It means that in order to cross a barrier, for example a cell membrane, a substance must have a facilitator substance to make it permeable to the barrier.
For instance, glucose cannot enter cells unless insulin is present to facilitate the diffusion of glucose from blood to cell. Without the insulin, or with damaged insulin receptors on the cell membrane, the cell membrane remains impermeable to glucose and it cannot enter the cells, so it remains in the blood plasma. This is what causes Diabetes.
Bacteria can enter a cell through a process called phagocytosis, where the cell engulfs the bacteria using its cell membrane. Alternatively, some bacteria can invade cells by injecting proteins that manipulate the host cell machinery to gain entry.
Neither of these require energy. Diffusion occurs naturally when a higher concentration of a substance exists on one side of a membrane than the other; molecules will enter into the area of lesser concentration until there is an equilibrium on both sides. Active transport requires the energy of the cell.
Facilitated diffusion needs some sort of help. Often it would be a protein. Simple diffusion doesn't. If you spill something smelly on the floor in the kitchen, you will smell it all through the house. It will spread by simple diffusion.
The process that permits absorption of glucose into cells is called facilitated diffusion. Glucose is transported across cell membranes with the help of glucose transport proteins, such as GLUT-1 and GLUT-4. These proteins allow glucose to move down its concentration gradient and into the cells where it can be used for energy production.
Facilitated diffusion is a type of passive transport in cells where specific molecules are moved across the cell membrane with the help of protein channels or carriers. These proteins assist in the movement of molecules that cannot easily pass through the lipid bilayer on their own.
Bacteria can enter a cell through a process called phagocytosis, where the cell engulfs the bacteria using its cell membrane. Alternatively, some bacteria can invade cells by injecting proteins that manipulate the host cell machinery to gain entry.
Facilitated and simple diffusion both transport solutes along a concentration gradient and neither processes require any ATP expenditure.
Facilitated diffusion does not require energy because it relies on the use of carrier proteins to transport molecules across a cell membrane down their concentration gradient. These carrier proteins facilitate the movement of specific molecules such as glucose or ions without the need for ATP or energy input.
in the normal diffusion the substance move from the area of greater concentration to that of lower concentration. .... but i never know what do we mean be "faciliated" plz specify
Neither of these require energy. Diffusion occurs naturally when a higher concentration of a substance exists on one side of a membrane than the other; molecules will enter into the area of lesser concentration until there is an equilibrium on both sides. Active transport requires the energy of the cell.
Facilitated diffusion needs some sort of help. Often it would be a protein. Simple diffusion doesn't. If you spill something smelly on the floor in the kitchen, you will smell it all through the house. It will spread by simple diffusion.
Vitamin C is water soluable so the only way it can be transported is by faciliated difficusion using a channel protein. Channel proteins allow polar, watersoluable substances and ions to pass across the cell membrane using faciliated diffusion. Vitamin D is lipid soluble therefore it can pass through using simple diffusion because the phospholipid bilayer lets it pass through down its concentration gradient.
The process that permits absorption of glucose into cells is called facilitated diffusion. Glucose is transported across cell membranes with the help of glucose transport proteins, such as GLUT-1 and GLUT-4. These proteins allow glucose to move down its concentration gradient and into the cells where it can be used for energy production.
Apparent diffusion coefficient (ADC) is a measure of water diffusion in all directions, while mean diffusivity is a measure of the average diffusion within a voxel. ADC includes the effects of both isotropic and anisotropic diffusion, whereas mean diffusivity reflects the overall diffusion within the voxel. In DTI, ADC is calculated as the average of the three eigenvalues, which correspond to the three principal diffusion directions and contribute to mean diffusivity.
what do you mean
Simple and facilitated diffusion are a part of passive transport. This refers to the movement of molecules, atoms and ions across the cell membrane. In both of these processes, molecules move from areas of high concentration to areas of lower concentration because equilibrium is trying to be maintained in living organisms. Simple diffusion just happens randomly and without any aides. Facilitated diffusion uses proteins in the cell membrane to guide polar molecules and ions in and out of the membrane (always to areas of lower concentration) and DOES NOT require ENERGY.Only active diffusion requires energy.
fatty acids membranes