Untitled Flashcards Set

Facilitated diffusion: Movement of molecules across the cell membrane through protein channels, from high to low concentration, without energy.

Diffusion: Passive movement of particles from an area of high concentration to an area of low concentration.

Osmosis: Diffusion of water molecules across a selectively permeable membrane from a region of lower solute concentration to higher solute concentration.

Equilibrium: State where the concentration of molecules is equal throughout a space, with no net movement in any direction.

Selectively permeable membrane: A membrane that allows some substances to pass through while blocking others.

Hypotonic: A solution with a lower concentration of solutes compared to another solution, causing cells to swell as water enters.

Hypertonic: A solution with a higher concentration of solutes compared to another solution, causing cells to shrink as water exits.

Isotonic: A solution with an equal concentration of solutes as another solution, causing no net water movement into or out of cells.

Cholesterol: A lipid molecule within the cell membrane that helps maintain its fluidity and stability.

Phospholipid bilayer: The fundamental structure of the cell membrane, consisting of two layers of phospholipids with hydrophilic heads and hydrophobic tails.

Fatty Acid Tails: The hydrophobic (water-repelling) part of phospholipids that face inward in the bilayer.

Phosphate Heads: The hydrophilic (water-attracting) part of phospholipids that face outward towards water in the bilayer.

Peripheral Protein: Proteins attached to the exterior or interior surfaces of the cell membrane.

Vesicle: Small, membrane-bound sacs that transport substances within or outside the cell.

Integral protein: Proteins embedded within the cell membrane that can span the entire membrane.

Glycoprotein: Proteins with carbohydrate chains attached that play roles in cell recognition and signaling.

Glycolipid: Lipids with carbohydrate chains attached that are involved in cell recognition and membrane stability.

Passive Transport: Movement of substances across the cell membrane without the use of energy, down their concentration gradient.

Active transport: Movement of substances across the cell membrane using energy, often against their concentration gradient.

Exocytosis: The process by which cells expel materials in vesicles to the outside environment.

Endocytosis: The process by which cells take in materials by engulfing them in vesicles.