| Question | Answer |
|---|---|
| study devoted to study of fungi | mycology |
| major decomposers of carbon compounds on earth found widespread in nature | fungi |
| How can fungi morphologically present | unicellular as small as a bacteria or multicellular complex organisms as muschrooms |
| Are fungi eukaryotes or prokaryotes | eukarytoes |
| Are fungi unicellular or multicellular | both |
| What is the cytoplasm surrounded by in fungi and how is this different then mammalian cells | cytoplasm is bound by a cytoplasmic membrane which has actin and contain ergosterol instead of cholesterol as mammalian cells |
| Why is the fact that fungi have ergesterol in place of cholesterol important to medicine | we can target ergesterol with medications to fight fungal infections |
| do fungi have organelles | yes all the same organelles as mammals |
| what is the fungal cell wall made of | made of polysacharrides such as mannan, glucans, and chitins |
| composed of long unbranched chains of poly-n-acetylglucosamine inert insoluble and rigid provides structural support for the fungi cell wall | Chitins |
| Glucosyl polymers may form fibril to increase the strength of the fungal cell wall | Glucans |
| form complex with protien and is present on the surface and structural cell matrix of the fungal cell wall determinants of serologic specificities | mannan |
| what are the strucutres in the fungal cell wall that are most responsible for causing immunological responses to most of the medically important fungi | Mannans and galactomannans |
| What is the metabolism of fungi | heterotrophic- which means then need exogenous carbon and nitrogen they don't have photosynthetic mechanisms |
| are there any anaerobic fungi | none there are aerobes and some faculative anaerobes |
| How do fungi metabolize larger or tougher structure to break down | they use an exoenzyme to solublizes the structures these enzymes often function as a virulence factor |
| what is clinically important of the exoenzymes fungi use for metabolism | it can function as a virulence factor |
| What are the three divisions of fungi based on the temperature at which they grow | psychrophile 0-20c mesophile 30-40c thermophilic 40-50c |
| what is the PH range for fungi | 2.2-8.5 clinically important grow at 6.5-7.0 |
| What is a critical environmental condition for most fungi for the to grow appropriatly | water availability most require 80-90% humidity |
| are most fungi photosensitive | yes |
| What are the different morphologies for fungi | yeast, mold(hypha or mycellium) or dimorphic can be both |
| What is dimorphism | ability of a fungus to grow as a mold or yeast (yeast like form) |
| At what temperature does dimorphic fungi grow as a mold and what temperature as a yeast | mold at ambient room temp yeast at 37c (body temp) |
| what are the 5 medically important dimorphic fungi | blastomyces dermatitidis coccidioides immitis histoplasma capsulatum paracoccidioidis brasiliensis sporothrix schenckii |
| What disease can bastomyces dermatitidis, histoplasma capsulatum and paracoccidioidis barsiliensis cause | pneumonia |
| What disease can coccidioides immitis cause | respiratory pathogen |
| what disease can sporothrix schenckii cause | rose gardeners disease sub q fungal infection |
| What two ways can fungi reproduce | asexual- via budding, or seperation of hyphal elements Sexual- two cells fuse to form diploid nucleus which goes through meiosis to form spores |
| part of the fungi below the surface is called | vegetative hypha- acquire nutrients for the fungus |
| part of the fungi above the surface is called | aerial hypha involved in reproduction via spores or conidia |
| what are the three types of spores formed in sexual reproduction of fungi | zygospores, ascospores and basidiospores |
| what is different between ascospores and basidiospores | ascospores are borne internally in a sac, basidiospores borne externally on a club sheath structure |
| what is unique about yeast forms of fungi | they can split like bacteria through fission or can undergo budding |
| What are the 4 phylum of fungi | zygomycota, ascomycota, basidiomycota, deuteromycota |
| sexual reproduction through zygospores asexual reproduction through sporangiospores | zygomycota |
| sexual reproduction through ascospores within sacs or asci asexual reproduction through blastoconidia or conidia on conidiophores | ascomycota |
| sexual reproduction through basidiospores on the surface of basidium asexual repro through conidiogenesis | basidiomycota |
| no sexual stage, asexual repro through conidiogenesis | deuteromycota |
| Classification of fungi that involves outer layer of skin, nail or hair rarely invade deeper tissues or viscera | superficial fungi |
| fungi confined to sub q tissues rarely spread systematically usually form deep ulcerated skin lesions or fungating masses | subcutaneous fungi |
| class of fungi that may involve deep viscera and become widely disseminated in the body | Systemic (deep) fungi |
| class of fungi that have low inherent virulence and are common in all environments and only take root when a chance presents itself | opportunistic mycoses |
| systemic mycosis that can infect the brain | aspergillus fumigatus |
| Systemic mycosis that can infect lungs especially in immunocompromised patients | pneumocystis carinii |
| What are some factors that can predispose an individual to fungal infections | steroid hormone therapy prolonged antibiotic treatment long term treatment stomach with h2 blockers diabetes mellitus high starch or sugar diets compromised immune system |
| what part of the immune system kills most fungi but what fungi can avoid it | innate immune response with neutrophils kills most fungi; dimorphic fungi are resistant to phagocytosis |
| part of the immune system that produces antibodies to opsonize the fungi promoting phagocytosis | humoral immune response of adaptive immune system |
| Part of immune system where T-cells protect the body from fungal infections | Cell mediated immune response of adaptive immune system |
| how can you diagnose fungal infections | KOH prep cultures serology DNA probe- limited effectiveness identify by characteristics mold or yeast |
| What are the three areas that drug treatments target for antifungal therapy | target plasma membrane synthesis and production, target cell division, targer nucleic acid synthesis |
| what drugs target plasma membrane synthesis/ function of fungi | polyenes, azoles and allyamines |
| drug that targets cell division of fungi | griseofulvin |
| drug that targets nucleic acid synthesis of fungi | flucytosine |
| how do allyamines stop plasma membrane synthesis/function | inhibit cyochrome enzyme p450 demethylase that converts lanosterol to ergosterol that is a major part of cell membrane |
| how does griseofulvin stop fungi cell division | only effective against fungi in keratininc skin layers it disrupts microtubules and stops cell divisions |
| how does flucytosine stop fungi nucleic acid synthesis | it inhibits thymidylate synthatase |
