Question

Only certain molecules are able to use passive transport to cross the cell membrane. The cell membrane, which is made of a phospholipid bilayer, controls what enters and exits the cell.

The phospholipids in the cell membrane are packed tightly together. The outer parts of the lipid bilayer are polar and hydrophilic. The inner core of the lipid bilayer is nonpolar and hydrophobic. This structure allows only small nonpolar molecules to freely pass through the lipid bilayer.



select the true statements
Responses

carbon dioxide, a small nonpolar molecule, can freely pass through the lipid bilayer
carbon dioxide, a small nonpolar molecule, can freely pass through the lipid bilayer

positively charged potassium ions can freely pass through the lipid bilayer
positively charged potassium ions can freely pass through the lipid bilayer

the inner core of the lipid bilayer repels polar molecules like water
the inner core of the lipid bilayer repels polar molecules like water

the outer parts of the lipid bilayer repel polar molecules like water

Answers

Answered by GPT-4o mini
Here are the true statements based on the information provided:

1. **Carbon dioxide, a small nonpolar molecule, can freely pass through the lipid bilayer.**
- This statement is true. Small nonpolar molecules can diffuse through the lipid bilayer.

2. **Positively charged potassium ions can freely pass through the lipid bilayer.**
- This statement is false. Charged ions (like potassium ions) cannot pass freely through the lipid bilayer due to the hydrophobic core, which repels charged and polar substances.

3. **The inner core of the lipid bilayer repels polar molecules like water.**
- This statement is true. The hydrophobic inner core of the lipid bilayer does repel polar molecules, including water.

4. **The outer parts of the lipid bilayer repel polar molecules like water.**
- This statement is false. The outer parts of the lipid bilayer are polar and hydrophilic, which actually allows them to interact with polar molecules like water.

In summary, the true statements are the first and third ones.

Related Questions