Midnight, Texas â SERIES PREMIERE Based on Charlaine Harrisâ book series by the same name, âMidnight, Texasââ follows the lives of the inhabitants of a small town where the concept of normal is relative. A haven for vampires, witches, psychics, hit men and others with extraordinary backgrounds, Midnight gives outsiders a place to belong.
Facilitated diffusion. Definition. noun. Transport of substances across a biological membrane from an area of higher concentration to an area of lower concentration by means of a carrier molecule. Since the substances move along the direction of their concentration gradients, energy is not required.
Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins.olar molecules and large ions dissolved in water cannot diffuse freely across the plasma membrane due to the hydrophobic nature of the fatty acid tails of the phospholipids that make up the lipid bilayer. Only small, non-polar molecules, such as oxygen and carbon dioxide, can diffuse easily across the membrane.