Vascular
seedless plants, like all plants, use sunlight to provide their energy.
By carrying out photosynthesis, the plant is able to be self-sufficient,
storing energy harnessed from the sun by carbon fixation.The energy
captured in the photosynthetic process is used to produce a chemical
called adenosine triphosphate, or ATP, as well as NADPH, which are used
by the organism to assemble organic molecules such as sugars to use as
food.
The ATP molecule, shown below, works on the principle of
electromagnetic repulsion. To assemble an ATP molecule requires
the positioning of two negatively charged particles within a close
proximity, creating almost a
"spring tension" from the repulsion force, thus storing the energy for a
longer period in the form of chemical potential energy.
Photosynthesis, the process by which plants obtain energy, occurs in
two main steps; the dark and light reactions. In the light reactions,
sunlight, water, ADP, and NADP+ go in, and ATP, NADPH, and oxygen are
released. The NADPH and ATP are then used in the Calvin Cycle,
along with carbon dioxide gas, to produce organic molecules (food
molecules, i.e. sugars).1
