Movement Thru Membrane

These flashcards cover key concepts related to membrane transport, including differences between passive and active transport processes, the role of osmosis, tonicity, and methods of cellular uptake and release.

Passive Transport

The movement of substances across a membrane without the use of energy, occurring along a concentration gradient from high to low concentration.

Active Transport

The movement of substances against a concentration gradient, requiring energy (ATP) and protein carriers to transport molecules from low to high concentration.

Diffusion

The net movement of a substance from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Concentration Gradient

The difference in the concentration of a substance between two areas.

Facilitated Diffusion

A type of passive transport where substances move along the concentration gradient with the help of a carrier protein.

Tonicity

The relative concentration of solutes in a solution that will determine the direction and extent of diffusion, classified as hypotonic, hypertonic, or isotonic.

Isotonic Solution

A solution that does not cause osmotic flow; the concentration of solutes is the same inside and outside the cell.

Hypotonic Solution

A solution with a lower solute concentration than the cell, causing the cell to gain water and potentially rupture.

Hypertonic Solution

A solution with a higher solute concentration than the cell, causing the cell to lose water and potentially shrink.

Phagocytosis

A type of endocytosis where the cell engulfs large particles or microorganisms by surrounding them with its membrane.

Pinocytosis

A type of endocytosis known as 'cell drinking,' where the cell takes in fluid from the extracellular environment.

Exocytosis

The process in which a vesicle inside the cell fuses with the plasma membrane to release its contents into the extracellular fluid.

Osmotic Pressure

The pressure required to prevent osmosis across a semipermeable membrane, opposing the movement of water.

Hydrostatic Pressure

The force exerted by a fluid against the walls of its container, contributing to the movement of water and solutes.

Carrier Proteins

Proteins that transport molecules across a membrane, playing a crucial role in both facilitated diffusion and active transport.