/oss/taxonomy/term/708/all en /oss/article/nutrition-you-asked/why-does-lettuce-turn-brown <p>That’s an interesting question. How lettuce turns brown is well known. But why this happens is a different story. Let's deal with the how first. The chemistry that takes place when lettuce leaves become brown is the same chemistry we see when an apple is cut and turns brown, when green guacamole turns brown or when a green olive ripens and turns black. All these reactions occur when chemicals in the fruit or vegetable called polyphenols react with enzymes called polyphenoloxidases. Enzymes are specialized protein molecules made within cells and serve as catalysts.</p> Fri, 04 Jun 2021 20:24:53 +0000 Joe Schwarcz PhD 8755 at /oss /oss/article/did-you-know/trees-avoid-touching-each-other-due-crown-shyness-results-are-beautiful-webs-leaves <p>Trees might be tall and strong, but they are still a bit sheepish.</p> <p><u><a href="https://en.wikipedia.org/wiki/Crown_shyness">Crown shyness</a></u> describes the phenomenon of a tree’s leaves<a href="http://rstb.royalsocietypublishing.org/content/313/1159/209"> </a><u><a href="http://rstb.royalsocietypublishing.org/content/313/1159/209">withdrawing</a></u> from the leaves of other trees. It results in beautiful webs of <i>almost</i> touching canopies, but why do trees do it?</p> Wed, 19 Sep 2018 15:49:05 +0000 Ada McVean B.Sc. 7362 at /oss /oss/article/environment/why-do-leaves-have-autumn-colours <p>For many, the colour change of the leaves come September instigates a feeling of melancholy. Still, nobody denies that the reds, greens, oranges, and yellows are a spectacular sight! But what is behind this display that forebodes the long, bitter winter?</p> Wed, 07 Nov 2012 18:56:03 +0000 Amanda Scullion 1774 at /oss