Protist, Fungi, Bacteria and Lichens. Are prokaryotes, do not have a nucleus Do not have complex...

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