1 eukaryotic cells the history of eukaryotes they first appeared approximately 2 billion years ago....
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Eukaryotic CellsEukaryotic CellsThe History of EukaryotesThe History of Eukaryotes
They first appeared approximately 2 billion years They first appeared approximately 2 billion years ago.ago.
Evidence suggests evolution from prokaryotic Evidence suggests evolution from prokaryotic organisms by organisms by symbiosissymbiosis..
Organelles originated from procaryotic cells Organelles originated from procaryotic cells trapped inside them.trapped inside them.
-> Endosymbiosis-> Endosymbiosis
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Endosymbiosis
Algae
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Eukaryotic CellsEukaryotic CellsEukaryotic Organisms in MicrobiologyEukaryotic Organisms in Microbiology
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Eukaryotic CellsEukaryotic CellsForm and Function of the Eukaryotic CellForm and Function of the Eukaryotic Cell
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Eukaryotic CellsEukaryotic CellsForm and Function of the Eukaryotic CellForm and Function of the Eukaryotic Cell
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Eukaryotic CellsEukaryotic CellsExternal StructuresExternal Structures
Locomotor Locomotor appendagesappendages
Flagella Flagella
-> long, sheathed -> long, sheathed cylinder containing cylinder containing microtubules in a 9+2 microtubules in a 9+2 arrangementarrangement
-> covered by an -> covered by an extension of the cell extension of the cell membrane membrane
-> 10X thicker than -> 10X thicker than prokaryotic flagellaprokaryotic flagella
-> function in motility-> function in motility
Cross section -> arrangement of proteins
Longitudinal section
Locomotor pattern
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Eukaryotic CellsEukaryotic CellsExternal StructuresExternal Structures
Locomotor Locomotor appendagesappendages
CiliaCilia
-> similar in overall -> similar in overall structure to flagella, structure to flagella, but shorter and more but shorter and more numerousnumerous
-> found only on a -> found only on a single group of single group of protozoa and certain protozoa and certain animal cellsanimal cells
-> function in motility, -> function in motility, feeding and filtering feeding and filtering
Structure
Locomotion
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Eukaryotic CellsEukaryotic CellsExternal StructuresExternal Structures
GlycocalyxGlycocalyx
- an outermost boundary that comes into direct contact withan outermost boundary that comes into direct contact with environmentenvironment- usually composed of - usually composed of polysaccharidespolysaccharides- appears as a network of fibers, a - appears as a network of fibers, a slime layer slime layer or a or a capsulecapsule- functions in adherence, protection, and signal reception- functions in adherence, protection, and signal reception- beneath the glycocalyx - beneath the glycocalyx
-> Fungi and most algae have a thick, rigid cell wall.-> Fungi and most algae have a thick, rigid cell wall.-> Protozoa, a few algae, and all animal cells lack a cell -> Protozoa, a few algae, and all animal cells lack a cell wall and wall and have only a membrane.have only a membrane.
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Eukaryotic CellsEukaryotic CellsExternal Boundary StructuresExternal Boundary Structures
Cell wall
- rigid, provides structural support and shape
-> Fungi have thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans.
-> algae – varies in chemical composition; substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate
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Eukaryotic CellsEukaryotic CellsExternal Boundary StructuresExternal Boundary Structures
Cytoplasmic (cell) membrane
- typical bilayer of phospholipids and proteins
- sterols confer stability
- serves as selectively permeable barrier in transport
- Eucaryotic cells also contain membrane-bound organelles that account for 60-80% of their volume.
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
- compact sphere, most prominent compact sphere, most prominent organelleorganelle of eukaryotic of eukaryotic
cellcell- nuclear envelope composed of nuclear envelope composed of two parallel membranes two parallel membranes
separated by a narrow space and is perforated with poresseparated by a narrow space and is perforated with pores
- contains - contains chromosomeschromosomes- nucleolus – dark area for rRNA synthesis and ribosomenucleolus – dark area for rRNA synthesis and ribosome
assemblyassembly
NucleusNucleus
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
NucleusNucleus
Cell division-> Mitosis
1. Replication of Chromosomes
2. Separation of replicated Chromosomes into 2
cells
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
Endoplasmic reticulum – two types:Endoplasmic reticulum – two types:
Rough endoplasmic reticulum (RER)–Rough endoplasmic reticulum (RER)– originates from the outer membrane of the nuclear envelop and extends in a continuous network through cytoplasm; rough due to ribosomes; proteins synthesized and shunted into the ER for packaging and transport; first step in secretory pathway
Smooth endoplasmic reticulum (SER)–Smooth endoplasmic reticulum (SER)– closed tubular network without ribosomes; functions in nutrient processing, synthesis and storage of lipids, etc.
Rough Endoplasmic reticulumRough Endoplasmic reticulum
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
Golgi apparatusGolgi apparatus
- consists of a stack of flattened sacs consists of a stack of flattened sacs called cisternaecalled cisternae
- closely associated with ERclosely associated with ER
- Transitional vesicles from the ER Transitional vesicles from the ER containing proteins go to thecontaining proteins go to the
Golgi apparatus for Golgi apparatus for modificationmodification and maturation.and maturation.
- Condensing vesicles transport Condensing vesicles transport proteins to organelles or proteins to organelles or secretory secretory proteinsproteins to the outside. to the outside.
-> The secretary pathway
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
LysosomesLysosomes
-> > vesicles containing enzymes vesicles containing enzymes that originate from Golgi apparatus that originate from Golgi apparatus used for breaking down material used for breaking down material
-> Trash bin of the cell !!!-> Trash bin of the cell !!!
-> involved in intracellular > involved in intracellular digestion digestion of food particlesof food particles and in and in protection protection against invading microbes against invading microbes (Phagocytosis) (Phagocytosis) andand absorbing any material (molecules) from outside (Endocytosis)
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
MitochondriaMitochondria
- consists of an outer membrane and an inner membrane with folds consists of an outer membrane and an inner membrane with folds calledcalled
cristaecristae
- Cristae hold the enzymes and electron carriers of - Cristae hold the enzymes and electron carriers of aerobic aerobic respirationrespiration..
- divide independently of cell- divide independently of cell
- contain DNA and procaryotic ribosomes- contain DNA and procaryotic ribosomes
- function in - function in energy productionenergy production
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
ChloroplastChloroplast
- found in found in algaealgae and and plant cellsplant cells
- outer membrane covers inner outer membrane covers inner membrane folded into sacs, membrane folded into sacs, thylakoids, stacked into granathylakoids, stacked into grana
- larger than mitochondrialarger than mitochondria
- contain photosynthetic contain photosynthetic pigmentspigments
- convert the convert the energy of sunlight energy of sunlight into chemical energyinto chemical energy through through photosynthesisphotosynthesis
- primary producers of organic - primary producers of organic nutrients for other organismsnutrients for other organisms
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
RibosomesRibosomes
- composed of rRNA and proteinscomposed of rRNA and proteins
- 40S and 60S subunits form 80S ribosomes40S and 60S subunits form 80S ribosomes
- larger than procaryotic ribosomes (70S)larger than procaryotic ribosomes (70S)
- function in - function in protein synthesisprotein synthesis
30S 50S 70S
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Eukaryotic CellsEukaryotic CellsInternal StructuresInternal Structures
CytoskeletonCytoskeleton
- flexible framework of proteins -> microfilaments and flexible framework of proteins -> microfilaments and microtubulesmicrotubules
- form form network throughout cytoplasmnetwork throughout cytoplasm
- involved in involved in movement of cytoplasmmovement of cytoplasm, amoeboid movement , amoeboid movement (motility), (motility),
transporttransport, and structural support, and structural support
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Eukaryotic CellsEukaryotic Cells
Eukaryotic MicrobesEukaryotic Microbes
-> Fungi-> Fungi
-> Algae-> Algae
-> Protozoa-> Protozoa
-> Parasitic worms-> Parasitic worms
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Eukaryotic CellsEukaryotic Cells
Kingdom FungiKingdom Fungi
100,000 species divided into 2 groups:100,000 species divided into 2 groups:
-> macroscopic fungi (mushrooms, puffballs, gill fungi)-> macroscopic fungi (mushrooms, puffballs, gill fungi)
-> microscopic fungi (molds, yeasts)-> microscopic fungi (molds, yeasts)
Majority are Majority are unicellularunicellular or or colonialcolonial; a few have cellular ; a few have cellular specializationspecialization
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Microscopic fungiMicroscopic fungi
Slime moldSlime mold
YeastYeast
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Macroscopic fungiMacroscopic fungi
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Eukaryotic CellsEukaryotic Cells
Microscopic fungiMicroscopic fungi
Exist in two morphologies:Exist in two morphologies:
-> -> yeast yeast – round ovoid shape, asexual reproduction, – round ovoid shape, asexual reproduction, unicellularunicellular
-> -> hyphaehyphae – long – long filamentousfilamentous fungi or molds fungi or molds
Some exist in either form – Some exist in either form – dimorphicdimorphic: :
mold-like at low temperature, yeast like at 37 degrees C,mold-like at low temperature, yeast like at 37 degrees C, characteristic of some pathogenic moldscharacteristic of some pathogenic molds
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Eukaryotic CellsEukaryotic CellsMacroscopic and Microscopic view – Macroscopic and Microscopic view –
Molds/fungiMolds/fungi
Mixed cultures of mold
Hyphal structures
Structural types of hyphae
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Eukaryotic CellsEukaryotic Cells
Macroscopic and Macroscopic and Microscopic view - YeastMicroscopic view - Yeast
Morphology of yeast
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Eukaryotic CellsEukaryotic Cells
Fungal NutritionFungal Nutrition
-> All are heterotrophic (org. Carbon Source)-> All are heterotrophic (org. Carbon Source)
-> Majority are harmless saprobes living off-> Majority are harmless saprobes living off dead plants and animalsdead plants and animals
-> Some are parasites, living on the tissues -> Some are parasites, living on the tissues ofof other organisms, other organisms, mycosesmycoses – fungal – fungal infectionsinfections
-> Growth temperature 20-> Growth temperature 20oo-40-40ooCC
-> Extremely widespread distribution in -> Extremely widespread distribution in manymany habitatshabitats
Mycellium growing on raspberries
Fungus growing on skin
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Eukaryotic CellsEukaryotic Cells
Fungal OrganizationFungal Organization
-> Most grow in loose associations or -> Most grow in loose associations or coloniescolonies
-> -> YeastYeast – soft, uniform texture and appearance – soft, uniform texture and appearance
-> -> Filamentous fungi Filamentous fungi – mass of hyphae called – mass of hyphae called myceliummycelium;; cottony, cottony,
hairy, or velvety texturehairy, or velvety texture
- hyphae may be divided by cross walls – - hyphae may be divided by cross walls – septateseptate
- - vegetative hyphaevegetative hyphae – digest and absorb nutrients – digest and absorb nutrients
- - reproductive hyphaereproductive hyphae – produce – produce sporesspores for reproduction for reproduction
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Eukaryotic CellsEukaryotic Cells
Fungal OrganizationFungal Organization
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Eukaryotic CellsEukaryotic Cells
Fungal Reproduction - AsexualFungal Reproduction - Asexual
-> All Fungi have asexual reproduction !!!-> All Fungi have asexual reproduction !!!
-> Primarily through spores formed on -> Primarily through spores formed on reproductive hyphaereproductive hyphae
-> -> AsexualAsexual reproduction – reproduction – sporesspores are formed through are formed through buddingbudding or or mitosismitosis; ; conidia or sporangiosporesconidia or sporangiospores
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Eukaryotic CellsEukaryotic Cells
Fungal Reproduction - SexualFungal Reproduction - Sexual
-> -> SexualSexual reproduction – reproduction – sporesspores are formed following are formed following fusion of fusion of malemale
and female strainsand female strains and formation of sexual structure and formation of sexual structure
-> Sexual spores and -> Sexual spores and spore-forming structuresspore-forming structures are one are one basis for basis for
classification.classification.
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Eukaryotic CellsEukaryotic Cells
Fungal Reproduction – sexualFungal Reproduction – sexual
-> -> ZygosporesZygospores– – diploiddiploid spores (2n)spores (2n) are formed following are formed following fusion of fusion of malemale
and female strains and female strains
zygospore germinateszygospore germinates -> -> meiosismeiosis occurs -> occurs -> haploid vegetative haploid vegetative cells cells areare
released.released.
-> -> AscosporesAscospores – – haploid spores (n)haploid spores (n), formed following , formed following fusion of malefusion of male
and female strainsand female strains in fungal sac -> in fungal sac -> ascusascus
zygote (fused) zygote (fused) cells undergocells undergo meiosis meiosis -> formation of-> formation of haploid haploid sporesspores
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Eukaryotic CellsEukaryotic Cells
Fungal Reproduction – sexualFungal Reproduction – sexual
-> -> AscosporesAscospores in a fruit in a fruit bodybody
Ascomycetes-> Penicillium
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Eukaryotic CellsEukaryotic Cells
Fungal Reproduction – sexualFungal Reproduction – sexual-> -> BasidiosporesBasidiospores – haploid sexual spores in a fruit – haploid sexual spores in a fruit bodybody
Basidiomycetes
Fruit body
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Eukaryotic CellsEukaryotic Cells
Fungal ClassificationFungal Classification
Subkingdom Amastigomycota – terrestrialSubkingdom Amastigomycota – terrestrial
-> inhabitants including those of medical importance:-> inhabitants including those of medical importance:
Fungi perfectiFungi perfecti (sexual + asexual spores): (sexual + asexual spores):
-> Zygomycota – zygospores; sporangiospores and some -> Zygomycota – zygospores; sporangiospores and some conidiaconidia
-> Ascomycota – ascospores; conidia-> Ascomycota – ascospores; conidia
-> Basidiomycota – basidiospores; conidia-> Basidiomycota – basidiospores; conidia
Fungi imperfectiFungi imperfecti (just asexual cycle know until now): (just asexual cycle know until now):
-> Deuteromycota – majority are yeasts and molds; no -> Deuteromycota – majority are yeasts and molds; no sexual spores known; conidiasexual spores known; conidia
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Eukaryotic CellsEukaryotic Cells
Roles of FungiRoles of Fungi
-> Adverse impact-> Adverse impact
- mycoses, allergies, toxin production- mycoses, allergies, toxin production- destruction of crops and food storagesdestruction of crops and food storages
-> Beneficial impact-> Beneficial impact
- decomposers of dead plants and animals- decomposers of dead plants and animals- sources of antibiotics, alcohol, organic acids, vitamins- sources of antibiotics, alcohol, organic acids, vitamins- used in making foods and in genetic studies- used in making foods and in genetic studies
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Eukaryotic CellsEukaryotic Cells
Roles of FungiRoles of Fungi
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Eukaryotic CellsEukaryotic Cells
Kingdom ProtistaKingdom Protista
-> -> AlgaeAlgae
Diatoms -> silica cell wall
-> -> ProtozoaProtozoa
Ameba
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Eukaryotic CellsEukaryotic Cells
Kingdom ProtistaKingdom ProtistaAlgaeAlgae
-> -> PhotosyntheticPhotosynthetic organisms organisms
-> Contain chloroplasts with chlorophyll and other pigments-> Contain chloroplasts with chlorophyll and other pigments
-> Produce large proportion of atmospheric O-> Produce large proportion of atmospheric O22
-> Most are free-living in fresh and marine water – -> Most are free-living in fresh and marine water – planktonplankton..-> Provide basis of food web in most aquatic habitats-> Provide basis of food web in most aquatic habitats
-> Classified according to types of pigments and cell wall-> Classified according to types of pigments and cell wall
-> Kelps, seaweeds, euglenids, green algae, diatoms, dinoflagellates,-> Kelps, seaweeds, euglenids, green algae, diatoms, dinoflagellates,
brown algae, and red seaweedsbrown algae, and red seaweeds-> Dinoflagellates can cause red tides and give off toxins that cause-> Dinoflagellates can cause red tides and give off toxins that cause food poisoning with neurological symptoms.food poisoning with neurological symptoms.
-> Used for cosmetics, food, and medical products-> Used for cosmetics, food, and medical products
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Eukaryotic CellsEukaryotic Cells
Kingdom ProtistaKingdom ProtistaProtozoaProtozoa
-> 65,000 species-> 65,000 species
-> Vary in shape, lack a cell wall -> Vary in shape, lack a cell wall
-> Most are unicellular; colonies are rare-> Most are unicellular; colonies are rare
-> Feed by engulfing other microbes and organic matter-> Feed by engulfing other microbes and organic matter
-> Most have locomotor structures – flagella, cilia.-> Most have locomotor structures – flagella, cilia.
-> Many can enter into a resting stage when conditions are-> Many can enter into a resting stage when conditions are
unfavorable for growth and feeding – unfavorable for growth and feeding – cystcyst..
-> Most are harmless, some are -> Most are harmless, some are animal parasitesanimal parasites
Pathogen Protozoa -> Malaria (Pathogen Protozoa -> Malaria (PlasmodiumPlasmodium falciparum/vivax/ovale/malariae), ),
Toxoplasmosis (Toxoplasmosis (Toxoplasma gondiiToxoplasma gondii))
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Eukaryotic CellsEukaryotic Cells
Kingdom ProtistaKingdom ProtistaCycle of Infection - ProtozoaCycle of Infection - Protozoa
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Eukaryotic CellsEukaryotic CellsParasitic Helminths (Worms)Parasitic Helminths (Worms)
-> 50 species parasitize humans.-> 50 species parasitize humans.
-> Acquired though ingestion of larvae or eggs in food; from soil or-> Acquired though ingestion of larvae or eggs in food; from soil or
water; some are carried by insect vectorswater; some are carried by insect vectors
-> Multicellular animals, organs for reproduction, digestion, -> Multicellular animals, organs for reproduction, digestion,
movement, protectionmovement, protection
Major Groups: 1. Flatworms Major Groups: 1. Flatworms
2. Roundworms2. Roundworms
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Eukaryotic CellsEukaryotic CellsParasitic Helminths (Worms)Parasitic Helminths (Worms)
Life cycle of roundworms
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