The story of leaves

Those of you who have followed InterestEng. from the beginning will remember our young Dr.Surprise, a boy from Ukraine who loved to surprise us with science stories about our solar system. Dr.Surprise is now grown and studying bio-engineering at the “Harvard of Ukraine” in Kiev. He recently wrote to say he missed writing for us.  He also mentioned that one of his science professors declared that the way to understand the most complicated things was to find a way to describe them to a child. Thus was born our new column “Ask Z-Guy”.  Andrei is part of the “Z generation”: those who have come to the end of the alphabet and want something entirely new.  Andrei is part of a generation who wants to give and be involved.  Welcome back, Andrei! 

Ask Z-Guy

Send your “how do . . . ?” questions for Z-Guy to:



How do leaves change color? The answer is easy!

AT one special season called autumn, fall leaves turn color. It creates a beautiful picture of nature preparing for winter. The process looks astonishing and it attracts people’s attention. 

There is nothing complicated or hard to understand about the process of how leaves change color. Leaves are full of a special and very important chemical called chlorophyll. It plays the main part in a huge chain of reactions that occur inside a leaf. Part of the reaction is creating sugar molecules and oxygen from CO2 (biggest component of air). All spring and summer, plants try to collect as much sugar deposits as they can. But also, you must know that leaves are full of many different, and not so useful, molecules.  These molecules all have different colors—most commonly red and yellow. These other pigments (or organic molecules) are not visible during the active period when leaves collect chlorophyll. There is so much chlorophyll produced by a plant that the other colored molecules are not visible to our eyes. But when autumn comes, the days become shorter and colder. It is a signal to the plant to stop its chlorophyll produc- tion because it’s not needed any more. As chlorophyll production is stopped other pigments begin to reveal their own colors, which appear as red, orange and yellow.  Leaves do not have any prac- tical purpose after their autumn transformation, and so soon after changing color they start to fall from the tree. All useful products are stored in a tree’s trunk for use during the hard period of life, the long, cold winter.  After winter all of this wonderful life cycle repeats itself again.

P.S.  Here is a fun video to help you understand as well.

 ©preInterestEng. July 2013  §  The stories in the magazine portion of the site are written by English language learners. Stories are corrected by a native English speaker.  § Photos are staff or used with permission.  §  To contact us: