Final answer:
The movement of large, polar/charged particles across lipid bilayers occurs through Facilitated Diffusion, which involves specific proteins helping such molecules to move down their concentration gradients.
Step-by-step explanation:
The movement of large, polar/charged particles across lipid bilayers is most accurately described as Facilitated Diffusion. This process occurs because large polar molecules and charged particles cannot easily cross the phospholipid bilayer without assistance due to their size, charge, and polarity. Instead, these substances rely on specific membrane proteins, such as carriers or channels, that allow them to diffuse down their concentration gradients without the need for cellular energy. An example of facilitated diffusion is the movement of glucose into the cell through a glucose transporter, enabling it to contribute to ATP production within the cell.