Lecture 17-18: Membrane Transport Proteins Flashcards
1
Q
P type ATPase quick description/examples
A
Self phosphorylates
SERCA
Na/K pump
2
Q
ABC transporter examples
A
ATP binding cassette
- MDR protein - monomer
- MsbA - homodimer
3
Q
V type pump
A
Uses ATP
4
Q
F type pump
A
Makes ATP
5
Q
A/Actuator domain
A
Links the cytosolic domains to the transmembrane domains
6
Q
N/Nucleotide binding domain
A
Binds ATP
7
Q
P/Phosphorylation domain
A
Accepts the phosphate from ATP
8
Q
SERCA steps
A
- E1 state, unphosphorylated, calcium ions bound
- ATP binds, calcium ions trapped
- ATP hydrolysis, self phosphorylation
- Eversion to E2 (open outside), Ca released
- Release of phosphate
- Eversion back to E1
9
Q
Na/K steps
A
E1, Na ions bound, ATP bound Na ions trapped ATP hydrolysis, self phosphorylation Eversion to E2, Na ions released Binding of K K ions trapped, release of Pi, ATP rebinding Eversion to E1 Release of K
10
Q
ABC transporter steps
A
- Empty transporter
- Small molecule binds and is trapped, ATP binding site affinity increases
- 2 ATPs bind causing eversion
- Small molecule is released
- ATP hydrolysis and release
11
Q
What type of transport does the Na/Glucose cotransporter use
A
Secondary active transport
12
Q
T or F: All secondary transporters are symporters
A
True
13
Q
Steps of lactose permease and type of transport
A
Secondary active transport
- Empty carrier, H+ binds and increases affinity for lactose
- Lactose binds
- Eversion
- Lactose released
- Deprotonation
- Eversion
14
Q
Factors effecting diffusion rates
A
Magnitude of concentration gradient Size of molecule Surface area/volume ratio (shape) Temperature Density of solvent Solubility of solute Distance to destination
15
Q
What happens to speed of diffusion if surface area/volume ratio is higher
A
Faster
