Chapter 25- Bacteria and Archaea
Mutualism
A symbiotic relationship in which both partners benefit
Phototrophs
Capture energy from light
Obligate anaerobes
Carry on anaerobic respiration; they respire with terminal electron acceptors other than oxygen, such as sulfate, iron, or nitrate
Most prokaryotes have a ______ surrounding the plasma membrane and provides a rigid framework that supports the cell and helps it maintain shape
Cell wall
Chemoheterotrophs
Depend on organic molecules for both carbon and energy sources; most are free-living decomposers that obtain carbon/energy from dead organic matter
What bacterial process is involved in the production of cheese and yogurt?
Fermentation
Transformation
When a prokaryotic cell takes up foreign DNA
Commensalism
A symbiotic relationship where one partner benefits and the other is neither harmed nor benefited
How do some bacteria respond to adverse environmental conditions?
Bacteria form endospores
What prokaryote method of reproduction does not result in genetic variation?
Binary fission
Gram-positive bacteria
Cell walls are very thick and consist primarily of peptidoglycan; absorbs and retains crystal violet stain in lab
What are the different shapes of prokaryotes?
Cocci (round), bacilli (rod-shaped), spirochete (spiral, flexible), spirillum (spiral, rigid), vibrio (spirillum shaped like a comma)
Heterotrophs
Obtain carbon atoms from the organic compounds of other organisms
What is missing in the cell walls of archaea but not bacteria?
Peptidoglycan
How do prokaryotes benefit us?
They inhabit soil, produce antibiotics, are used in bioremediation (process of using microorganisms to detoxify/remove oil, gas, and other pollutants/ toxic chemicals from the environment)
Horizontal gene transfer
When an organism (or virus) transfers genetic material to another organism that is not its offspring
A bacterium that uses the oxidation of inorganic compounds to provide energy for manufacturing nutritious organic compounds is a
chemoautotroph
What are spherical shaped bacteria called?
cocci
Prokaryotic cells do/don't have a nucleus or other membrane-bound organelles
Don't
Photoheterotrophs
Obtain their carbon from other organisms but use chlorophyll and other photosynthetic pigments to capture energy from sunlight
What are the 5 subgroups of bacteria
Proteobacteria, gram-positive, Cyanobacteria, chlamydias, spirochetes
Plasmids
Smaller circular fragments of DNA
What is the purpose of the sex pili?
To transmit DNA between bacteria
Symbiosis
An intimate relationship between two or more species
How do bacteria move?
By means of a rotating flagella
Binary fission
Equal division of a prokaryotic cell into two (asexual reproduction)
Describe the diverse types of Archaea living in extreme and more moderate environments
Extreme halophiles: salt loving; extreme thermophiles: heat loving; methanogens: live in anaerobic environments, give off methane as a waste product; moderate environments: in the ocean
Sex pili
Important in transmitting DNA between bacteria
Flagellum (flagella) function
Movement
What type of symbiotic relationship occurs between a ruminant and the bacteria in its digestive tract?
Mutualism
Peptidoglycan
Present in bacterial cell wall, absent in archaeology cell wall
Nitrogen fixation
Reduction of nitrogen in the atmosphere to ammonia
Nitrification
The conversion of ammonia to nitrate by certain bacteria in the soil
Although there is no membrane bound nucleus, prokaryotes have a nuclear area called ____
The nucleoid, which contains DNA
Conjugation
Two cells of different mating types come together and genetic material is transferred from one to the other
Fimbrae function
attachment
Endospore
A durable cell produced in stressful environments by the process of binary fission, and will then germinate when conditions are favorable again
Transduction
A phage carries bacterial or archaeal genes from one bacterial or archaeal cell into another
Endotoxins
A poisonous substance in the cell walls of gram-negative bacteria
Exotoxins
A poisonous substance released by certain bacteria
Parasitism
A symbiotic relationship where the parter that benefits lives in/on the partner that is harmed
Biofilm
A community of microorganisms attached to a surface
Bacterial chemoautotrophs use organic chemicals as an energy source (true/false)
False
Chemotrophs
Obtain energy from chemical compounds
Genes for the resistance to antibiotics are usually located _____.
On plasmids
Aerobic
Require oxygen for cellular respiration
Gene transfer
Results in genetic recombination; transformation, transduction, conjugation
What is a chain of round bacteria called?
Streptococci
Capsule
Surrounds cell wall; adds protection against phagocytosis (engulfment from other microorganisms)
Vertical gene transfer
Transfer of genetic material from parent to offspring
Chemoautotrophs
Use carbon dioxide as a carbon source, but do not use sunlight as their energy source; obtain energy by oxidizing inorganic chemical substances
Autotrophs
Use inorganic compounds as a source of carbon for manufacturing their organic molecules
Facultative anaerobes
Use oxygen for cellular respiration if it is available but can carry on metabolism anaerobically when necessary
Photoautotrophs
Use the energy from sunlight to synthesize organic compounds from carbon dioxide and other inorganic compounds
Budding
Asexual reproduction where a cell develops a bulge, or bud, that enlarges, matures, and eventually separates from the mother cell
Fragmentation
Asexual reproduction where walls develop within a cell which then separates into several new cells
The ____ keeps the cell from bursting under hypotonic conditions
Cell wall
Gram-negative bacteria
Cell walls contain 2 layers: a thin peptidoglycan layer and a thick outer membrane (resembling plasma membrane but contains polysaccharides bonded to lipids; does not retain the stain when rinsed with alcohol; antibiotics will not help with infections in this case (cold/flu)
