Plant cells are cells that are in plants. Plant cells are like animal cells, but they have a cell wall and chloroplasts.A very special process that takes place inside of the chloroplasts in plant cells is called photosynthesis. Photo means "light" and synthesis means " putting things together." In photosynthesis, green plants actually make their own food. In photosynthesis, the chloropyll takes in energy from sunlight. The energy comes in the form of a tiny bundle known as a photon. The photon hits a molecule of water inside the chlorophyll. The photon's energy splits the water molecule into hydrogen and oxygen. The hydrogen combines with carbon dioxide (which the plant has absorbed from the air) to make sugars or glucose. The oxygen is released back into the atmosphere to give us more air.
Did you know that the largest suppliers of oxygen in the whole world are tiny plants known as photoplankton? They are found in the oceans and are really important to giving us the oxygen needed to keep life going on our planet.
Believe it or not, a plant uses only about one-sixth of the energy it gets from the sun to nourish itself. The rest of the energy is stored in the glucose until it is eaten by other animals or humans.