浙江大学医学院：《医学真菌学 Medical Mycology》课程教学课件（PPT讲稿）Basic characteristics of fungi

Medical Mycology

1 Medical Mycology

Basic characteristics of fungi

2 Basic characteristics of fungi

Fungi are not plants or animals r Unlike animals, most fungi are nonmotile and possess a rigid cell wall r Unlike plants, fungi are nonphotosynthetic

3 Unlike animals, most fungi are nonmotile and possess a rigid cell wall Unlike plants, fungi are nonphotosynthetic Fungi are not plants or animals

Role of fungi in nature r There are approximately 80,000 recognized species of fungi r Most are beneficial to humankind o food o production of food o antibiotics and immunosuppressive drugs o used as model systems in molecular biology

4 Role of fungi in nature There are approximately 80,000 recognized species of fungi. Most are beneficial to humankind. food production of food antibiotics and immunosuppressive drugs used as model systems in molecular biology

Medical Mycology r the subject on pathogenic fungi o Some fungi act as the plant and animal pathogens in the agricultural industry o About 300 species of fungi cause human infections

5 Medical Mycology the subject on pathogenic fungi Some fungi act as the plant and animal pathogens in the agricultural industry. About 300 species of fungi cause human infections

Characteristics of fungi r Each fungal cell has at least one nucleus with a nuclear membrane, endoplasmic reticulum mitochondria and secretory apparatus r Most fungi are aerobes r Fungi secrete enzymes that degrade organic substrates into soluble nutrients which are then absorbed into the cell r Fungi have rigid cell walls composed of glucans and chitins r Maybe haploid or diploid r Both sexual and asexual reproduction

6 Each fungal cell has at least one nucleus with a nuclear membrane, endoplasmic reticulum, mitochondria and secretory apparatus Most fungi are aerobes Fungi secrete enzymes that degrade organic substrates into soluble nutrients which are then absorbed into the cell Fungi have rigid cell walls composed of glucans and chitins Maybe haploid or diploid Both sexual and asexual reproduction Characteristics of fungi

Comparison of fungi and bacteria Feature Fungi Bacteria diameter 3-15ψm( yeast) 0.5-2pm nucleus eukaryotic prokaryotic cytoplasm with mitochondria and without mitochondria and endoplasmic reticulum endoplasmic reticulum Cell wall chitin peptidoglycan spores sexual and asexual spore for survival, not for spore for proliferation proliferation dimorphism yes No metabolism Require organic May not require organic carbon and no carbon and maybe anaerobes anaerobes

7 Comparison of fungi and bacteria Feature Fungi Bacteria diameter 3-15 µ m(yeast) 0.5-2 µ m nucleus eukaryotic prokaryotic cytoplasm with mitochondria and endoplasmic reticulum without mitochondria and endoplasmic reticulum Cell wall chitin peptidoglycan spores sexual and asexual spore for proliferation spore for survival, not for proliferation dimorphism yes No metabolism Require organic carbon and no anaerobes May not require organic carbon and maybe anaerobes

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