prokaryotes Flashcards
what is LUCA predicted to be
prokaryote
what is a group of prokaryotes called
paraphyletic group
do prokaryotes have a plasma membrane
yes
what is the cytosol
content of cell within plasma membrane
what is the cytosol
internal fluid containing organic molecules, proteins, metabolic waste, etc.
what is the nucleoid
region not enclosed by membrane
what is fimbriae
short appendages helping bacteria to adhere to substrate
what is the capsule
dense layer of polusaccharide surrounding cell wall
–> protects cell
(T/F) Prokaryotes have organelles
F
do bacteria have histones?
No, but are present in some archaea
histones: proteins that bind to DNA
what are flagellum
long cellular appendages specialized for locomotion
what is gram classification
bacteria is classed according to structure of cell wall into gram(+) and gram (-)
what is gram(+) vs. gram (-)
gram (-) more resistant to antibodies
–> outer membrane blocks water-soluble antibiotics
what is a microbiome
community of microorganisms that live on/in human body
what is commensalism
symbiotic relationship where one organism benefits, other is not helped/harmed
photoautotroph vs photoheterotroph
photoautotroph: able to make its own food from inorganic compounds
photoheterotroph: use light for energy, but cannot make its own good from CO2
chemoautotrph vs chemoheterotroph
chemoautotroph: organisms that gain food from chemical compounds (CO2)
chemoheterotroph: cannot create own food
what do food webs rely on photoautotrophs for
- absorbing energy from outside ecosystem (light)
–> convert CO2 into sugars, produce O2 - assimilating minterals into biomass that is pass on
–> recycling of C,H,O,N,P
what are the primary producers
photoautotrophs
what are decomposers
absorb/convert nutrients from nonliving organis materials into inorganic forms
what is asexual reproduction
reproduction by binary fission
what is binary fission
doubling in size and simple division in half
–> replicates genome
what are the 4 phases of asexual reproduction
1) lag phase: synthesis of components required for growth
2) log phase: rapid growth through cell divisions by factor of 2^n
3) stationary phase: population stops to grow (lack of nutrients, oxygen, etc)
4) death phase: exponential loss of viability due to lack of nutrients, oxygen, prolonged exposure to waste
what is an antibiotic
molecule that kills growth of bacteria
how can bacteria evolve resistance to antibiotics
- mutations alter genes
- resistance transmitted vertically through inheritance
- only resistant strains can grow
what is conjugation
1) 2 cells temporarily joined through a pilus (hair-like structure) that draws receiver cell closer)
2) establishment of mating bridge
3) plasmid can be transferred from donor to receiver
what is the F factor
fertility factor contains geners required to make the pilus
selfish DNA: enhances its own transmission
what is the R plasmid
resistance plasmid that contains antibiotic resistance
–> genes carries by R plasmid can spread through conjugation
what is transduction
bacteria exchange DNA through virus called bacteriophage (infects bacteria)
–> phage represents intermediate between donor/recipient cell
what is transformation
bacteria release DNA after death which can be taken up by another bacteria
–> occurs naturally when bacteria recognizes a foreign DNA
