Membrane basics Flashcards
1
Q
what is GTP used for?
A
- translation
- nuclear import
2
Q
what is the structure of nucleotide-sugars?
A
- last phosphate replaced with sugar eg ribose
3
Q
what does amphipathic mean?
A
- spontaneously forms bilayers eg phospholipids
4
Q
what are the two types of proteins in membranes? what are the differences?
A
1- INTEGRAL (span entire p.b membrane)
- can pass through the memb once or multiple times
- more PERMANENTLY attached to memb
- covalently attached to an embedded LIPID via OLIGOSACCHARIDE LINKER
2- PERIPHERAL (don’t span entire memb)
- more loosely attached to memb
- interact w/ embedded protein
- interact w/ POLAR HEADS of phospholipid bilayer
5
Q
key principles of diffusion?
A
- only small/non-polar molecules
- DOWN conc grad
- ENERGETICALLY FAVOURABLE (no energy needed)
- spontaneous until equilibrium reached
6
Q
key principles of facilitated diffusion?
A
- ENERGETICALLY FAVOURABLE (no energy needed)
- spontaneous until equilibrium reached
- transport of HYDROPHILIC mol and IONS that need CHANNELS (fast) or CARRIERS (slow)
- channels may be gated
7
Q
key principles of active transport?
A
- AGAINST GRAD
- energetically unfavourable
- transporters linked to ENERGY SOURCE to allow transport
8
Q
what is SYMPORT active trans?
A
type of COUPLED transport (secondary active trans) where TWO MOLECULES are transported in together
9
Q
what is ANTIPORT active trans?
A
type of COUPLED transport (secondary active trans) where one molecule is transported IN and the other one OUT.
