Chapter 20 Flashcards
What are the two kingdoms of prokaryotes? Which one is more closely related to eukaryotes?
1 Archaebacteria (closer to eukaryotes) 2 Eubacteria
What are the differences between the 2 prokaryotic kingdoms?
Eubacteria has peptidoglycan in cell walls, Archaebacteria does not
Have different membrane lipids
What are the shapes of prokaryotes?
1 bacillus- rod shaped
2 Coccus- sphere shaped
3 Spirillum- spiral shaped
What can prokaryotes do in the environment?
1 decompose
2 nitrogen fixing (N2 gas to nitrates for plants to use)
3 Producers
What do humans use prokaryotes for?
1 food production (yogurt)
2 making medicines
3 chemical lab processes
What characteristics are used to identify prokaryotes?
1 movement
2 shape
3 how they use energy
4 how they obtain energy
What is a photoautotroph, photoheterotroph, and chemoautotroph?
See notes
In what ways do prokaryotes move?
Some don’t move
Flagella
Gliding on “slime”
“Snaking” motion
What is binary fission?
Asexual reproduction
What is conjugation? How does it increase genetic diversity?
hollow bridge forms between 2 bacteria and genes move from one to the other to transfer genetic info
new genetic combinations are made from mixing DNA between 2 cells
the largest source of evolution in prokaryotes
Mutation
What is an endospore and when would a prokaryote make an endospore?
A thick wall encasing the DNA of a prokaryote. The cell can go into this dormancy period to get through unfavorable conditions (lack of nutrients, water, etc.)
What is a virus? What are the parts of a virus?
A nonliving particle that infects cells
DNA/RNA
Capsid (protein coat)
Sometimes lipids
What type of molecules are capsids (of viruses) made of? What is its function?
Protein- to help bind to the host cell’s surface
What are bacteriophages?
Viruses that infect bacteria cells
Describe the cycle of a virus that causes lytic infections.
Viral DNA injected and immediately starts taking over host cell. Host cell makes viral particles (from instructions in virus DNA) and eventually cell bursts open to release more viruses into the environment
page 577
Describe the cycle of a virus that causes lysogenic infections
Viral DNA is embedded into host cell DNA and lays dormant for a period of time (page 577)
What is a prophage?
Viral DNA to be inserted into host DNA (during lysogenic infection)
What is a retrovirus?
A virus that transcribes the viral RNA into DNA before embedding it in the host cell DNA
What characteristics of life do viruses meet/not meet?
DO- reproduce (in host cell)
Have Dna, evolve
DO NOT- obtain and use energy grow and develop respond to environment Maintain homeostasis
Not made of cells
What are pathogens?
Disease causing agents (bacteria, viruses, and prions)
How do bacteria cause disease?
1 relesase toxins (which basically poisons your cells)
2 destroy cells (breaks down cells and uses as food source)
How do viruses cause disease?
1 disrupt cell processes
2 destroy cell
How do you prevent and treat bacteria diseases? Viral diseases?
get picture from google drive
Why do plant viruses have a hard time infecting cells?
Because of the rigid cell wall. They usually enter through damaged areas (like where insects have been eating or birds pecking)
How can you control bacterial growth and reproduction?
1 store food at low temps- slows growth
2 disinfect items- chemicals kill bacteria
3 sterilize items- heat kill bacteria
What are emerging diseases and why are they a bigger concern today than in the past?
an unknown disease that appears in a population for the first time or becomes harder to control
more international travel
climate change expands regions where disease is found
more human animal contact with cutting down rainforests (diseases jump from animals to humans)
bacteria gain resistance to our medicines through evolution
What are prions? How do they cause disease?
Mis-folded proteins that can accumulate in cells and disrupt normal processes
