Bacterial Transport Flashcards
What is the structure of a phospholipid?
glycerol, 2 ester linked fatty acids, phosphoryl head group
What do planar lipid molecules add to the membrane?
strength (cholesterol)
Bacteria regulate membrane (blank) and rigidity by varying the (blank) of these lipids.
fluidity, abundance
What are the 2 types of Archea membrane side structures?
diethers and tetraethers
Describe a dietether.
2 chains ether linked to glycerol that form bilayers in the membrane
Describe a tetraether.
very long chains linked at ether end that form a monolayer membrane which is more stable
What are some functions of membrane proteins?
structural support, ion transport, energy regeneration, detection of environmental signals
What are the 3 types of transport across the CM?
1) no expenditure of energy (diffusion, facilitated proteins)
2) expenditure of energy (export against a concentration gradient, active transport)
3) osmosis (movement of water molecules)
What diffusion moves uncharged molecules?
simple
What diffusion moves molecules through a channel-forming protein?
facilitated
What are coupled substrate transport systems?
they export 2 substances at the same time, energy is released by 1 substrate moving down the gradient fuels a different solute up the gradient
Where are ABC transporters found?
in all 3 domains of life
What ABC transporter transports nutrients?
uptake
What ABC t efflux transporter has mutidrug efflux pumps?
Efflux
What do phospholipids vary with?
they vary with composition and charge of heads, abundance of phospholipids in response to stress, composition of side chains
What is membrane fluidity essential for?
CM stability and protein function
Membranes have (blank) of high and low fluidity.
regions
Why do saturated lips increase rigidity?
they melt at higher temperatures
Why do unsaturated lipids increase fluidity?
they melt at lower temperature
