View source for Krebs cycle step 7

<h2>Step 7 of the Krebs cycle: [[Fumarase]]</h2>

[[Image:fumarase_2.jpg]]
<p>Figure: Formation of L-Malate</p>

<p>L-malate is formed out of fumarate by adding water to the double bond; therefore, the reaction type is a hydration.  The reaction process is unusual becaue the first step is the addition of  OH<sup>-</sup>. As a result, a negativley charged carbanion is formed. The addition of the proton  on the opposite side of the hydroxy group, leads to the formation 
of L-malate. The catalysing enzyme fumarase is highly stereospecific, which can be seen from the fact that only L-malate is formed as a product and not a mixture of  D-malate and L-malate.</p>