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
What are they made of?
Tiny, one cell thick filaments called hyphae
What is mycelium?
Tangled group of hyphae typically underground that digest and absorb food
What are club fungi?
Phylum basidiomycota, grow club-shaped fruiting bodies, and are what we commonly think of as mushrooms
What are sac fungi?
Phylum ascomycota, release spores from a structure called an ascus, ex truffles and yeasts
What are molds?
Phylum zygomycota, threadlike, produce spores from zygospores
What are imperfect fungi?
Phylum deuteromycota, fungi which have no sexual reproduction system, and are as such prone to extinction.
What structure produces spores in club fungi sexual reproduction?
Basidia, found on the gills on the underside of fruiting bodies
Step one of sexy reproduction for club fungi?
The haploid nuclei fuse together to make a diploid zygote
Step two?
Basidiospores form from those nuclei undergoing meiosis, and are haploid
Step three?
Basidiospores are released to germinate, and will form the primary mycelium
What’s up with the primary mycelia?
They only contain one mating type (+ or -)
Step four?
Primary mycelia fuse to create the secondary mycelium, whose cells contain both mating types
Final step?
The secondary mycelium eventually produces a fruiting body, and the cycle goes again
How do we refer to fungal nutrition types? (Similar to bacteria but not the same)
Sparophytic (eat dead stuff)
Parasitic (eat a host)
Symbiotic (live in harmony with other organisms)
How does yeast reproduce?
Budding, similar to binary fission but doesn’t always produce identical cells
What are two forms of asexual reproduction (for fungi)
Sometimes, hyphae break off from their fungus and grow a new mycelium, or fungi produce spores in a non sexual way
