Cell Transport and Membrane Dynamics

Vocabulary flashcards covering cellular transport mechanisms, passive and active transport, membrane proteins, and solution tonicity based on lecture notes.

Diffusion

The movement of particles from an area of high concentration to low concentration that occurs naturally in liquids and gases (e.g., perfume smell spreading through a room).

Endocytosis

A process where the cell uses its membrane to bring large material INTO the cell by surrounding and taking in a large particle.

Passive Transport

Movement across the cell membrane that DOES NOT require energy (ATP), such as diffusion, osmosis, and facilitated diffusion.

Exocytosis

A process where the cell uses a vesicle to send materials out of the cell, such as releasing proteins or hormones outside the cell.

Osmosis

The diffusion of WATER across a selectively permeable membrane from high water concentration to low concentration.

Carrier Protein

A membrane protein that binds to a specific substance and changes shape to move it across the cell membrane (e.g., helping glucose move into a cell).

Hypertonic Solution

A solution outside the cell that has more solute/less water than inside the cell, resulting in water moving OUT of the cell so the cell shrinks.

Hypotonic Solution

A solution outside the cell that has less solute/more water than inside the cell, resulting in water moving INTO the cell so the cell swells.

Isotonic Solution

A solution outside the cell that has about the same concentration of solutes as inside the cell, resulting in water moving in and out at about the same rate so the cell stays about the same size.

Pinocytosis

A type of endocytosis where the cell takes in LIQUIDS/Fluid from its surroundings.

Phagocytosis

A type of endocytosis where the cell engulfs large particles or cells (solid material), such as a white blood cell surrounding a harmful particle.

Active Transport

Movement of substances across the cell membrane that REQUIRES ENERGY (ATP) to move particles from low to high concentration.

Red Blood Cell Isotonicity

Red blood cells are isotonic to a $0.9\%$ salt solution.

Protein Pump

A membrane protein that uses ATP energy to move substances across the membrane, such as the sodium-potassium pump moving sodium and potassium ions.

Channel Protein

A membrane protein that forms a passageway (acting like a doorway) for certain particles, such as ions, to cross the cell membrane.

Facilitated Diffusion

Movement of particles from high to low concentration through a protein in the cell membrane without requiring energy (e.g., glucose moving through a membrane protein).