this is a large spore enclosed in a think wall
What is an example of Zygomycota?
Rhizopus stolonifer, which is black bread mold.
What are Ascomycota?
How do they reproduce?
What does conidia mean?
They are also called Sac fungi include molds with septate hyphae and some yeasts
They reproduce asexually via spores called conidiospores from conidia. The slightest disturbance causes the release of the spores like dust
They also repro sexually. Ascospres are sexual and produced in a sac called Ascus
What are teleomorphic fungi?
They produce both asexually and sexually
What are anamorphs?
Give an example?
They are Ascomycetes that have lost the ability to reproduce sexually (previously Deuteromycota)
Produce ASEXUAL spores only
Penicillium that arose from a mutation in a teleomorph
How are Anamorphs classified?
What are a few examples?
-rRNA sequencing to classify these organisms
Sporothrix (subcutaneous mycosis)
Stachybotrys, Coccidioides, Pneumocystis (systemic mycoses)
Candida albicans (cutaneous mycoses)
What are Basidiomycota?
What do they produce
Also called club fungi that also posses septate hyphae.
Produce Mushrooms
Where are the Basisiospores of Basidiomycota formed?
What else can they produce?
Basidiospores are formed on a base pedestal called a basidium. They are formed by meiosis
Some produce conidiospores
What are some examples of pathogenic Basidiomycota?
Cryptococcus neoformans (systemic mycosis)
- found in droppings of pigeons and transmitted in inhalation (airborne)
- causes meningitis with a high mortality rate
What are the Desirable Economical effects of Fungi?
Saccharomyces cerevisiae
Torulopsis
Trichoderma
Taxomyces
Saccharomyces cerevisiae - beer, wine, bread (rising agent), also used in genetic engineering to produce Hep B vaccine
Torolopsis: protein supplement
Trichoderma: produces cellulase
Taxomyces: produces Taxol (anti cancer drug)
Give an example of how fungi help the biological control of pests?
Entomophaga: kills gipsy moths
What are the undesirable economical effects of Fungi?
Spoil food: they grow on jam, jellies, fruits, grain and vegetables
What is Dutch Elm disease?
What is it cause by?
Creatocystis ulmi
It’s carried from tree to tree by a bark beetle. It blocks the trees circulation
What is Phytophthora infestans?
What happened because of this?
In 1800, 1 million people died in Ireland due to starvation because the potato crop failed
What are the 5 Fungal Diseases (Mycoses)?
Systemic Mycoses
Cutaneous mycoses
Subcutaneous mycoses
Superficial mycoses
Opportunistic mycoses
What is systemic mycoses?
How are the spores transmitted?
Fungal infections deep within the body.
Come from fungi that live in the soil
Spores are transmitted by inhalation that begins in the lungs then spreads
They are contagious from human to human
What is an example of Histoplasma capsulatum?
Causes Histoplasmosis
What is cutaneous mycoses (or Dermatomycosis) ?
What are three examples?
Affects the hair skin, and nails
Ex. Dermatophytes and they produce keratinase
Ex. Microsporum, Trichhophyton, Epidermophyton
What is subcutaneous mycoses?
What is an example and where is this found
beneath the skin from fungi that live in the soil and on vegetation
Spores enter through wound
Sporotrichosis by Sporothrix (gardeners hand)
What are Superficial mycoses?
Localized along hair shafts and in superficial epidermal cells and are prevalent in tropical climates
What are Opportunistic mycoses?
Generally harmless in its normal habitat but can become pathogenic in a host that is immunocompromized or who has been treated with broad spectrum antibiotics.
Caused by normal Microbiota or environmental fungi.
See in AIDS patients
What does Aspergillosis cause?
Aspergillus which is in people with lung diseases or cancer that have inhaled the spores
What does Candida albicans cause?
Candidiasis or yeast infections
Thrush: inflammation of the mouth and throat in AIDS patients
Opportunistic
What is Stachybotrys?
Grows on cellulose and water-damaged walls
Produces toxic spores that causes pulmonary hemorrhage
Opportunistic
What is Pneumocystis?
Causes pneumonia in AIDS patients
What is Lichens?
Is a combination of a green alga (or Cyanobacterium) and fungus
Mutualistic symboisis between an algae (or cyanobacterium) and fungus meaning both inhabitant areas that neither can live alone in!
Algae produces and secrets carbohydrates; fungus provides holdfast
Their survival is dependent on each other
What are the three types of Symbiotic Relationships of Lichens?
Mutualism
Commensalism
Parasitism
The lichen’s thallus or body forms when fungal hyphae grow around algal cells to become what?
The Medulla
What is formed with fungal hyphae project below the lichen body?
Rhizines or holdfasts
What is the protective covering over the agal layer and sometimes under it as well?
The cortex
What are the tree types of Lichens?
Fruticose- have finger like projections
Foliose- more leaf like
Crustose- grows flush or encrusted onto the substratum
What are some of the economical effects of Lichens?
Erythrolitmin- Used as dye in litmus paper that is used for pH
Usinc acid from Usnea is used as an antimicrobial in china. Has been used for 1000 years
Also used as dyes for clothing
What are Mycotoxins? What are some of the toxins that fungi produce?
What does Stacchybotrys produce?
Stacchybotrys produces Trichothecenes which stops protein synthesis
What does C.albicans and Trichophyton produce?
Secret protease
What does Claviceps purpurea cause?
The disease ergotism by producing toxin ergot (acts like LSD causing hallucination)
What does Aspergillus produce?
Produces aflatoxin which is a carcinogen
Peanut butter are sometimes recalled for this
What does Amanita phalloides produce?
Commonly known as death angel produces neurotoxin
What are the characteristics of Algae?
Mostly aquatic
Unicellular or multicellular
Photoautotroph (chlorophyll)
Lack the roots and stems of plants
What is the body of the multicellular called?
Thallus
Without roots and stems how to algae anchor them selves?
How to they eat and reproduce?
Holdfast: anchors the algae to rocks
Absorbs nutrients over the entire surface
Produce sexually or asexually
Where is agar extracted from?
From Red algae
What is the life cycle of Unicellular Algae?
REPRODUCTION
Asexual: cell divides by mitosis and produces new cells (cytokinesis)
Multicellular algae with thalli and filamentous forms can fragment and each piece can form new thallus or filament
Sexual: Gametes fuse (fertilization to form zygote)
What it Rhodophyta?
What are its characteristics?
Red algae
Have cellulose for cell walls
Most are multicellular
Store glucose polymer
Harvested for agar and carrageenan (food industry)
Where is Red algae found?
What is the significance of its color?
Found in deeper depths of the ocean
Live at greater depths than other algae
The red pigments enable red algae to absorb the blue light that penetrates the deepest into the ocean
What are the Chlorophyta?
What are its characteristics?
Green algae
They have cellulose for cell walls
Can be unicellular or multicellular
They also store glucose polymers
What are Diatoms?
They are unicellular or filamentous algae with complex cell walls that consist of pectin and a layer of silica. The two parts fit together like halves of a Petri dish.
Fossilized diatoms formed oil
Some are poisonous
What do poisonous diatoms produce?
What are the symptoms and how is it transmittted?
Produce domoic acid (neurotoxin)
Cause diarrhea and memory loss
Transmitted to humans by eating mussels that fed on poisonous diatoms
What are Dinofalgellates?
Called plankton for free-floating organism
Unicellular algae
Their rigid structure is due to cellulose in the PM
What does the Genus Alexandrium produce? Some Dinoflagellates produce this?
Produces neurotoxin called saxitoxins
This causes Paralytic Shellfish Poisoning (PSP)
They also produce 80% of the Earth’s Oxygen
Gives the ocean the red color
Define Protozoa
Unicellular
Kingdom: protist
Mostly Chemoheterotroph
Some are normal flora of animals
Under harsh conditions some Protozoa can form what?
Why does this happen?
Forms cysts.
This happens under certain adverse conditions and permits the organism to survive when food, moisture or oxygen are lacking, when temps are not suitable, or when toxic chemicals are present
How do Protozoa reproduce?
Asexually by fission, budding or schizogony.
And sexually
What is Schizogony?
Multiple fission; the nucleus undergoes multiple divisions before the cells divides and forms a new cell.
Protozoa also reproduce sexually by?
2 methods
Conjugation and gamete production
Some Protozoa produce gametes which are haploid sex cells, the two gametes fuse to form a diploid zygote
The Protozoa (ciliates) such as the paramecium do what type of sexual reproduction and how?
Conjugation
Each cells has a macronucleus and a micronucleus
The micronucleus migrate to other cells and fuses with the other cells micronucleus to produce daughter cells
What is the vegetative state of Protozoa?
Trophozoite- the feeding and growing stage
Feeds on bacteria and small particulate nutrients
How are Protozoa classified?
Sarcodina
Ciliophora
Mastigophora
Based on locomotion
Sarcodina: Pseudopod (Amoeba)
Ciliophora: Cilia (Paramacium)
Mastigophora: Flagella (Euglena)
How do Protozoa get nutrition?
Where does digestion take place?
Some absorb food through their PM
Some have a mouth called a cytosome done by ciliates
Some by phagocytosis (amoeba)
Digestion takes place in vacuoles in all Protozoa
What are the medically important phyla of Protozoa?
Archaezoa Microspora Amoebozoa Apicomplexa Ciliophora Euglenozoa
What are Archaezoa?
No mitochondria. Have Mitosome: which a remnant of mitochondria
They have multiple flagella
What is Trichomonas vaginalis?
What does it cause and how does this take place?
What are they lacking?
Infects the female vagina
No cyst stage
Transmitted by intercourse
Lacking mitochondria they have a mitosome which is a remnant of mitochondria
What is Giardia lambia?
Where is it found and what does it cause?
Archaezoa parasite
Found in the small intestine of humans and other mammals
It comes out in the feces as a cyst
Causes giardiasis
What are Microspora?
Like Archaezoa they have no mitochondria
They are obligate parasites
Reported since 1984 to be responsible for chronic diarrhea in AIDS patients
What are the characteristics of Amoebozoa or amoebas?
What is Entamoeba histolytica and what does it cause?
Move by pseudopods
Entamoeba histolytica is the only pathogen that causes Amoebic dysentery which is transmitted by cyst
It attaches to the galactose of the PM and causes the cell to lysis
What is Acanthamoeba cause and where is it found to infect?
Grows in water and infects the cornea and causes blindness
This can happen from unsanitary disinfecting of contact lenses
What is Apicomplexa?
Obligate Intracellular parasites
They have complex life styles that involves transmission between several hosts
The tips contain and enzyme to penetrate hosts tissue
What is an example of Apicomplexa?
Plasmodium: causes malaria that his transmitted by the mosquito Anopheles
The mosquito is referred to a definitive host why?
It harbors the sexually reproducing stage of the plasmodium
What is the infective stage called that the Anopheles harbors?
Called Sporozoite
Where does Asexual reproduction of the plasmodium take place?
Where does the sexual repro take place of the plasmodium?
Asexual Reproduction takes place within the human host liver making merozoites.
The sexual repro takes place when another mosquito bites the human and ingest the formed gametocytes and then the male and female gametocytes fuse to form a zygote that develops into sporozoites
What is another Apicomplexan that lives in the cells that line the small intestine?
What does it cause and how is it transmitted?
How are the sporozoites visible?
Cryptosporidium- causes diarrhea (gastroenteritis) by ingesting locust in contaminated water
Transmitted through feces of cows, cats, dogs
Sporozoites are visible inside the oocyst
Can be infected at a low dose
How do you prevent cryptosporidium?
Do not swim during and for 2 weeks after diarrheal illness
Avoid swallowing pool water
Wash hands after using the restrooms or changing diapers
What is the Apicomplexa Toxoplasma gondii?
Interacellular parasite of humans
The life cycle involves cats
The trophozoites called tachyzoites is the vegetative form that produces oocyst that contain sporozoite
The oocysts are excreted in cat feces
Also bad for pregnant women
What is Cyclospora cayentanensis?
Causes diarrhea associated with snow peas
What are the characteristics of Ciliates or Ciliophora?
Have and move by cilia that arranged in precise rows on the cells. Used for movement and to bring food to its mouth (cyostome)
They are complex cells
What ciliate is the only human parasite?
What does it cause?
Balantidium coli
Causes dysentery because the cyst is ingested by the host,
What are the characteristics of Eygleonzoa?
What are the two groups of them?
They move by flagella
Euglenoids
Hemoflagellates
What are the Euglenoids?
They are photoautotrophs
Have a red eyespot which is the pigment carotenoid that senses light
What are Hemoflagellates?
What is an example of one? What does it cause
Blood parasites that are transmitted by insects that bite the host. They have a long slender body and an undulating membrane
Trypanosoma gambiense- causes African sleeping sickness
Trypanosoma gambiense is carried by what?
T.brucei transmitted by the Tsetse fly
What does Trypanosoma cruzi cause?
Chagas’ disease
By the “kissing bug”
What are slime molds?
Closely related to the amoebae
Have characteristics in common with fungi and amoeba
What are the two taxa of Slime molds?
Cellular slime mold
Plasmodial slime mold
Which slime mold taxa are typical eukaryotic cells and what do they resemble.
Cellular slime mold
Resemble the amoeba and they live and grow by indgesting fungi and bacteria by phagocytosis
What happens when Cellular slime molds are faced wth unfavorable conditions?
Why does this occur, meaning what chemical messager is responsible for this occurring?
Large number of ameboid cells aggregate to form a single structure
Aggregation occurs because some produce cAMP that attract others to it this forms a slug
After a slug is formed from the aggregation of the ameboids due to cAMP what takes place?
Slug moves towards light, and forms a stalk. Some of the other ameboids go up the stalk to form a spore cap and germinate into spores
The spores are released and germinate to complete the cycle
What are Plasmodial Slime Molds
It’s a mass of protoplasm called a plasmodium with many nuclei (multinucleated).
When grown in the lab cytoplasmic streaming is observed. It moves to distribute nutrients evenly.
What is the life cycle of plasmodial slime molds?
Both sexual and asexual
