ENZYMES are the hot topic this week!
From research and readings, I’ve decided that I’m going to discuss 2 properties of enzymes. These are Specificity and Substrate Concentration.
Enzymes only work on specific substrates. They are specific for the substrate and the reaction. They have a specific confirmation and they have an active site which consists of side groups of amino acid residues which are brought into close proximity in the tertiary structure. When the enzyme only can act on one substrate, it is said that the enzyme shows absolute specificity for the substrate. The interaction of the active site and substrate molecule involves:
1. electro static forces
2. Van-der-wall forces
3. hydrogen bonds
NB The substrate molecule MUST have a confirmation that fits closely into the active site.
Photo cred – http://www.rsc.org/Education/Teachers/Resources/cfb/images/07D.jpg
The rate of an enzyme controlled reaction increases with an an increase in substrate concentration up to a point. At low substrate concentrations, the active site of the enzymes are not all used up because there are not enough substrate molecules to occupy all the active sites. As substrate concentration increases, more and more active sites come into use until all are being used. Any further increase in substrate concentration cannot increase the rate of the reaction as the enzyme is the limiting factor. Therefore, the graph levels off.
This week was pretty good for me! One lesson I’ve learnt is that, God doesn’t give you anything you can’t handle. The work load might be a heavy burden but I CAN make it! Reflecting back on the past week all I can really say is that things are getting intense! Gotta keep at it! Si,se puede!
Other sources- http://biochemistryquestions.wordpress.com/2008/05/13/enzyme-specificity/