Bacteria and Archaea Flashcards
Prokaryotes
Unicellular (bacteria or archaea) cells that are built to last and evolve quickly
Differences between prokaryotes and eukaryotes?
Prokaryotes are smaller, have no membrane bound organelles, membrane is infolded, DNA is free flowing (not bound), small genome, very ancient
Infolded membrane
Creates space to separate cellular components
Cocci shape
Spherical
Bacilli shape
Rods
Spiral shape
Spiral
Peptidoglycan
Exclusive to bacterial cell walls; a network of sugar polymers cross linked by polypeptides
Fimbriae
Helps prokaryotes stick to each other to form colonies or to adhere to things
Flagella in prokaryotes
For movement; analogous w/ eukaryotes
Sex pilus
A type of fimbriae that serves as a mating bridge for DNA transfer
Taxis
Ability to move toward or away from a certain stimuli
Difference between prokaryotes and eukaryotes when it comes to reproduction and adaption?
Prokaryotes reproduce quickly and can divide every 1-3 hrs, have short generation times, and have more mutations
Three factors for genetic diversity in prokaryotes
Rapid reproduction, mutation, genetic recombination
Three types of genetic recombination
Transformation, transduction, and conjugation
Transformation
A prokaryotic cell takes up a random piece of DNA and incorporates it into it
Transduction
Movements of genes between bacteria by bacteriophages; viruses infecting bacteria and mixing it’s DNA with it
Conjugation
When genetic material is transferred via a sex pilus
Phototrophs
Organisms that get energy from light
Chemotrophs
Organisms that obtain energy from chemicals
Autotrophs
Organisms that require breaking down CO2 to form organic compounds
Heterotrophs
Organism that require nutrients to form organic compounds
Heterocytes
Photosynthetic cells and nitrogen fixing cells that exchange metabolic products; symbiosis between these two cells
Biofilms
Surface coating colonies held together by fimbriae
Symbiosis
An ecological relationship which two species live in close contact: a larger host and smaller symbiont
Mutualism
Both host and symbiont benefit
Commensalism
One organism benefits while the other is neither harmed or helped
Parasitism
An organism called a parasite harms but does not kill its host
Pathogens
Parasites that cause disease
Exotoxins
Cause disease even when the prokaryotes that produced them are gone
Endotoxins
Released when the bacteria dies and their cell wall breaks down
You’re inspecting organisms in a droplet of water and see a single-celled organism that has a flagellum, but seems to be moving pretty slow compared to the other organisms around it. On further inspection, you find that there are only proteins in the single-celled organisms’ cell walls. What type of organism do you think it is?
Archae (single celled organism + no peptidoglycan)
What do archaea have and lack?
They have polysaccharides and proteins but no peptidoglycan
What is the difference between autotrophs and heterotrophs?
Their source of carbon
