Study Guide on Cell Membranes and Cell Structure

Phospholipid Bilayer

Comprised of a hydrophilic head and two hydrophobic tails, crucial for forming the cell membrane.

Diffusion

Passive transport involving movement from high to low concentration.

Osmosis

Passive transport, diffusion of water across a semipermeable membrane.

Facilitated Diffusion

Passive transport through protein channels.

Active Transport

Requires energy to move substances against their concentration gradient.

Endocytosis

Process of engulfing substances into the cell.

Homeostasis

Maintaining internal environment by controlling what enters and exits the cell.

Selective Permeability

The cell membrane selectively allows substances to enter or exit based on their charge and size.

Exocytosis

Process of expelling substances from the cell.

Charged Molecules

Cannot easily pass through the membrane, e.g., sugars.

Uncharged Molecules

Can pass freely, e.g., oxygen and carbon dioxide.