biology
Prokaryotic- organism whose cells lack a nucleus and other organelles Gram-positive- bacteria surrounded by layers of peptidoglycan but lack outer membrane Gram-negative- bacteria surrounded by thin peptidoglycan cell wall, which is surrounded by outer membrane Bacillus- aerobic, sporulating, rod-shaped bacteria that are common in nature. Cocci- spherical or round or oval. Spirilla- curved shaped bacteria which can range from gently curved to corkscrew spiral. Autotrophic- an organism that can produce its own food using light, water, carbon dioxide or other chemicals. Heterotrophic- an organism that eats other plants or animals for energy and nutrients. Binary fission- asexual reproduction by separation of the body into two new bodies. Endospore formation- that bacterium divides within its cell wall. One side then engulfs the other. Conjugation- the process which bacterium transfers genetic material to another through direct contact. minimal disruption of targets cellular envelope and ability to transfer relatively large amounts of genetic material. Transduction- the process which a virus transfers genetic material from one bacterium to another. Transformation- the process which an organism acquires exogenous DNA. How bacteria helps humans- help degrade the food we eat, makes nutrients available to us and neutralize toxins, defence against infections by protecting colonized surfaces from invading pathogens. How bacteria hurts humans- responsible for food spoilage, cause allergies and chronic inflammation. Microbiome- is the community of microorganisms that can usually be found living together in any given habitat. Decomposing- the process which the complex organic substances breakdown into simpler substances by the action of microorganism. Nitrogen fixation- the chemical processes which atmospheric nitrogen is assimilated into organic compounds. Examples of bacterial diseases- Tuberculosis, anthrax, tetanus, pneumonia, botulism. Antibiotic resistance & superbugs- bacteria that are tough enough to survive the drug will have a chance to grow and quickly multiply. Antibiotics- work by blocking vital processes in bacteria, this helps the body’s natural immune system to fight infection. Environments for bacteria- warm, moist, protein rich environments that is pH neutral or slightly acidic. Sterilization- destroys or eliminates all forms of microbial life (high pressure steam, dry heat, chemical sterilants. Vaccine- a substance used to stimulate immunity to a particular infectious disease or pathogen. How viral infections spread- from other people: coughing or close contact or surfaces infected. Lytic cycles- the virus introduces genome into a host cell and initiates replication by hijacking the host’s cellular machinery to make new copies of the virus. Lysogenic cycles-a viral reproductive stage where the virus’s DNA is being replicated by using. host cells DNA. What type of cells are bacteria?- they are prokaryotes. obligate aerobe- organism that requires oxygen to grow. Obligate anaerobe- organisms that can now and survive only in absence of oxygen. Facultative- bacteria that can grow in both the presence or absence of oxygen. Foods made with help of bacteria- bread, beer, wine, vinegar, cheese. Anaerobic bacteria can survive without oxygen. The ability of viruses to jump from one species to infect a new species shows that viruses infect new species when their original hosts become immune. FALSE:viruses infect new species when they MUTATE to be able to attach to a new cell type. Lytic viruses insert their DNA into a host cell’s DNA making a “prophage”. After a while the prophage is copied and makes copies of the virus. A lysogenic virus takes over a host cell uses the organelles to copy itself and then the many copies of the virus burst open the host cell and are released into the rest of the body. FALSE: Switch lytic and lysogenic. All bacteria require oxygen to survive. FALSE: Some bacteria require oxygen (obligate aerobes), some are killed by oxygen (obligate anaerobes), so can live with only a little oxygen (facultative anaerobes). Gram negative bacteria are different from gram positive bacteria because gram positive bacteria have an additional plasmid. FALSE: gram positive bacteria have an additional layer of peptidoglycan. Viral specificity means that any virus can infect any type of cell. FALSE: viruses are specific to a certain cell type – one virus can only infect one type of cell. Bacteria are prokaryotes and viruses are eukaryotes. FALSE: bacteria ARE prokaryotes, but viruses are not eukaryotes. They do not have a classification as they are not living. If antimicrobial disks containing chemicals and antibiotics are placed on a petri dish with a lawn of bacteria, the zone of inhibition is the area around each disk where bacteria are growing. FALSE: the zone of inhibition is the area where bacteria do NOT grow (they are killed by the antimicrobial). Superbugs are formed when bacteria mutate to become resistant to antibiotics. TRUE. Bacterial growth can be increased with refrigeration, salt, and very high temperatures. FALSE: bacterial growth is decreased with all of these things. To increase bacterial growth, grow them at their optimal temperature and with the nutrients they need to grow.