T10 - Prokaryotes Flashcards
what are the three defining characteristics of prokaryotic cells?
- single-celled
- lack a nucleus
- no organelles
Structural and functional adaptations
What is the advantage of cell walls for prokaryote survival?
- maintaining cell shape
- protecting cell
- prevents cell from bursting in unstable environments
What is the difference between bacterial cell walls and archaea cell walls in terms of their component?
Bacterial cell walls contain peptidoglycan
Archaea cell walls have polysaccharides but NOT peptidoglycan
Gram stain
a procedure that determines the composition of a bacteria’s cell wall
what is the composition of gram-positive bacteria
lots of peptidoglycan
what is the composition of a gram-negative bacteria?
less peptidoglycan
capsule
the protein/polysaccharide layers of many prokaryotes; forms biofilms
retains water, protection from macrophages
biofilms
produced by capsules; communities of cell sin a slimy extracellular matrix
fimbriae
hair-like appendaves that help adhere to substrates or other individuals in a colony
endospores
small, round, resting cells
ESCAPE POD
motile
the ability to move and respond within environment
pili
allows for DNA exchange in prokaryotes, longer than fimbriae
flagella
on cell surface, concentrated at one or both ends of cell
whips around for motility
taxes
abilities to move toward or away from a stimulus
What composes the simple DNA of prokeyotes?
a singular circular chromosome in a nucleoid OR plasmids
Plasmid
small rings of DNA
how do prokaryotes reproduce?
binary fission
T/F: binary fission results in two daughter cells, and is therefore secual reproduction.
FALSE. binary fission creates identical copies of itself, and is therefore asexual.
What three factors play into the speed of prokaryote reproduction?
- binary fission
- small cell sizes
- simple genomes
Wha three factores contribute to the genetic diversity of prokaryotes?
- rapid reproduction
- mutations
- genetic recombination
T/F: Mutation rates are high for prokaryotes because of their fragile DNA.
FALSE. Mutation rates are high due to the identical daughter cells of prokaryotes. This combined with rapid binary fission
Explain genetic recombination
the combination of DNA from two sources
Horizontal gene transfer
the genetic recombination between individuals from different species
What are the three methods of genetic recombination of prokaryotic DNA?
- Transformation
- Transduction
- Conjugation
Genetic Recombination
Transformation
foreign + prokaryote
Genetic Recombination
Transduction
bacteria + bacteriophages
bacteriophages
viruses that infect bacteria
Genetic Recombination
Conjugation
donor prokaryote + recipient prokaryote
pilus
singular to pili, the bridge that attaches to a recipient cell to transfer DNA via conjugation
What is the importance of plasmids in the survivability of a prokaryote?
antibiotic resistance
metabolism
can consist of anabolism and/or catabolism
anabolism
building up molecules
catabolism
breaking down molecules to release energy
phototrophs
energy from light
chemotrophs
energy from chemicals
autotrophs
carbon source is inorganic molecules
heterotroph
carbon source is organic substrate
explain the energy source, carbon source, and example organisms of photoautotrophs
light energy + CO2, HCO3, or related compound for carbon
photosynthetic prokaryotes, plants, and some protists
explain the energy source, carbon source, and example organisms of chemoautotrophs
inorganic chemicals for energy + CO2, HCO3, or related compound for carbon
unique to prokaryotes, found in many of them
explain the energy source, carbon source, and example organisms of photoheterotroph
light energy + organic compounds
unique to some extremophile prokaryotes
extremophile
adapted to extreme environments
explain the energy source, carbon source, and example organisms of chemoheterotrophs
organic compounds for energy + organic compounds for carbon
includes many prokaryotes, protists, fungi, and animals
obligate aerobes
require O2 for cellular respiration
obligate anaerobes
- poisoned by O2
- use fementation or anaerobic respiration
facultative anaerobes
can survive with or without O2
biological nitrogen fixation
the conversion of atmosphric nitrogen to ammonia
What are the 5 major bacterial groups?
- proteobacteria
- chlamydia
- cyanobacteria
- gram-positive bacteria
- spirochetes
Characterize the following sub-lineages of protobacteria:
alpha, gamma, epsilon
alpha: associated with eukaryotic hosts; evovled vial endosymbiosis to mitochondria
gamma and epsilon: pathogens
What arethe overarching characteristics of proteobacteria?
diverse, gram-negative
characteristics of chlamydias
intracellular paracites
characteristics of cyanobacteria
- only bacteria that produces oxygen
- evolveed via andosymbiosis to chloroplasts
characteristics of “gram-positive” bacteria
- only ones that stain gram-positive, but can include gram-negative taxa
- includes decomposers and pathogens
What are the three types of extremophiles that Archaea organisms can be?
- methanogens
- extreme halophiles
- extreme thermophiles
What are the ecological roles of prokaryotes?
- producing oxygen, fixing nitrogen
- decomposing and recycling chemical elements
