Bacteria and Virus

Virus: a non-living particle made of proteins, nucleic acids, and sometimes lipids; can only reproduce by infecting cells

Capsid: protein coat surrounding a virus, binds to receptor proteins to trick the cell and let the virus in

Bacteriophage: viruses that infect bacteria

Viral infection: once inside a cell, a virus uses genetic information to reproduce

  • Lytic infection: a virus enters a bacterial cell and makes copies of itself, causing the cell to burst

  • Lysogenic infection: when a host cell isn’t immediately taken over, viral DNA is replicated with host DNA and doesn’t damage host

Prophage: bacteriophage DNA embedded in host’s DNA

Retrovirus: genetic information copied RNA→DNA

Parasite: ALL viruses, depend entirely on other living organisms

Prokaryotes: unicellular organisms that lack a nucleus, bacteria or archaea

  • Bacteria: almost everywhere, larger of 2 domains, wide range of organisms

  • Archaea: live in harsh environments, similar to bacteria but lack peptidoglycan and have different DNA

Bacilli: Rods

Cocci: spheres

Spirilla: spiral

Binary fission: a prokaryote growing to 2x its size, then splitting into two identical cells

Endospore: thick internal wall that encloses DNA and some cytoplasm

Anaerobes: prokaryotes that thrive in oxygen-free environments

Mutation: random changes in DNA

Conjugation: a hollow bridge forms between two bacterial cells, genetic material moves from one to another

Decomposers: break down dead organisms to maintain equilibrium

Producers: create food and biomass, first link in food chains

Nitrogen fixers: some producers convert Nitrogen (N2) into useful forms (ammonia)

Pathogens: disease-causing agents

Controlling bacteria methods: physical removal, disinfectants, food storage, food processing, heat sterilization

Vaccine: a preparation of weakened/killed pathogens, or inactivated toxins

Antibiotics: block growth and reproduction of bacteria

Emerging disease: an unknown or harder to control disease

Superbug: a bacteria that is resistant to multiple antibiotics

Prions: protein infectious particles