Final answer:
Lipid-soluble molecules and small polar molecules that are rapidly absorbed can pass through cell membranes through different mechanisms. Lipid-soluble molecules can slip through the hydrophobic lipid core of the plasma membrane, while small polar molecules can enter absorptive cells directly through simple diffusion.
Step-by-step explanation:
Lipid-soluble molecules and small polar molecules that are rapidly absorbed are able to pass through cell membranes through different mechanisms. Lipid-soluble molecules and small polar molecules that are rapidly absorbed can pass through cell membranes through different mechanisms. Lipid-soluble molecules can slip through the hydrophobic lipid core of the plasma membrane, while small polar molecules can enter absorptive cells directly through simple diffusion.
Lipid-soluble molecules, such as fat-soluble vitamins and fat-soluble drugs, can easily slip through the hydrophobic lipid core of the plasma membrane. These molecules can pass through the plasma membranes in the digestive tract and other tissues. On the other hand, small polar molecules that are rapidly absorbed, such as short-chain fatty acids, can enter the absorptive cells directly through simple diffusion.