Search results
Results From The WOW.Com Content Network
There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient. This process is in contrast to passive transport , which allows molecules or ions to move down their concentration gradient, from an area of high concentration to an area ...
Secondary active transport is when one solute moves down the electrochemical gradient to produce enough energy to force the transport of another solute from low concentration to high concentration. [ citation needed ] An example of where this occurs is in the movement of glucose within the proximal convoluted tubule (PCT).
This is in contrast to symporters, which are another type of cotransporter that moves two or more ions in the same direction, and primary active transport, which is directly powered by ATP. [2] Illustration of an antiporter and the concentration gradients of its transport substances [3] Transport may involve one or more of each type of solute.
As an active transport mechanism, exocytosis requires the use of energy to transport material. Exocytosis and its counterpart, endocytosis, are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. Exocytosis is the ...
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.
In bacterial efflux systems, certain substances that need to be extruded from the cell include surface components of the bacterial cell (e.g. capsular polysaccharides, lipopolysaccharides, and teichoic acid), proteins involved in bacterial pathogenesis (e.g. hemolysis, heme-binding protein, and alkaline protease), heme, hydrolytic enzymes, S ...
Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested materials. Endocytosis includes pinocytosis (cell drinking) and phagocytosis (cell eating). It is a form of ...
The P-type ATPases, also known as E 1-E 2 ATPases, are a large group of evolutionarily related ion and lipid pumps that are found in bacteria, archaea, and eukaryotes. [1] P-type ATPases are α-helical bundle primary transporters named based upon their ability to catalyze auto- (or self-) phosphorylation (hence P) of a key conserved aspartate residue within the pump and their energy source ...