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Protist, Fungi,
Bacteria and Lichens
• Are prokaryotes, do not have a nucleus
• Do not have complex chromosomes
• Do not reproduce sexually
• Unicellular
• Lack cell organelles except ribosomes
• Can be autotrophs or heterotrophs
Cells have diversity of shapes, the most common being:
1. Spherical: coccus 2. Rod: bacillus3. Spiral: spirillium Grouping of cells includes:1. Staphylo: clustered2. Strepto: chain Diameter of cells 1-10 micrometers,
eukaryotes 10-100 micrometers
bacillus
Coccus
Spirillium
Strepto
Staphlo
Prokaryotes external cell walls maintain the cell shape, protect the cell and are composed of peptidoglycan (a modified sugar cross-linked by short (polypeptides.)
The peptidoglycan cell wall composition can be used to identify cells thru a staining process called gram stain
A stain used to distinguish 2 groups of bacteria by virtue of a structural difference in their cell wall:
1. Gram positive: • Have large amounts of peptidoglycan in cell
wall and stain blue2. Gram negative:• Have small amounts of peptidoglycan, stain
pink, and are more often disease-causing than gram positive.
• Gram negative bacteria
• Gram positive bacteria
Motile bacteria use one of 3 mechanisms to move:
1. Gliding along secreted slime
2. Axial filaments of spirochetes allow rotation and motion like a corkscrew
3. Flagella
Bacteria’s “Tail” (Flagella)
www.soulcare.org Sid Galloway
Bacteria’s “Tail” (Flagella)
Only an awesome intelligence could create such irreducible complexity.
Neither mitosis nor meiosis occurs DNA synthesis is almost continuous Cells divide by:1. Binary fission ( divide and produce 2
identical cells)2. Conjugation: exchange of genetic
material3. Spore formation: when growth
conditions become unfavorable, many bacteria form spores
1. Photoautotrophs: use light to synthesize orgnaic compounds. Ex cyanobacteria
2. Photoheterotrophs: need organic corabon but use light to make ATP
3. Chemoautotrophs: need only carbon dioxide to make their food
4. Chemohetrotrophs: need organic molecules for energy and as a source of carbon. Most bacteria fit here.
Chemohetrotrophs can be broken down into 2 subgroups:
1. Saprophytes decomposers that absorb nutrients from dead organic matter.
2. Parasites: bacteria that absorb nutrients from body fluids of living hosts.
1. Obligate aerobe: bacteria that need oxygen for cellular respiration
2. Facultative anaerobe: use oxygen when present, but in its absence , it can grow using fermentation. Ex giardia
3. Obligate anaerobe” those that are poisoned by oxygen. Ex Clostridium botulinium ( food poisoning)
1. Archaebacteria: live in extremely harsh conditions, divided into 3 main groups:
a) Methanogens: strict anaerobes, found in marshes and swamps
b) Extreme halophiles: live in water with extreme salinity (15 to 20 %), and form pink colored colonies on agar
c) Thermoacidophiles: live in habitats of 60-80C and pH 2-4
2. Eubacteria: true bacteria, capable of causing disease (pathogenic)
3. Cyanobacteria: blue-green algae, are larger than most prokaryotes, are photosynthetic
4. Prochorobacteria: new group of bacteria, only 2 species known
Nostoc
Oscillatoria
. . Any close Any close relationshiprelationship between between
species is called species is called symbiosissymbiosis..
1.Mutualism
2.Commensalism
3.Parasitism
Mutualism – A symbiotic relationship in which both
species benefit.
ParasitismParasitism – A – A symbioticsymbiotic relationshiprelationship in which in which oneone organism organism benefitsbenefits but the but the
other is other is harmedharmed..
Commensalism – A symbiotic relationship in which one
organism benefits and the other is not affected.
1/2 human diseases are caused by bacteria
Some pathogens are opportunistic…normally in the body but become pathogenic only when defenses are weakened. Ex Streptococcus pnemonia
Koch’s Postulate ( Robert Koch)• 4 criteria to substain a specific
pathogen as a cause of disease:
1. Find pathogen in all diseased individuals
2. Isolate diseased pathogen and grow in culture
3. Use culture to introduce disease in a test subject
4. Isolate same pathogen in test subject
Kingdom: Protista
• Almost all have flagella or cilia at some time in life cycle
• All can reproduce asexually, some can reproduce sexually
• Can be group as animal-like protist or algae-like protist
• Are unicellular eukaryotic organisms
• May be heterotrophic or autotrophic
• Are found almost anywhere there is water
• Can be either free-living or symbiotic
• Almost all are aerobic, using mitochondria for cell respiration
1. Rhizopoda: also called sarcodina• Includes amoebas and their relatives2. Actinopoda: includes radiolarians3. Foraminifera: marine organisms4. Apicomplexa: sporozoa5. Zoomastigina: flagellata6. Cilophora: paramecium
• Rhizopoda: also called sarcodina• Includes amoebas and their relatives• Simplest of protist• All are unicellular• Motility via pseudopodia• Inhabit fresh water, soil and marine• Most are free-living, but some are
parasitic ex amoebic dysentary
Amoeba• Kingdom: Protista Phylum Sarcodina
Amoeba
• Moving amoeba
• Includes radiolarians,
• primarily marine and have delicate shells, composed of silica
Radiolarian• Kingdom: Protista Phylum Actinopoda
• Exclusively marine
• Have porous, multichambered, calcium carbonate shells
• Nonmotile
• Reproduce by means of spores
• Ex plasmodium which causes malaria
Malaria Cycle – Plasmodium carried by Anopheles mosquitoes
• Heterotrophs that absorb organic molecules or phagocytizes prey
• Can reproduce asexually
• Ex trypanosoma which causes african sleeping sickness thru the bite of the tse tse fly
Trypanosoma• Kingdom: Protista Phylum Flagellata
PHYLUM ZOOMASTIGINA
• Ex paramecium
• Largest group
• Have 2 types of nuclei:
1. Macronucleus: large, around 50 copies of genome
2. Micronucleus: function in conjugation
Paramecium
•
Paramecium
Algae-like protist
Are aquatic organisms having chlorophyll a and accessory
pigments such as carotenoids
Spirogyra• Kingdom: Protista
1. Dinoflagellata: such as Pyrrophyta
• Pyrrophyta means Fire Protist
• cause red tides
2. Chrysophyta• Green Golden Protist
Example: Hydrodictyon
•
• 3 kinds: • 1. diatoms• 2. yellow gre3n
algae• 3. brown algae
3.Phaeophyta• Brown Protist
• Largest most complex protist
4. Rhodophyta
5. Euglenophyta: ex euglena
• Kingdom: Protista Phylum Euglenophyta
Euglena
Green protistExamples include volvox and
Chlamydomonas
Volvox• Kingdom: Protista Phylum: Chlorophyta
Chlamydomonas
• Kingdom: Protista
• Phylum: Chlorophyta
Protist that resemle fungi
1. Myxomycota: ex plasmodial slime mold
2. Acrosiomycota: cellular slime molds
3. Oomycota: watermold, white rust, mildew
Eukaryotes, multicellular ( except yeast which is unicellular), heterotrophs via
saprophytic activity
• Fungi are hetrotrophs that acquire nutrients by absorption in 3 main ways:
1. Saprophytes: absorb nutrients from dead organic material
2. Parasitic fungi: absorb nutrients form body fluids of living host. Some are pathogenic
3. Mutualistic fungi: absorbs nutrients from a host but reciprocate to benefit host
• Hyphae: filaments forming fungal body.
• The network of hyphae is known collectively as a mycelium
• Cell wall composed of chitin
• Fungi are nonmotile and have no flagellated stages in their life cycle.
• Spores are produced asexually when conditions are habitable, and sexually when stressed
• Sexual reproduction often involves conjugation in which hyphae of opposite mating stains join.
1. Zygomycetes: most primitive fungi and reproduce sexually, most are terrestrial fungi in soil and decaying organic material. Ex bread mold
Most primitive fungus to reproduce sexually
Zygomycetes
2. Ascomycetes: includes unicellular yeast and complex multicellular cup fungi
• Includes decomposers and mutualistic and parasitic symbionts
• Many live symbiotically with algae as lichen
Ascomycete
3. Basidiomycetes: ex mushroom
• Characterized by sexual reproduction
Basidiomycete
www.soulcare.org Sid Galloway
DON’T ever eat the ones in your yard!Never eat hallucinogenic mushrooms,
Like “Psilocybin”.
Reality is bad enough in this fallen world. Why make it worse.
4. Deuteromycetes: Fungi imperfect Reproduce asexually ( no
observable sex life) Ex penicillium
Deuteromycetes• Penicillium sp.,
LichensWhy did the algae and the fungus get together…..they took a lichen
to each other
• Lichens grow everywhere except where pollution occurs.
• Are good indicators of air pollution especially sulfur dioxide
• 2 theories as to the role of fungi:1. They benefit algae2. Controlled parasitism: fungi kills some algae
but not as fast as algae replenishes itself•
Crustose Lichen: crustlike
Foliose Lichen: leaf like
Fruiticose Lichen: shrub like
Mycorrhizae
• Are specific, mutualistic associations of plant roots and fungi
• Are seen in 90% of trees and majority of small vascular plants
• Necessary for optimal plant growth
Pathogenic Fungi
• RINGWORMs •
• athletes foot
Virus
• Depending on one's view point, viruses maybe regarded as aggregates of complexnonliving chemical, or very simple livingmicrobes.
• Viruses are not placed in any kingdom.• They are not composed of cells and are
incapable of growth without a host cell.• Viruses vary in size and shape ( smallest virus
is about .002 um — polio virus and largest is,3um — smallpox virus)
• There are no technical names for viruses.
• Viruses are classified based on types ofnucleic acid, morphological class, size ofcapsid, and number of capsomeres.
• Other considerations include: virus'ssusceptibility to microbial control agents, and immunological properties
• The virus particle is known as a virion.
• The nucleic acid portion of the virus is known as the genome, which is surrounded by a protein coat known as a capsid, which is formed from a number of individual protein molecules called capsomeres,'
• The combination of the genome and capsid is called the viral nucleocansid.
• Some kinds of viruses contain envelopes (enclosed nucleocapsids)( ex herpes,chickenpox, infectious mononucleosis) and some have projections from the envelopeknown as spikes, which help the virus attach to the hose cell, ExAIDs
• Antibiotics cannot be used to inactivateviruses because viruses do not perform the biochemical functions that antibiotics interfere with.
• However some drugs can interfere with viral replication (virus inducesthe living host cell to synthesize the essential components for the synthesis of new viral particles).
•
• Diagram of Virus
Rabies
AIDS Virus
Influenza Virus
Ebola Virus