Eukaryotes
What are the basic differences again? Characteristic Prokaryotes Eukaryotes # of cells Unicellular Uni or multi DNA shape DNA is circular, no histones DNA in chromosomes w/histones DNA location Free in cell In PM-bound nucleus True organelles? No Yes Ribosomes 70S 80S First amino acid in protein Formylmethionine Methionine Cell wall? Yes-peptidoglycan No (animalia); Yes (plantae—cellulose); Fungi (chitin) Reproduction Binary fission three ways to reproduce Mitosis
Do they have flagella? Some do! Some also have cilia Both made of 9+2 pattern of microtubules
Do they have cell walls? Most do… Some have a glycocalyx Plantae (cellulose), fungi (chitin), protists (called the pellicle) Cell wall is chemically simpler Since no PPG, antibiotics do not harm eukaryotes Some have a glycocalyx Animalia
How about a PM? Yes—all have Fluid mosaic theory Very similar to prokaryotes Phospholipid bilayer w/ Proteins Cholesterol Fluid mosaic theory Semi-permeable membrane For small items Endocytosis and exocytosis For bigger items
What’s different about the cytoplasm? Contains Cytosol Organelles Cytoskeleton Cytoplasmic streaming
What about the organelles? True organelle membrane-bound Performs specific function Eukaryotes have organelles
What is the nucleus? DNA storage site Director of _______ synthesis Nuclear envelope Nuclear pores Nucleoli Chromatin
What about eukaryotic DNA? DNA wrapped around histones Chromatin vs chromosomes Mitosis and meiosis Neither in prokaryotes
What are some of the organelles? Endoplasmic reticulum Smooth Rough
What are some of the organelles? Ribosomes 80S (40S + 60S) What is it in prokaryotes? Chloroplasts and mitochondria have 80S ribosomes More on why this is later
What are some of the organelles? Golgi complex Transport vesicle Transfer vesicle—between cisterns Secretory vesicles Storage vesicles
What are some of the organelles? Lysosomes Single membrane Digestive enzymes
What are some of the organelles? Vacuoles Space or cavity Sometimes used for endocytosis Storage Water retention
What are some of the organelles? Mitochondria (mitochondrion) Inner membrane = cristae Filled with matrx Have some DNA and 70S ribosomes More about why later!
What are some of the organelles? Chloroplasts Stacked thylakoids 70S Ribosomes and DNA More on why later!
What is the cytoskeleton? Microfilaments microtubules
Why is there DNA in mitochondria and chloroplasts? Endosymbiotic theory
Types of Eukaryotes A survey by kingdoms
Why should I care about microbial eukaryotes? Over half the world is infected with them! Some examples: Malaria Hookworm Tapeworms African trypanosomiasis
What is the Kingdom Fungi? Macroscopic fungi Microscopic fungi
Mycology: The Study of Fungi
What are the characteristics of fungi? Chitin Hyphae pseudohyphae Heterotrophic saprobes
What are the characteristics of fungi? Yeasts vs. Hyphae Dimorphic
Yeasts Unicellular fungi Fission yeasts divide symmetrically Budding yeasts divide asymmetrically Figure 12.3
Dimorphism Pathogenic dimorphic fungi are yeastlike at 37°C and moldlike at 25°C Figure 12.4
How do fungi reproduce? Asexual spore Sporangiosphore Conidiospore Formation Sporangiosphore Conidiospore Arthrospore Blastoconidium Chlamydospore
How do fungi reproduce? Sexual spore formation Plasmogamy: Haploid donor cell nucleus (+) penetrates cytoplasm of recipient cell (–). Karyogamy: + and – nuclei fuse. Meiosis:Diploid nucleus produces haploid nuclei (sexual spores).
Sexual Spores Zygospore: Fusion of haploid cells produces one zygospore. Figure 12.6
Sexual Spores Ascospore: Formed in a sac (ascus). Figure 12.7
Sexual Spores Basidiospore: Formed externally on a pedestal (basidium). Figure 12.8
Fungal Diseases (Mycoses) Systemic mycoses: Deep within body Subcutaneous mycoses: Beneath the skin Cutaneous mycoses: Affect hair, skin, and nails Superficial mycoses: Localized, e.g., hair shafts Opportunistic mycoses: Caused by normal microbiota or environmental fungi
Zygomycota Conjugation fungi Coenocytic Produce sporangiospores and zygospores Rhizopus, Mucor (opportunistic, systemic mycoses)
Ascomycota Sac fungi Septate Produce ascospores and frequently conidiospores. Aspergillus (opportunistic, systemic mycosis) Blastomyces dermatitidis, Histoplasma capsulatum (systemic mycoses) Microsporum, Trichophyton (cutaneous mycoses)
Basidiomycota Club fungi Septate Produce basidiospores and sometimes conidiospores. Cryptococcus neoformans (systematic mycosis)
Economic Effects of Fungi Positive Effects Negative Effects Saccharomyces Bread, wine, beer Food spoilage Trichoderma Cellulose used for juices and fabric Cryphonectria parasitica (chestnut blight) Taxomyces Taxol production Ceratocystis ulm (Dutch elm disease) Entomorphaga Gypsy moth control
What is the kingdom Protista? Subkingdoms Algae Protozoa
What are the algae? Autotrophs Plankton Red tide: diatoms Photosynthetic Plankton Red tide: diatoms
What are the protozoa? Unicellular Heterotrophs Encystment Reproduce Asexually Conjugation
What are the protozoa? Classified on locomotion Phylum Motility Example Sarcodina Pseudopods video Amoeba Mastigophora Flagella rush hour Euglena Cilophora Cilia a relative Paramecium Apicomplexa Non-mobile Plasmodium (pic above)
Can you give some pathogenic examples?
What are helminths? Multicellular Heterotrophs Pathogenic groups include: Flatworms Tapeworms Trematodes Roundworms
Humans as Intermediate Host Figure 12.28
Remember!