Virus, Bacteria, Fungi Flashcards
What are the three layers of the outside of a bacterium?
Cell membrane, cell wall, and sometimes capsule (sticky stuff)
What are the three bacteria shapes?
Bacillus, coccus, and spirillum
Bacteria may form what after cell division?
Pairs, chains, or colonies
What are the prefixes for those?
Diplo- Strepto- and Staphylo-
What are the walls of bacterial cells made of?
Petidoglycan! (Archaebacteria are the ones without it)
Bacteria sometimes have an extra layer outside the cell wall, what is it called and what’s its purpose?
Capsule, it’s a sticky layer used to help bacteria stay stuck to hosts or other bacteria
Bacteria are prokaryotic, so they don’t have a defined nucleus. What is their DNA like?
Small rings called plasmids
What structures do bacteria have inside their cells?
Plasmids, cytoplasm, ribosomes, and the membrane
How do bacteria move?
Bacteria move using their flagella, a thin wiggly thing that helps them glide, or wiggle
What are the short, hair-like structures on the outside of bacteria called?
Pili, they’re proteins that help bacteria stick to surfaces, and are kinda like the peen in conjugation
What do gram positive bacteria do?
Retain the stain crystal-violet, and appear purple under the microscope
What is done to gram negative bacteria?
They’re treated with alcohol, then are treated with safranin, which turns them pink or reddish
How do bacteria reproduce?
Sexually via conjugation, or asexually via binary fission. Binary fission results in two identical cells, while conjugation involves the transfer of genetic info via pili
What are the types of autotrophic bacteria?
Photoautotrophs: like plants
Chemotautotrophs: react inorganic matter to gain energy
What are the types of heterotrophic bacteria?
Saprobes: eat dead stuff
Parasites: feed on their host
Mutualists: live in harmony with another organism
What is an obligate aerobe?
An organism that requires oxygen to live
What is an obligate anaerobe?
And organism that dies in the presence of oxygen
What is a facultative anaerobe?
An organism that doesn’t need oxygen, but also isn’t killed by it
What is a virus?
Non-cellular particle made of genetic material and proteins
Basic viral structure?
Protein coat called capsid encloses nucleic acid core containing RNA or DNA
What are the three viral structure types?
Helical, polyhedral, and complex
Briefly explain the lytic cycle
The virus attaches itself to the host cell, then injects its nucleic acid into it. This nucleic acid takes over, causing the cell to replicate the viral genetic material instead of its own. The viral genetic material is assembled into viral particles, which eventually cause the host cell to lyse, releasing the new viral particles
Explain the lysogenic cycle
The virus attaches itself to the host, and injects its nucleic acid. That DNA is then incorporated into the host DNA, creating a prophage. The virus is then replicated with the host cell indefinitely, causing no symptoms but spreading throughout the body. When the immune system is suppressed, the virus becomes active and starts the lytic cycle.
What are fungi?
Eukaryotic, absorptive heterotrophs with cell walls made of chitin. They’re multicellular, except for yeast