Cell Transport and Gradients

Flashcards covering key vocabulary terms related to cell transport, concentration gradients, and different types of diffusion and osmosis from the lecture notes.

Concentration Gradient

A difference in concentration between two solutions that are adjacent to each other, separated by a selectively permeable membrane.

Passive Transport

Movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached, requiring no ATP.

Equilibrium

A state where there is no difference in concentration between two adjacent solutions.

Active Transport

Movement of molecules from an area of low concentration to an area of high concentration (up the concentration gradient), requiring ATP.

Vesicular Transport

A special kind of transport that uses vesicles (cellular trucks) and requires ATP; it does not care about concentration gradients.

Diffusion

When molecules move from an area of high concentration to an area of low concentration until they reach an equilibrium.

Facilitated Diffusion

Molecules moving from an area of high concentration to an area of low concentration until equilibrium is reached, but they require the help of integral proteins (channels or carriers) to pass through the membrane.

Channel Mediated Diffusion

A type of facilitated diffusion where proteins (channels) open and close or stay open, allowing molecules to pass through the membrane.

Leaky Channels

Protein channels that remain open all the time, facilitating diffusion.

Gated Channels

Protein channels that can open and close, regulating the passage of molecules.

Carrier Mediated Diffusion

A type of facilitated diffusion where a protein specifically binds to a molecule and 'flips' it to the other side of the membrane, often one at a time.

Transport Maximum

The maximum rate at which molecules can be transported across a membrane, limited by the number of available channels or carrier proteins.

Osmosis

When water moves from an area of high concentration to an area of low concentration across a selectively permeable membrane until equilibrium is reached.

Hydrocephaly

A medical condition characterized by an accumulation of excess water in the brain.

Aquaporins

Protein channels that allow for bulk movement or bulk transport of water across a membrane (bulk osmosis).

Osmotic Pressure

Pressure exerted by water moving across a membrane due to a difference in water's concentration (related to solute concentration).

Hydrostatic Pressure

Pressure exerted by a fluid pushing against a wall (e.g., water pushing against a balloon).

Isotonic Solution

A solution where the concentration of solutes inside the cell is the same as the concentration of solutes outside the cell, resulting in equilibrium and no net movement of water.

Hypotonic Solution

A solution where there is a lower concentration of solutes outside the cell and a higher concentration inside the cell, causing water to move into the cell, which can lead to lysis.

Lysis

The bursting of a cell due to an excessive influx of water in a hypotonic solution.

Hypertonic Solution

A solution where there is a higher concentration of solutes outside the cell, causing water to move out of the cell, which can lead to shriveling of the cell.