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The action of the sodium-potassium pump is an example of primary active transport. Primary active transport, also called direct active transport, directly uses metabolic energy to transport molecules across a membrane. [12] Substances that are transported across the cell membrane by primary active transport include metal ions, such as Na +, K ...
Active transport is the process of moving molecules from an area of low concentrations to an area of high concentration. There are two types of active transport, primary active transport and secondary active transport .
A comparison of transport proteins [1]. An antiporter (also called exchanger or counter-transporter) is an integral membrane protein that uses secondary active transport to move two or more molecules in opposite directions across a phospholipid membrane.
Active transport is the movement of a substance across a membrane against its concentration gradient. This is usually to accumulate high concentrations of molecules that a cell needs, such as glucose or amino acids. If the process uses chemical energy, such as adenosine triphosphate (ATP), it is called primary active transport.
Hence reabsorption of glucose is dependent upon the existing sodium gradient which is generated through the active functioning of the Na + /K +-ATPase. As the cotransport of glucose with sodium from the lumen does not directly require ATP hydrolysis but depends upon the action of the ATPase, this is described as secondary active transport. [10]
Cotransporters are a subcategory of membrane transport proteins (transporters) that couple the favorable movement of one molecule with its concentration gradient and unfavorable movement of another molecule against its concentration gradient. They enable coupled or cotransport (secondary active transport) and include antiporters and symporters.
Exocytosis (/ ˌ ɛ k s oʊ s aɪ ˈ t oʊ s ɪ s / [1] [2]) is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell (exo-+ cytosis). As an active transport mechanism, exocytosis requires the use of energy to transport material.
Comparison of transport proteins A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of ...