Cell Membrane Transport

Flashcards covering diffusion, osmosis, passive and active transport.

Plasma membrane

The boundary that separates the living cell from its surroundings.

Plasma membrane

Exhibits selective permeability, allowing some substances to cross it more easily than others.

Phospholipids

The most abundant lipid in the plasma membrane.

Fluid mosaic model

States that a membrane is a fluid structure with a mosaic of various proteins embedded in it.

Diffusion

Movement of molecules from an area of high concentration to an area of low concentration.

Osmosis

Diffusion of water across a membrane.

Hypotonic Solution

One solution has a lower concentration of solute than another.

Hypertonic Solution

One solution has a higher concentration of solute than another.

Isotonic Solution

Both solutions have the same concentrations of solute.

Hypotonic

The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water)

Hypertonic

The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water)

Isotonic

The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.

Facilitated Diffusion

Does not require energy; Uses transport proteins to move high to low concentration.

Channel proteins

Are embedded in the cell membrane & have a pore for materials to cross.

Carrier proteins

Can change shape to move material from one side of the membrane to the other.

Active Transport

Requires energy or ATP; Moves materials from LOW to HIGH concentration; AGAINST concentration gradient.

Exocytosis

Moving things OUT; Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.