For the following scenarios, determine whether the molecules in the scenario are moving by (S) simple

Certainly! Here are the designations for each scenario based on the types of transport across cell membranes:

8. **(F)** For water to travel across the cell membrane at a substantial rate, the water molecules travel through protein channels known as aquaporins.
- **Explanation**: This is facilitated diffusion because it involves the use of protein channels to help diffuse water across the membrane.

9. **(S)** While water molecules are polar, they are also very small. One fact not mentioned in the video is that some water molecules are able to squeeze directly through the phospholipid bilayer due to their small size.
- **Explanation**: This is simple diffusion as water is moving directly through the membrane without the assistance of protein channels, though it is less common.

10. **(S)** Charged ions are traveling through a cell membrane with the concentration gradient.
- **Explanation**: This generally describes simple diffusion, although it's worth noting that charged ions typically require channels or carriers. If there are no specific channels noted, this scenario suggests passive movement (simple diffusion).

11. **(A)** Cells lining the gut need to take in glucose, but at a certain time, the concentration of extracellular glucose is lower than the concentration already stored in the cells.
- **Explanation**: This is active transport because glucose is moving against its concentration gradient, requiring energy (usually in the form of ATP).

12. **(F)** At a certain time, glucose is in a high concentration outside of a cell and needs to travel through the membrane into the cell.
- **Explanation**: This is facilitated diffusion since glucose typically requires a transport protein to move into the cell, even when moving down its concentration gradient.

In summary:

8. (F)
9. (S)
10. (S)
11. (A)
12. (F)