How leaves obserbe light

Question

how leaves obserbe light

Answer 1

Plants have pigment molecules arranged in their chloroplasts.  Pigment molecules, like chlorophyll, have a reactive center.  For example, chlorophyll generally has a magnesium atom in its center.  When the light waves (which are energy) strike the magnesium atom, it causes an electron in its outer shell to become excited.  That electron will then jump to another chlorophyll molecule, displacing its electron, etc.  

There are a whole bunch of chlorophyll molecules clumped together and the electrons will bounce around them until it reaches a special chlorophyll called the reaction center.  The reaction center then passes the electron to an electron acceptor which shuttles the electron through a chain of different intermediate molecules, each one with a lower energy.  The energy that is lost with each transfer is used to move hydrogen ions across a membrane.  This sets up a concentration gradient which is a way to store energy before using it to make ATP.

Answer 2

They obserbe light through polyinclumation, in which the waves of light cause microscopic waves of water in the leaves to begin vibrating, producing energy for the plant.