week 2 Flashcards
Nucleoid
genome + proteins (help organize the cell)
plasmids
small, circular DNA
- replicate independantly of genome
- multiple per cell
- many different functions
conjugation
antibiotic resistance
FtsZ
cell division
TubZ
plasmid segregation
MreB
cell shape (rod)
CreS
makes rods curved
caulobacter crescentus
MinD
prevents FtZ from polymerizing at poles
inclusions
no cell membrane
storage of nutrients
B-hydroxybutyrate
storage of carbon (inclusion = no membrane)
polyphosphate and sulfur inclusion
precipitated material = no membrane
storage of phosphate or sulfur
compartments: carboxysome
has a protein shell
hexagonal shaped
stores CO2 for rubisco to use
charged molecules can leave
CO2 cannot leave the compartment
compartments: gas vesicles
protein coating
long, narrow gas filled structure
structures: magnetosomes
has membrane coating!
- magnetic iron oxides
- allows bacteria to move along earths magnetic field lines
structures: endospores
produced when conditions are stressful
- non reproductive
-dormant
- very stable and resistant to chemicals, desication, antibiotics
role of plasma membrane
permeability layer
protein anchor
energy conservation
- proton pump
side chains in phospholipid bilayer
CH2 CH2 (NH3) COOH = phosphalitdylserine (common in e. coli)
undecaprenyl pyrophosphate
activated carrier molecule
integral membrane proteins
monotopic alpha helix
polytopic alpha helices
polytopic beta barrel
diffusion
permitted:
small hydrophobic molecules
O2, CO2
water
not permitted:
charged molecules
large hydrophilic molecules
osmosis
hypertonic: water wants to leave cell
hypotonic: water wants to enter cell
facilitated diffusion (uniport)
requires a protein carrier
does not require energy
goes along a concentration gradient
-ions, sugars, amino acids
simple transporters
against a concentration
gradient
- uses the energy of a proton going along their gradient
- symport and antiport
active transport
requires proton carrier
requires energy
ABC transporter = uses ATP
peptidogylcan structure
polysachharide backbone
- N-acetylglucosamine (G)
- N-Acetylmuramic acid (M)
+ short peptide cross links
teichoic acid
gram positive bacteria
made up of repeating ribitol unit
gram negative outer membrane
inner leaflet: phospholipids
outerleaflet : LPS layer
- O specific polysaccharide, core polysachharide, Lipid A (endotixin)
porins
contribute to making outer membrane more permeable than cytoplasmic membrane
mostly B - barrel proteins
