Question

select the true statements. carbon dioxide, a small nonpolar molecule, 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.

Explanation:

To determine the true statements, we analyze each option based on the structure and properties of the lipid bilayer (composed of phospholipids with polar heads and nonpolar tails):

1. Carbon dioxide, a small nonpolar molecule, can freely pass through the lipid bilayer.

The lipid bilayer’s inner core is nonpolar (due to the nonpolar tails of phospholipids). Nonpolar molecules (like CO₂) can dissolve in and pass through nonpolar regions. So this statement is true.

2. Positively charged potassium ions can freely pass through the lipid bilayer.

Ions (like K⁺) are charged (polar) and cannot pass through the nonpolar inner core of the lipid bilayer freely. They require transport proteins (e.g., ion channels) to cross. So this statement is false.

3. The inner core of the lipid bilayer repels polar molecules like water.

The inner core of the lipid bilayer is nonpolar (hydrophobic). Polar molecules (like water) are hydrophilic and are repelled by the nonpolar, hydrophobic core. So this statement is true.

Answer:

• Carbon dioxide, a small nonpolar molecule, can freely pass through the lipid bilayer.
• The inner core of the lipid bilayer repels polar molecules like water.

(Note: The statement about potassium ions is false and should not be selected.)