Morphology of Bacteria, Fungi + Parasites

What is the structural and functional unit of all living organisms?

What is the structural and functional unit of all living organisms?

the cell

Cells w/o membranes + single chromosome - _________ ; cells with nuclear membrane + ER - ______________

prokaryotes, eukaryotes

Viruses have _______ evolution + 3 examples

regressive, genes protected by protein shell, little enzymes, depend on host

bacteria are examples of ________ and protozoa and fungi are examples of ___________

prokaryotic, eukaryotic

Shapes of cocci

equal diameters, kidney, lance-tip, oval

Spatial arrangement of cocci

diplo, clumps, tetrads, chain, eight and isolated

Shapes of bacilli

straight w/ cut/round ends, curved w/ pointy/swollen ends, deformed,

Spatial arrangement of bacilli

diplobacili, streptobacili, letters-like, irregular

Shapes of spiral-shaped bacteria

comma-like, w/ rigid/flexible coils

Size of cocci

0.5-2 mm

Size of bacilli

0,5-10 mm x 0,3-2 mm

Size of vibrio

1,5-3 mm x 0,5 mm

Size of spirochetes

6-20 mm x 0,15-0,5 mm

Bacterial wall - basal layer

peptidoglycan + N-Acetyl-muramic acid + -glucosamine (bound by polypeptides)

Bacterial cell wall for gram +

thick, rigid + simple, made of peptidoglycan (80%)+ teichoic acids and glycolipids (20%)

Bacterial cell wall for gram -

thin, flexible + complex, made of peptidoglycan (20%), periplasmic space + special structures: lipoproteins + ext. membrane (lipoproteins+polysaccharides) (80%)

Special structures of bacterial cell wall for gram -

• lipoproteins bind ext membrane by peptidoglycan

• LPS on ext. surface, has antigen (endotoxin)

Role of bacterial wall

• mech support

• protects

• participates in osmosis + diffusion + division

• base of somatic antigens + phage receptors

• provides staining characteristics

Cytoplasmic membrane of bacteria

surrounds cytoplasm, fluid mosaic model

Role of cytoplasmic membrane of bacteria

• controls osmotic pressure + diffusion

• has enzymes for respiratory metabolism

• involved in bacteria growth + division

Cytoplasm of bacteria

complex colloid - proteins, carbs, fats, h20, minerals, lots of RNA (basophilic)

Granulations of bacterial cytoplasm

• ribosomes

• volutin (ernst corpuscles, metachromatic grains)

• inclusions (glycogen, starch)

• vacuoles

Nucleoid of bacteria

• not delimited by membrane (not nucleus)

• single chromosome, double helicated + closed DNA

Facultative cell structures of bacteria - capsule

condensed extracell layer w/ slime layer (glycocalyx) which can't be seen by microscope

Capsule of bacteria - formed in

host, dependent on environmental factors

Composition of bacterial capsules according to species - polysaccharides __________, polypeptides ___________

• klebsiella, str. pneumoniae, neissaria

• bacillus anthracis

Role of bacterial capsule

• associated w/ virulence factor

• protects

• adhesin

• antigenic specificity

Facultative cell structures of bacteria - flagella

organs of locomotion, anchors in bacterial wall

Parts of flagella

thin + unbranched, has flagellin-myosin protein and antigen H, made of basal body + hook + filament

Arrangements of flagella

monotrichous, lophotrichous, amphitrichous, peritrichous

Pili

filamentous + rigid hair-like structures, in mostly gram +, in cytoplasmic membrane

Pili is composed of

pilin protein subunits, arranged helically - cylinder

Sex/conjugation pili

encoded by plasmids, attaches donor and recipient bacteria (horizontal gene transfer)

Adhesion pili

adheres bacteria to host cell w/ surface antigens, inhibits phagocytosis

Endospore

allows for resistance + species conservation

Spore

resistant + resting cell, destroyed at 120 degrees (moist heat)

Structure of spore

heat-resistant core (genome) + membranes

What spore membrane structure has peptidoglycan?

spore wall

What is the thickest spore membrane structure?

cortex (has unusual peptidoglycan)

The ______ is a spore membrane structure with keratin-like protein + impermeable

coat

Exosporium

lipoprotein membrane of spore

4 shapes of endospores

central spherical, central oval, subterminal (oval) and terminal (spherical)

What is mycose and what are they caused by?

fungal infection, caused by fungi from commensal flora or well adapted fungi for humans

3 classes of mycoses

superficial, systemic and opportunistic

Hyphae fungi + ex

filamentous fungi + tubular, mycelia + thallus

Single-cell fungi + ex

round + oval, yeast

Dimorphic fungi + ex

depends on enviro, yeast + mycelial

Mycotoxin

a toxin produced by a fungus

4 shapes of yeasts

§oval (Candida) §spherical (Torulopsis) §lemon (Kloeckera) §ellipsoid (Saccharomyces)

When yeasts bud they form

pseudomycellium

Chlamydospores

in low nutritional conditions, big + round cells and thick countours

cell wall of yeast

glycoprotein, ext layer is rough + bud scars + lots of chitin, int layer is irregular

cytoplasmic membrane of yeast

lipoprotein (role in permeability), fluid mosaic, location of enzyme synthesis for metabolism

How are molds (filamentous fungi) different from yeasts

• thicker walls w/ cellulose

• periplasmic space (bw wall + cytoplasm)

• 1-2 nuclei w/ 2-4 chromosomes each

Molds can be ________ (non-septate) or ______________ (septate)

unicellular (big), multicellular (common cell wall for multiple cells)

Hyphae

base element of molds/filamentous fungi, tubular + branched

Types of hyphae

• vegetative (tubes made after spore germination, apical growth)

• reproductive (made after a degree of dev. of vegetative, makes spores)

Mycelium

made of vegetative and reproductive hyphae

Imperfect mold spores - sporangiospores (molds)

for inferior molds + asexual reproduction, terminal hyphae (sporangiophore) ends w/ capsule (sporangium) filled with spores (sporangiospores) that burst out

Imperfect mold spores - condiospores (molds)

for superior and septate molds + sexual reproduction, appear after hyphae alteration and budding

Perfect spore (molds)

for sexual reproduction, formed by mating

Homothallism vs Heterothallism

perfect mold spore mating bw structures of same/diff cells

3 phylum of parasites

protozoa (unicellular), helminthes (worms) + anthropoda (insects)

Protozoa are found in

vegetative forms + dormant and inactive form (cyst)

Flagellate protozoa

eukaryotic, have flagella + cytostome (hole) to ingest nutrients

Amiboid protozoa

eukaryotic, irregular shape from pseudopods (extensions)

Sporozoa protozoa

shows degeneration in organs of locomotion + digestion, amplified spore reproduction

Ciliate protozoa

eukaryotic, around short cilia

Plathelminth helminthes

bilateral flatworms, hermaphrodites

Unsegmented (________) vs segmented (__________) plathelminthes

trematodes (small), cestodes (round head, neck + body w/ proglotids)

Nemathelminthes

cylindrical + elongated worms, unsegmented, males smaller than females

Eggs of flatworms

round, external coating, 6-hooked embryo

Eggs of roundworms

oval, not embryonated is Ascaris, early stage is ancylostoma, late stage is strongyloides

Ectoparasites

hematophagous insects