Chapter 27 Bacteria and Archaea Flashcards
What are the two domains of prokaryotes?
Archaea and Bacteria
Are prokaryotes multicellular or unicellular?
Unicellular that can form colonies
What the 3 common shapes of prokaryotes?
spheres (cocci)
rods (bacilli)
spirals
What are bacterial cell walls made up of?
What are archaean cell walls made up of?
Peptidoglycan - Bacteria
Polysaccharides and Proteins - Archaean
What is an important feature of the prokaryotic?
It’s cell wall
What is a gram stain
Used by scientists to classify bacteria by cell wall composition
gram positive bacteria
have simpler walls with a large amount of peptidoglycan
gram negative bacteria
have less peptidoglycan and has an outer membrane that can be toxic
Which gram bacteria is most likely to be antibiotic resistant?
gram negative bacteria because most antibiotics target peptidoglycan and it doesn’t have much of this
What is a capsule?
A polysaccharide or protein layer that covers many prokaryotes
Taxis
Ability to move toward or away from a stimulus
Chemotaxis
Movement toward of away from chemical stimulus
what is a bacterial flagella composed of?
- motor
- hook
- filament
What are plasmids?
Smaller rings of dna that some species of bacteria have
what is a nucleoid region?
where circular DNA chromosome is located; not surrounded by a membrane
What do prokaryotic cells lack?
They lack complex compartmentalization
What are key features of the prokaryotic reproduction?
- they’re small
- reproduction by binary fission
- have short generation times
What 3 factors contribute to genetic diversity in prokaryotes?
- Mutation
- rapid reproduction
- genetic recombination
Genetic Recombination
Combining of DNA from 2 sources, contributes to diversity
Transformation
Prokaryotic cells can take up and incorporate foreign DNA from the surrounding environment
Transductions
Movement of genes b/w bacteria by bacteriophages
Conjugation
Process where genetic material is transferred b/w prokaryotic cells
What are the 3 ways prokaryotic DNA from different individuals can be brought together?
- transformation
- transduction
- conjugation
What is the F-factor?
A piece of DNA that’s required for the production of pili
Connection between F plasmid and conjugation?
During conjugation, cells that has f plasmid is a DNA donor and those without f plasmid is a DNA recipient
What is a R plasmid?
It carries the genes for antibiotic resistance
Bacteria that has r plasmids cannot be killed with antibiotics
What are the 4 ways prokaryotes are organized by how they obtain energy and carbon?
- Autotrophs: requires CO2 as a carbon source
- Phototrophs: Obtains energy from light
- Heterotrophs: Obtains energy from organic nutients
-Chemotrophs: Obtains energy from chemical reactions
What are the 4 major modes of nutrition?
- Photoautotrophy: Makes own food but needs sunlight
- Chemoautotrophy: Doesn’t need sunlight but needs inorganic chemicals
- Photoheterotrophy: Needs sunlight and nutrients
- Chemoheterotrophy: Needs nutrients and chemicals
What are the 3 roles of oxygen in metabolism?
- Oblique Aerobes: Requires O2 for cellular respirations
- Oblique Anaerobes: Doesn’t need O2 for respirations
- Facultative Anaerobes: Can survive with or without O2
What are the 3 extreme archaeans?
extremophiles: Archaea that lives in extreme environments
extreme halophiles: archaea that live in saline environments
extreme thermophiles: archaea that live in very hot environments
What are methanogens?
Lives in swamps and marshes, and produce methane as a waste product
What is commensalism?
One organism benefits while the other doesn’t benefit nor is harmed
What is mutualism?
Both symbiotic organisms benefit
What is parasitism?
Parasite harms but doesn’t kill its host
What is exotoxins?
Toxins secreted and cause disease without the present of the prokaryote
What are endotoxins?
Toxins released only when the bacteria dies and the cell wall breaks down
Proteobacteria?
Gram-negative bacteria that includes photoautotrophs, chemoautotrophs, and heterotrophs. Some are anaerobic while others are aerobic
- All include a greek name along with proteobacteria
What is cyanobacteria?
Photoautotrophs that generates O2.
What is spirochetes?
Bacteria that are helical heterotrophs
examples: causes syphilis
