Integrated SequencePhysics Chemistry Organic Biology

Web Resources



  click if a link is broken



Special points of emphasis

Chemical Thermodynamics and the Equilibrium State

Chemical Kinetics

Proteins

The Michaelis-Menten equation expresses the relationship between the concentration of substrate and reaction rate. When the concentration is small, the rate is proportional to substrate concentration. When the concentration of substrate so large that it saturates the enzyme, the rate is maximal and no longer increases with greater substrate concentration. The equation rests on a model of enzyme activity where the rate is conceived as depending on the concentration of enzyme substrate complex, a concentration which is one side of the thermodynamic equilibrium between substrate and enzyme. The maximal rate (Vmax) occurs when the enzyme sites are saturated with substrate. Allosteric enzymes do not conform to the Micheaelis-Menten model because the binding of substrate to one active site can affect the properties of other active sites on the same enzyme molecule. Additionally, competitive inhibition does not change Vmax (the competitive inhibitor can be overcome by high substrate concentration), although with noncompetitive inhibition, Vmax does change.

While you definitely need to have a basic familiarity with Michaelis-Menten kinetics, very difficult enzyme kinetics questions would have a hard time finding their way onto the MCAT because it would produce too great an advantage for students who have taken biochemistry.




Heat and Temperature

Chemical Kinetics

Proteins

In model physical science systems, the rate of a chemical reaction typically doubles every 10oC increase in temperature. In biological systems, however, where biochemical reactions tend to be enzyme catalyzed, the dependence of rate on temperature is more complex. A particular enzyme will possess an optimal temperature. For example, ectotherms (i.e. 'cold blooded') can either occupy a habitat of constant temperature for optimal enzyme activity, such as the deep ocean, or their physiological processes may have adapted for a range of temperature. Temperature regulation in endothermic animals depends on the internal generation of heat to maintain a chemical environment for optimal enzyme function.







The WikiPremed MCAT Course is a free comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum.

Please read our policies on privacy and shipping & returns.  Contact Us.
MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course.


Creative Commons License
The work of WikiPremed is published under a Creative Commons Attribution Share Alike 3.0 License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions. You can use the resources here for commercial or non-commercial purposes, but please give attribution and a link to the production credits and edit history of the resource. For the works here which began as my individual work, please attribute "John Wetzel, an author at wikipremed.com".