Enzyme active site: Difference between revisions
Jump to navigation
Jump to search
Created page with ' The active site of an enzyme is the region on which the substrate is bound during catalysis. There can be either one or more substrate molecules and after binding to the en…' |
No edit summary |
||
| (One intermediate revision by one other user not shown) | |||
| Line 1: | Line 1: | ||
The active site of an [[Enzyme|enzyme]] is the region on which the[[Substrate|substrate]] (and any present [[Cofactor|cofactors]]) are bound during [[Catalysis|catalysis]]. There can be either one or more substrate [[Molecule|molecules]] and after binding to the enzyme the [[Enzyme-substrate complex|enzyme-substrate complex]] is formed. An enzyme's active site is the the location that directly lowers the change in Gibbs free energy of a reaction, producing faster rates of reaction as a result<ref>Berg J, Tymoczko J and Stryer L. (2006) Biochemistry, 6th Edition, New York, W.H. Freeman and Company</ref>. All reactions occur on the active site which is a 3D cleft or groove and the specificity of enzymes is due to the specific structural regions on the active site. The specificity can be explained by either of two binding methods:<br> | |||
#lock and key mechanism: whereby the substrate fits exactly on to the active site. | #lock and key mechanism: whereby the substrate fits exactly on to the active site due to its complementary shape. | ||
#induced fit mechanism: whereby upon binding the active site changes its shape so as to bind exactly with the substrate. | #induced fit mechanism: whereby upon binding the active site changes its shape so as to bind exactly with the substrate. | ||
At the end of catalysis, the enzyme and its active site remain unchanged and release the products. | At the end of catalysis, the enzyme and its active site remain unchanged and release the products. | ||
The active site of an enzyme can be altered by non-competitive inhibitors which changes the shape by binding elsewhere on the enzyme thus disabling its ability to bind with the substrate. | The active site of an enzyme can be altered by [[Non-competitive inhibitor|non-competitive inhibitors]] which changes the shape by binding elsewhere on the enzyme, thus disabling its ability to bind with the substrate <ref>Alberts, B., Johnson, A., Lewis, J., Kaff, M., Roberts, K. and Walter P. (2008) Molecular Biology of the Cell Fifth Edition. Abingdon: Garland Science.</ref> <ref>Alberts, B., Bray, D., Hopkin,K., Johnson, A., Lewis,J,Raff, M.,Roberts,K.,Walter,P.,(2004) Essential Cell Biology Second Edition.New York: Garland Science</ref>. | ||
=== References === | |||
<references /> | |||
<br> | |||
<br> | |||
Latest revision as of 22:14, 16 November 2013
The active site of an enzyme is the region on which thesubstrate (and any present cofactors) are bound during catalysis. There can be either one or more substrate molecules and after binding to the enzyme the enzyme-substrate complex is formed. An enzyme's active site is the the location that directly lowers the change in Gibbs free energy of a reaction, producing faster rates of reaction as a result[1]. All reactions occur on the active site which is a 3D cleft or groove and the specificity of enzymes is due to the specific structural regions on the active site. The specificity can be explained by either of two binding methods:
- lock and key mechanism: whereby the substrate fits exactly on to the active site due to its complementary shape.
- induced fit mechanism: whereby upon binding the active site changes its shape so as to bind exactly with the substrate.
At the end of catalysis, the enzyme and its active site remain unchanged and release the products.
The active site of an enzyme can be altered by non-competitive inhibitors which changes the shape by binding elsewhere on the enzyme, thus disabling its ability to bind with the substrate [2] [3].
References
- ↑ Berg J, Tymoczko J and Stryer L. (2006) Biochemistry, 6th Edition, New York, W.H. Freeman and Company
- ↑ Alberts, B., Johnson, A., Lewis, J., Kaff, M., Roberts, K. and Walter P. (2008) Molecular Biology of the Cell Fifth Edition. Abingdon: Garland Science.
- ↑ Alberts, B., Bray, D., Hopkin,K., Johnson, A., Lewis,J,Raff, M.,Roberts,K.,Walter,P.,(2004) Essential Cell Biology Second Edition.New York: Garland Science