Chloroplasts are the main cellular structure that is involved in plant photosynthesis. Chloroplasts contain large concentrations of chlorophyll, which is the primary pigment utilized in photosynthesis.
Chloroplasts are triple-membraned organelles that reside within plant cells. Their third membrane is known as the thylakoid membrane. It is in the thylakoid membranes that the chlorophyll resides. Chloroplasts are known as plastids due to their high concentrations of chlorophyll. These organelles are highly dynamic, and they have the ability to move freely within the plant cells. They can also pinch in two to reproduce. Chloroplasts contain their own DNA, which is why they can reproduce freely.
During photosynthesis, thylakoid membranes of the chloroplasts capture light energy from the Sun. The light energy reaches the chlorophyll pigments in the thylakoid membranes and energizes the electrons within the pigments. These electrons are then transported through an electron transport chain across the thylakoid membrane of the chloroplast. As the electrons move along the electron transport chain, they create energy in the form of ATP and NADPH. Each chlorophyll molecule in the chloroplasts replaces one of its lost electrons with an electron from water in the plant cells. This entire photosynthetic process releases oxygen into the atmosphere.