Recording-2025-03-03T19:03:50

phospholipid

A molecule that forms the bilayer of cell membranes, consisting of a polar head and two nonpolar tails.

fluid mosaic model

The current accepted model of cell membranes, depicting them as a flexible structure with various proteins embedded in or associated with the phospholipid bilayer.

selective permeability

The property of cell membranes that allows certain molecules to pass through while blocking others.

Brownian motion

The random movement of particles in a fluid due to collisions with fast-moving molecules.

diffusion

The process by which particles spread out from an area of higher concentration to an area of lower concentration.

passive transport

The movement of molecules across a membrane without the use of energy, typically down their concentration gradient.

osmosis

The diffusion of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

isotonic solution

A solution in which the concentration of solutes is equal on both sides of a membrane, resulting in no net movement of water.

hypertonic solution

A solution with a higher concentration of solutes compared to another solution, causing water to move out of cells.

hypotonic solution

A solution with a lower concentration of solutes compared to another solution, leading to water moving into cells.

active transport

The process of moving molecules across a membrane against their concentration gradient, requiring energy.

facilitated diffusion

A type of passive transport where molecules move across a membrane through protein channels.

concentration gradient

A difference in the concentration of a substance across a space, which drives diffusion.

aldosterone

A hormone produced by the adrenal glands that helps regulate water and sodium balance in the body.

antidiuretic hormone (ADH)

A hormone that helps control blood pressure and water balance by promoting water reabsorption in the kidneys.

atrial natriuretic peptide (ANP)

A hormone released by the heart that promotes the loss of sodium and water to decrease blood volume.

sodium-potassium pump

A membrane protein that uses ATP to actively transport sodium out of and potassium into cells.

osmotic balance

The maintenance of proper concentrations of solutes and water in bodily fluids, crucial for cell function.

kidneys

Organs that filter blood, remove waste, and regulate water and electrolyte balance in the body.

electrolyte imbalance

An abnormal concentration of electrolytes in the body, which can lead to serious health issues.