19-3 Diseases Caused by Bacteria and Viruses

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19-3 Diseases Caused by Bacteria and Viruses

• Pathogens disease-causing agents.
• Bacteria help in digestion, control growth of
  other bacteria.
• Pasteur showed that bacteria cause disease.
• Damaging cells of the infected organism for food.
• Release toxins that travel throughout the body
  interfering with the normal activity of the host.

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Bacteria

• Using Cells for food
• Mycobacterium tuberculosis causes tuberculosis,
  inhaled into the lungs, destroys the lung tissue.
• May enter blood vessel and travel to new sites in
  the body where it destroys more tissue.

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• Releasing Toxins
• Streptococcus causes strep throat.
• Release toxins into the bloodstream.
• Can cause scarlet fever.
• Diphtheria, caused by Corynebacterium
  diphtheriae, infects the tissues of the throat,
  releases toxins into the bloodstream.
• Breathing problems, heart failure, paralysis,
  death.

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Prevention

• Vaccine
• preparation of weakened or killed pathogens.
• When injected, prompts the body to produce
  immunity to the disease.
• Immunity is the bodys ability to destroy new
  pathogens.
• Antibiotics
• block the growth and reproduction of bacteria.
• Cure bacterial diseases.

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Controlling Bacteria

• Sterilization
• Heat
• Autoclave
• Disinfectants
• Chemical solutions
• Overuse increases the likelihood that common
  bacteria will evolve to become resistant to them
• Food processing
• Refrigeration
• Boiling, frying, steaming

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Viral Disease in Humans

• Attack and destroy certain cells in body.
• Causing symptoms
• Poliovirus kills cells of the nervous system,
  paralysis.
• Cannot be treated with antibiotics.
• Prevention
• Vaccines

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Viral Disease in Animals

• Foot-and-mouth disease
• Virus that infects cattle, sheep, and pigs
  (1990s)
• Thousands of cattle were killed.

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Viral Disease in Plants

• Tobacco mosaic virus
• Harder to infect cells, plant wall
• Viruses adaptive to break down wall.

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Viroids and Prions

• Viroids disease in plants
• Prions disease in animals
• Viroids single stranded RNA, no capsid. Disrupt
  the metabolism of the plant cell.
• Prions scrapie, disease in sheep. Protein that
  causes disease.
• Mad cow disease (Bovine Spongiform Encephalitis)
• Creutzfeldt Jakobs Disease
• http//www.youtube.com/watch?vbQk5UnWgqUE

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20-1 The Kingdom Protista

• Protist eukaryotes
• Plant-like photosynthesis
• Fungi-like decomposers, parasites
• Animal-like heterotrophs
• Evolution 1.5 billion years ago first appeared.

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20-2 Animal-like Protists Protozoans

• Zooflagellates swim using flagella
• Phylum Zoomastigina
• Absorb food through their cell membrane.
• Asexual reproduction
• Sexula reproduction

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Animal-like

• Sarcodines pseudopods.
• Feeding and movement
• Ex. Amoebas
• Amoeboid movement cytoplasm of cells streams
  into the pseudopod.
• Capture and digest particles by surrounding it.
• Food vacuole temporarily sore food
• http//www.youtube.com/watch?v7pR7TNzJ_pA

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Animal-like

• Ciliates cilia, phylum Ciliophora
• Cilia used for feeding and movement.
• Ex. Paramecium
• Trichocysts very small bottle-shaped structures
  used for defense.
• Release stiff projections that protect the cell.
• Two nuclei macronucleus (keeping multiple copies
  of genes), micronucleus (reserve copy of genes)
• http//www.youtube.com/watch?vl9ymaSzcsdY

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• Gullet mouth structure
• Anal pore waste material are removed.
• Contractile vacuoles collect water

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Conjugation

• Exchange of genetic material
• Two paramecia attach themselves to each other
• Exchange on micronucleus from each pair
• Not a form of reproduction, no new individuals
  are formed.
• Sexual process uses meiosis to produce new
  combinations of genetic information.

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Animal-like Protists

• Sporozoans do not move on their own
• Parasitic
• Need host cell

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Animal-like Protists and Disease

• Malaria
• African sleeping sickness.
• Malaria sporozoan Plasmodium, carried by femal
  Anopheles mosquito.
• Found in mosquito saliva, enters the humans
  bloodstream.
• Infects liver cells
• Red blood cells, multiplies rapidly
• RBC burst, parasite released in bloodstream
  producing chills and fever
• (many forms resistant to drugs)
  http//www.youtube.com/watch?vszlfndj0TFE

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Other Protistan Disease

• Trypanosoma causes African sleeping sickness.
• Bite of the tsetse fly
• Destroy blood cells and infect other tissues in
  the body.
• Fever, chills, and rashes. Infect nerve cells.
• Entamoeba amebic dysentery. Live in intestines,
  absorb food from host.

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Ecology of Animal-like Protists

• Organisms
• Sease and lakes
• Trichonympha GI tract of termites, help to
  digest wood.

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20-3 Plantlike Protists

• Euglenophytes two flagella, no cell wall
• Ponds and lakes
• Eyespot cluster of reddish pigment
• Pellicle instead of cell wall, intricate cell
  membrane

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Plant-like

• Chrysophytes yellow-green algae and golden-brown
  algae
• Gold-colored chloroplasts

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Plant-like

• Diatoms delicate cell walls rich in silicon,
  (glass).
• http//www.youtube.com/watch?v0z-zBy3UQQEfeature
  related

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Plant-like

• Dinoflagellates half photosynthetic, half
  heterotrophs
• Two flagella
• Cellulose protects cell
• Give off light when agitated
• Ocean
• http//www.youtube.com/watch?vT2xh9-UPSlU

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• http//www.youtube.com/watch?v9frgs8lUNacfeature
  fvwrel

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Ecology of Unicellular Algae

• Fresh and salt water
• Phytoplankton near surface of the ocean.
• Most of the photosynthesis
• Source of food

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Algal Blooms

• Waste is excessive populations of euglenophytes
  and other algae grow in abundance
• Deplete the water of nutrients
• Algae dies, decompose, taking oxygen out of
  water.
• Disruption of other life in the ecosystem.

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• Outline chapter 20

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20-4 Plantlike Protists

• Red algae great depths, efficient at harvesting
  light energy
• Phycobilins pigments, absorbs blue light.
• Can grow in many locations.
• 260m deep

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Brown Algae

• Phylum Phaeophyta
• Dusky plants
• Chlorophyll a and c
• Brown accessory pigment, fucoxanthin
• Largest, most complex
• Giant kelp (60m)

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Green Algae

• Phylum Chlorophyta, green plants
• Share many characteristics w/ plants, same
  photosynthetic pigments and cell wall
  composition.
• Cellulose in cell walls
• Chlorophyll a and b
• Store food as starch

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Unicellular Green Algae

• Chlamydomonas
• Ponds, ditches, wet soil
• Egg shaped cell, two flagella
• Lack large vacuoles, two small contractile
  vacuoles

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Colonial Green Algae

• Spirogyra, threadlike colonies called filaments
• Volvox, hollow spheres

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Multicellular Green Algae

• Sea lettuce
• Bright-green marine alga
• Found along rocky seacoasts

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Reproduction in Green Algae

• Both diploid and haploid generation.
• Alternation of generations sexual and asexual
  reproduction.

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Reproduction in Chlamydomonas

• Most of its life in the haploid stage
• Reproduces asexually if suitable conditions
• Zoospores cells produced by mitosis.
• Unfavorable conditions sexual reproduction,
  haploid cells go through mitosis, but instead of
  releasing zoospores, the cells release gametes.

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• Gametes are of two opposite mating types, and
  -.
• Gametes gather in large groups
• and gametes form pairs that soon move away
  from the group.
• Join flagella and spin around in the water.
• Fuse forming a diploid zygote.

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• Zygote goes to bottom and grows a thick wall.
• When conditions are favorable again it grows and
  divides by meiosis to produce 4 haploid cells.

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Reproduction in Ulva

• Gametophytes gamete-producing plants.
• Spores haploid reproductive cells.
• Sporophyte spore-producing organism

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Project

• Poster, in color
• Cartoon drawings
• Bacteria, Protists, and Fungi
• Short explanation of each type.
• Visually appealing, include main points of each
  Kingdom with drawings
• Test grade
• Due Next Friday