chap 4 Flashcards
passive diffusion
simple and facilitated diffusion; osmosis; no use atp
What conditions does a bacteria’s cytosol normally stay? and why?
Hypertonic to maintain osmotic pressure and cell wall structure
active transport
use atp and move against concentration gradient
in bacteria what does the cytoplasm contain?
proteins, ion, water, sugars and lipids
in bacteria what does the nucleoid contain?
it has haploids, of singular, circular, double banded dna
what are plasmids?
little pockets outside nucleoid that have dna with nonessential expression; can replication autonomously
how does protein synthesis work in bacteria?
in ribosomes, 30s+40s=70s
what can antibiotics target?
protein synthesis in ribosomes
metachromatic granules(voluntin)
stores inorganic phosphate
polysaccharide granules
stores glycogen, starch
lipid inclusions
store phb
sulfur granules
come from oxidation of h2s
lipid inclusions
phb
Magnetosomes
move towards n/s pole bc magnetic pull
move down away from o2(anaerobic/microaerophilic)
made of magnetite
chromatophores
folds in the membrane that contain things needed for photosynthesis
- photosynthetic pigments and enzymes
carboxysomes
contain rubisco for co2 fixation
- found in photochemoautotrophsis
gas vacuoles
stores o2, light, and nutrients for balance
What type of bacteria form endospores
bacillus and coltridium
what causes bacteria to form endospores
stress stimulants
endospores characteristics
-has dipicolinic acid(help w water loss) and ca+ that protect DNA
- 20% water removed during formation
- resistant to heating, freezing, radiation, chemicals, desiccation
- can go back to vegetative form w germination
endospore formation
- spore isolate new dna
- plasma membrane form around dna fr 1
- compartmentilization
- spore septum isolate new dna
- double membrane
- peptidoglycan forms around dna
- spore coat forms
- endospore is freed
endosymbiont theory
idea eukaryotes come from prokaryotes
- nucleoplasm engulfed aerobic bacteria and later evolves into mitochondria
- chloroplast: descendent of ancient cyanobacteria
nucleoplasm
ancestral eukaryote plasma membrane
evidence for endosymbiont theory
mitochondria and chloroplast have:
- same size as bacteria
- circular DNA
- ribosome like bacteria
- can self duplicate
- affected by antibiotics that inhibit bacteria
characteristics of prokaryotes
- circular dna
- nucleoid region
- not complex/strong cytoskeleton
- spilt through binary fission
- no organelles
- domain bacteria and archea
characteristics of eukaryotes
- multiple, linear dna
- nucleus
- complex cytoskeleton
- divide through mitosis and meiosis
- membrane-bound orgnaelles
- cell walls have cellulose
- domain eukareya
glycocalyx
polysaccharide layer on outside of cell
- in pathogens call for resistance to phagocytosis
two types: capsule and slime layer
- capsule; tight and more organized
- slime layer ; looser
flagella
for motility via rotary motion
3 parts:
- filament, monomers of flagellin that wrap around hollow core
- hook, attach filament to basal body
- Basal body, attach flagella to membrane and cell wall
What is the difference between runs and tumbles?
- runs are towards taxis and is constant
- tumbles are random changes in direction towards a taxis(interrupts runs)
frequency of runs and tumble meaning
- higher amount of runs means cell found taxis and is moving towards it
- high tumble = cell looking for taxis; tumble direction will be random
axial filaments
- only in spirochetes
- protein fibers around pole of cell
- make corkscrew motion
fimbriae
- few on cells
- mainly used for attachment to surfaces
pilli
- longer than fimbriae
- has sex pilus(where it attaches to other cells and insert DNA)
- provide twitching and gliding motility
what is the bacterial cell wall made of?
peptidoglycan; made up of repeating nam and nag connected with cross bridges
gram-positive characteristics and make up
- thick peptidoglycan with teichoic acids
- lipoteichoic acid - connect with plasma membrane
- wall teichoic acid - like to peptidoglycan
- teichoic acids - negative charge
- stain purple
gram-negative characteristics and make up
- inner and outer membrane
- outer membrane is barrier for antibiotic and other things more than gram pos
- lps
- o polysaccharide - for identification
- core polysaccharide
- lipid a - releases endotoxin
- thin layer peptidoglycan
- periplasmic space - space btwn inner and outer membrane
- stain red
mycoplasma
smallest bacteria, no cell wall
what is the cell wall of archaea made of?
pseudomurien
mycobacteria
- have waxy lipid by mycolic acids
- protection against host; basis for acid staining
steps for simple stain
- stain with iodine
- wash w water
- wash w ethenol
- dye w red
