Active transport

Question 1

define active transport.

Answer 1

Active ransport, involves moving particles against their concentration gradient, through a transport protein which spans the membrane. It requires ATP from respiration.

Question 2

Explain how one particle can be transported using active transport.

Answer 2

1. The desire molecule, binds to a binding site on the part of the transport protein that it outside of the cell.
2. ATP binds to the second binding site, located on the part of the transport protein that is inside of the cell.
   -The ATP is then broken down into ADP and a phosphate ion, by a hydrolisis reaction.
3. When the phosphate ion, and the desired particle are binded at the same time, they trigger a series of reactions that causes the shape of the transport protein to change.
4. The particle is then forced through the transport protein, followed by the release of the phosphate ion
   - Now

-The transport protein now reverts back to its original shape.

Question 3

describe how you can actively transport 2 particles.

Answer 3

step 1: same steps as in transporting one particle.
-hoever, when desired particle is forced through the transport protein, it reveals another binding site, for another desired particle.

step 2: The second particle binds, and then gets pushed out.

In this way, we can ensure that 2 particles are being actively transported at the same time.

Question 4

What type of transport proteins, does facillitated diffusion use?

Answer 4

Both channel, and carrier proteins.

Question 5

what types of transport proteins, does active transport use?

Answer 5

Only uses CARRIER proteins.

NOT channel proteins.

Question 6

Describe how CO-transport of glucose, and amino acids occurs in the lument of the ileum.

Answer 6

step 1: Sodium ions are actively transported out of the sodium potassium ion pump, out of the epithelial cell, into the blood.
-It does this through active transport in a carrier protein.
step 2: This reduces the sodium ion concentration in the epithelial cell, when compared to that of the lumen.
step 3: sodium ions now diffuse from the lumen, into the epithelial cell, VIA facillitated diffusion.
step 4: This movement of na+ ions occurs in a co-transport protein , therefore it provides enough kinetic energy for the movement of glucose, or amino acids into the epithelial cells.
step 5: Glucose then moves by facillitated diffusion from the epithelial cells, into the blood.