Search results
Results from the WOW.Com Content Network
Ground substance provides lubrication for collagen fibers. [2] The components of the ground substance vary depending on the tissue. Ground substance is primarily composed of water and large organic molecules, such as glycosaminoglycans (GAGs), proteoglycans, and glycoproteins. GAGs are polysaccharides that trap water, giving the ground ...
[citation needed] Primary active transport uses adenosine triphosphate (ATP) to move specific molecules and solutes against its concentration gradient. Examples of molecules that follow this process are potassium K +, sodium Na +, and calcium Ca 2+. A place in the human body where this occurs is in the intestines with the uptake of glucose.
Both molecules are transported in the same direction. An example is the glucose symporter SGLT1, which co-transports one glucose (or galactose) molecule into the cell for every two sodium ions it imports into the cell. [27] This symporter is located in the small intestines, [28] heart, [29] and brain. [30]
By understanding the method in which substances move along neurons or microtubules it is possible to target specific pathways for disease. Currently, many drug companies are aiming to utilize the trajectory of intracellular transport mechanisms to deliver drugs to localized regions and target cells without harming healthy neighboring cells.
The classic view of water in cells is that about 5% of this water is strongly bound in by solutes or macromolecules as water of solvation, while the majority has the same structure as pure water. [5] This water of solvation is not active in osmosis and may have different solvent properties, so that some dissolved molecules are excluded, while ...
Tight junctions are multi-protein complexes that hold cells of a same tissue together and prevent movement of water and water-soluble molecules between cells. In epithelial cells, they function also to separate the extracellular fluid surrounding their apical and basolateral membranes. [ 1 ]
This tissue system is present between the dermal tissue and forms the main bulk of the plant body. Parenchyma cells have thin primary walls and usually remain alive after they become mature. Parenchyma forms the "filler" tissue in the soft parts of plants, and is usually present in cortex , pericycle , pith , and medullary rays in primary stem ...
Thermodynamically the flow of substances from one compartment to another can occur in the direction of a concentration or electrochemical gradient or against it. If the exchange of substances occurs in the direction of the gradient, that is, in the direction of decreasing potential, there is no requirement for an input of energy from outside the system; if, however, the transport is against ...