Jerry Crimson Mann is author, released under GNU license. Modified to PNG format.
<a href="https://en.wikipedia.org/wiki/User:TimVickers" class="extiw" title="en:User:TimVickers">TimVickers</a>
<a href="https://en.wikipedia.org/wiki/Image:Competitive_inhibition.png" class="extiw" title="en:Image:Competitive inhibition.png">en:Image:Competitive_inhibition.png</a>