Classification of Virus, Bacteria, Protists, and Fungi S3 BiologyWhat a virus is and isnt. A virus is not a cell. No nucleus, cell membrane, ribosomes, mitochondria, chloroplasts, etc.

A virus is very small. 3000 poloviruses could be contained in the period at the end of this sentence.

A virus is not complex. Genes: Humans (100,000), Bacteria (1000), a Virus just 5!

Viral Structure Nucleic Acid DNA or RNA, but not both.

Protein Coat (capsid) Protects the nucleic acid from its environment.

Envelope Only found in viruses that infect animals. Spike-like projections that recognize animal cells and bind to the cell surface

Viral Replication Viruses dont reproduce, they replicate. Viruses cannot replicate on their own. Host cells. Lytic Cycle. When the virus enters the cell it immediately begins to replicate, rapidly killing the cell. Lysogenic Cycle.Viral DNA is inserted into the host cells DNA. This DNA, called a PROPHAGE, may be reproduced several times and eventually reactivates

Are viruses alive? Properties of Life: Highly organized. Yes or no? Use energy. Yes or no? Grow and develop. Yes or no? Reproduce. Yes or no? Respond and adapt. Yes or no? Most scientists would say NO.

What are vaccinations The process of injecting a person with a harmless (weakened or dead) form of a virus to stimulate the immune system to produce cells and proteins that will destroy that type of virus.

Bacterial StructureFlagella Cell Membrane Ribosome Pili Chromosome Cell Wall

Survival/Reproduction Binary Fission: the process by which bacteria replicate chromosomes and the cell divides. Power of doubling (1 penny doubled 20 times) 1048576 cents or $10,485.76 Average bacteria doubles every 15-20 minutes Endospores Thick-walled reproductive structures that can resist heat, drought, and radiation, sometimes living centuries before breaking open.

Classifying Bacteria Archaebacteria (ancient) Methanogens: produce methane. Thermophiles: heated conditions Halophiles: salty conditions Eubacteria True Bacteria live in much less harsh environments than archebacteria. Many types and ways to classify. Shapes Spheres (cocci), rods (bacilli), spirals (spirilla), chains (streptococci), clusters (staphylococci). Cell Wall Composition Gram-positive (violet dye retains), Gram-negative(red dye). Nutrition (autotroph, heterotroph) Respiration (aerobes, anaerobes)

The Roles of Bacteria Decomposers. Breakdown dead material. Convert (fix) nitrogen into usable forms for plants. Symbiosis. mutualism. Bacteria can be harmful.

Common Diseases Caused by BacteriaPreventionPathogenDiseaseRegular dental hygieneProtection from tick bitesCurrent tetanus vaccinationVaccinationProper food-handling practicesMaintaining good healthClean water suppliesStreptococcus mutansBorrelia burgdorferiClostridium tetaniMycobacterium tuberculosisSalmonella enteritidisStreptococcus pneumoniaeVibrio choleraeTooth decayLyme diseaseTetanusTuberculosisSalmonella food poisoningPneumoniaCholera

Common Diseases Caused by VirusesDiseaseNucleic AcidType of VirusCancerCancer, AIDSRespiratory infectionsChickenpoxSmallpoxDNARNADNADNADNAOncogenic virusesRetrovirusAdenovirusesHerpesvirusesPoxviruses

Protists Common characteristic: EUKARYOTES Very diverse Three general categories: Animal-Like Protists Plantlike Protists Funguslike Protists

Plantlike Protists: Red, Brown, and Green AlgaeA.Red AlgaeB.Brown AlgaeC.Green Algae1.Unicellular Green Algae2.Colonial Green Algae3.Multicellular Green AlgaeFunguslike ProtistsA.Slime Molds1.Cellular Slime Molds2.Acellular Slime MoldsB.Water Molds

Fungi3 Common characteristics:-1. Cell wall are chitin. Same covering as insects.-2. Made of individual filaments, called hyphae. Tubes full of cytoplasm and nuclei.-3.Masses of hyphae combine to form the mycelium. This is the body of the fungus.

How does a fungus eat? Heterotrophs Diffusion: most fungi absorb small organic nutrients from their environment. Saprophytic: they absorb nutrients from dead or decaying organic matter.