| A | B |
|---|
| Pathogens | Agents that cause disease |
| Bacteriophages | Viruses that kill bacteria |
| Virus | A tiny, infectious particle consisting of a nucleic acid core surrounded by a protein coat (capsid) |
| Lytic cycle | Virus destroys the host cell (virulent) |
| Lysogenic cycle | Viral genome usually becomes integrated into the host bacterial DNA and is referred to as prophage, does not always destroy host cell (temperate) |
| Retroviruses | RNA viruses that have a DNA polymerase |
| Reverse transcriptase | Used to transcribe the RNA genome into a DNA intermediate |
| Viroid | Agent much smaller than a virus and has no protective protein coat and no associated proteins to assist in duplication |
| Prion | Proteinaceous infectious particle |
| Transmissible spongiform encephalopathies | Group of fatal degenerative brain diseases |
| Cocci | Spherical prokaryotes |
| Bacillus | Rod-shaped prokaryotes |
| Spirochete | Spiral-shaped, flexible |
| Spirillum | Spiral-shaped, rigid |
| Vibrio | Spirillum-shaped, comma |
| Peptidoglycan | Complex polymer that consists of two unusual types of sugars linked with short polypeptides |
| Gram-positive | Bacteria that absorb and retain crystal violet stain |
| Gram-negative | Bacteria that do not retain the stain when rinsed with alcohol |
| Plasmids | Small, circular fragments of DNA |
| Binary fission | Process in which one cell divides into two similar cells |
| Capsule | Slime layer that surrounds cell wall of bacteria |
| Pili | Hairlike appendages |
| Budding | Cell develops bulge that enlarges, matures, and eventually separates from mother cell |
| Fragmentation | Walls develop within the cell, which then separates into several new cells |
| Transformation | Fragments of DNA released by cell are taken in by another bacterial cell |
| Transduction | Phage carries bacterial genes from one bacterial cell into another |
| Conjugation | Two cells of different mating types come together, and genetic materialis transferred from one to the other |
| Endospores | Extremely durable cells formed by bacteria |
| Heterotrophs | Obtain energy and carbon atoms from the organic compounds of other organisms |
| Chemoheterotrophs | Get their carbon and energy from dead organic matter |
| Photoheterotrophs | Get their carbon from other organisms but use chlorophyll and other photosynthetic pigments to trap energy from sunlight |
| Autotrophs | Manufacture their own organic molecules from simple raw materials |
| Photoautotrophs | Use the energy from sunlight to synthesize organic compounds from carbon dioxide and other inorganic compounds |
| Chemoautotrophs | Use carbon dioxide as a carbon source, do not use sunlight as their energy source |
| Facultative anaerobes | Use oxygen for cellular respiration if it is available but can also carry on metabolism anaerobically when necessary |
| Obligate anaerobes | Carry out energy-yielding metabolism ONLY anaerobically |
| Methanogens | Produce methane gas from simple carbon compounds |
| Extreme Halophiles | Inhabit saturated salt solutions |
| Extreme thermophiles | Inhabit environments at temperatures higher than 100 degrees Celsius |
| Decomposers | Saprotrophs, Breaks down dead organic matter and wastes |
| Koch's postulates | Used to demonstrate that a specific pathogen causes specific disease symptoms |
| Exotoxins | Strong poisons that are either secreted from the cell or leak out when the bacterial cell is destroyed |
| Endotoxins | Not secreted by pathogens but are components of the cell walls of most Gram-negative bacteria |
| Bioremediation | Process in which a contaminated site is exposed to microorganisms that break down the toxins, leaving behind harmless metabolic byproducts |
