Active transport: Difference between revisions
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Active transport is the movement of the molecules against their concentration gradient using [[ATP|Adenosine triphosphate (ATP)]] as a source of energy. There are two types of active transport; primary active transport and secondary active transport. Primary active transport is the movement of two different molecules using ATP. It is usually called ATPase; an example of this | Active transport is the movement of the molecules against their concentration gradient using [[ATP|Adenosine triphosphate (ATP)]] as a source of energy. There are two types of active transport; primary active transport and secondary active transport. Primary active transport is the movement of two different molecules using the energy released from the hydrolysis of ATP. It is usually called ATPase; an example of this of is [[Na+/K+ ATPase pump|Na<sup>+</sup>/K<sup>+</sup> ATPase]]. Secondary active transport is the co movement of one molecule by the other; the potential energy produced by the movement of molecule down its concentration gradient is used to drive the movement of another molecule against its concentration gradient. The two molecules can be transported in the same direction (symport) such as Na<sup>+ </sup>- glucose, or in different directions (antiport) such as Na<sup>+</sup> - Ca<sup>2+</sup> exchanger . An example of secondary active transport is [[Na+- Ca2+ exchanger|Na<sup>+</sup> - Ca<sup>2+</sup> exchanger]] for intracellular Ca<sup>2+ </sup>homeostasis<ref>Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P. (2008) Molecular biology of the cell, 5th edition, Garland science.</ref>. | ||
Active transport is very important as it allows the cell to uptake essential molecules such as [[Glucose|glucose]] even when they are at low concentrations outside the cell.<br> | Active transport is very important as it allows the cell to uptake essential molecules such as [[Glucose|glucose]] even when they are at low concentrations outside the cell.<br> | ||
Revision as of 22:08, 30 December 2010
Active transport is the movement of the molecules against their concentration gradient using Adenosine triphosphate (ATP) as a source of energy. There are two types of active transport; primary active transport and secondary active transport. Primary active transport is the movement of two different molecules using the energy released from the hydrolysis of ATP. It is usually called ATPase; an example of this of is Na+/K+ ATPase. Secondary active transport is the co movement of one molecule by the other; the potential energy produced by the movement of molecule down its concentration gradient is used to drive the movement of another molecule against its concentration gradient. The two molecules can be transported in the same direction (symport) such as Na+ - glucose, or in different directions (antiport) such as Na+ - Ca2+ exchanger . An example of secondary active transport is Na+ - Ca2+ exchanger for intracellular Ca2+ homeostasis[1].
Active transport is very important as it allows the cell to uptake essential molecules such as glucose even when they are at low concentrations outside the cell.
References:
- ↑ Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P. (2008) Molecular biology of the cell, 5th edition, Garland science.