Question

Carrier proteins release their cargo molecules ________. Carrier proteins release their cargo molecules ________. immediately after a phosphate has been removed from the carrier protein on the side of the membrane that has a lower concentration of the cargo molecule on the side of the membrane that has a higher concentration of the cargo molecule immediately after a phosphate has been added to the carrier protein

Answer 1

Answer:

The correct answer is:  on the side of the membrane that has a higher concentration of the cargo molecule immediately after a phosphate has been added to the carrier protein.

Explanation:

• A Carrier protein can be defined as an integral membrane protein that spans across the plasma membrane and is responsible for transporting molecules against the gradient of their concentration.
• A Carrier protein operates in the following manner:

1. In the unphosphorylated state, the carrier protein remains open to that side of the plasma membrane which has a low concentration of the solute molecules.
2. It binds to ATP (adenosine triphosphate) which causes it to bind to the solute molecules by increasing its affinity towards the solute molecules.
3. This is followed by the phosphorylation of the carrier protein with a kinase enzyme using the bound ATP (adenosine triphosphate).
4. This causes the carrier protein to have a conformational alteration that makes it open towards that side of the plasma membrane where the concentration of solute molecules is high.
5. The phosphorylated form of the carrier protein has a low affinity towards the solute molecules and so it releases the solute molecules in that side of the membrane where the concentration of solute molecules is high.
6. The phosphate group from the carrier protein is removed by a phosphatase.
7. Now, the de-phosphorylated carrier protein again comes back to its original conformation and faces that side of the plasma membrane where the concentration of solute molecules is low.