Chapter 4: 4.5 Membrane Protein Function Overview Flashcards
Where are membrane proteins found?
On the surface, embedded, or spanning the lipid bi-layer of the membrane
———– ——– are found on the protions interacting with the —– ——–
- Hydrophobic residues
- Lipid bi-layer
How are membrane proteins classified?
By function (ie. channels, transporters, receptors, and enzymes)
Describe:
Transporters
Move substrates from a high concentration to a low concentration across the plasma membrane
What is high concentration vs. low concentration of substrates between the plasma membrane known as?
Substrate gradient
How do transporters recognize their corresponding substrate?
Transporters have very specific binding sites
* Used to recognize their corresponding substrate
Transporters transition from an —- phase to a —— phase during transport
- Open
- Closed
Define:
Pumps/Active transport
Moves substrates against their concentration gradient
True or False:
Pumps/Active transport requires external energy
True
What is the external energy used by pumps/active transport?
ATP
What happens to the protein pumps in active transport?
The external energy (ATP) causes a conformational change of the protein
True or False:
Things are transported directly across the plasma membrane
False, nothing is transported across the plasma membrane
If nothing is transported across the plasma membrane:
How do signals get transported across the cell?
The ligand binding to the receptor on the outside of the membrane results in a signal to be generated on the internal side of the membrane
Can receptor proteins span the proteins once?
Yes, it can span the membrane once or multiple times
How are different classes of receptor proteins separated?
- Structure
- Method of signal transmission
