Plant cells do have mitochondria. Mitochondria are capsule-shaped organelles that float freely around the cells and provide it with energy. The energy comes from the nutrients the cell takes in and burns for fuel.
One of the products of this burning is a molecule called adenosine triphosphate, or ATP. ATP runs all the activities of the cell, including photosynthesis in a plant cell. When light strikes a molecule of chlorophyll in a chloroplast, it makes ATP and other chemicals. A chloroplast is another type of organelle in a plant cell.
The ATP produced by the mitochrondria helps the plant turn carbon dioxide from the air and water into sugars.