Overview of Photosynthesis
From the Greek: photo, “light”, and synthesis, “putting together”.
Definition of Photosynthesis
Photosynthesis is the process by which green plants, algae and some forms of bacteria use energy from sunlight to convert carbon dioxide and water into glucose.
General Equation for Oxygenic Photosynthesis
Let’s start with this equation and then you will see the simplified version in a minute.
The equation above shows….
carbon dioxide + water + light energy ——> glucose + oxygen + water
Let’s take a closer look at this equation…
Overall, six molecules of carbon dioxide (6CO2) and twelve molecules of water (12H2O) are consumed, while one molecule of glucose (C6H12O6), six molecules of oxygen (6O2) and six molecules of water (6H2O) are produced.
The equation above shows that water is both a reactant and a product of photosynthesis. Because twelve molecules of water are consumed and six molecules of water are produced, the equation can be simplified as shown below. This is the equation for photosynthesis that is most widely used.
This simplified balanced equation shows that six molecules of carbon dioxide (6CO2) are combined with six molecules of water (6H2O), using energy from sunlight, to produce one molecule of glucose (C6H12O6) and six molecules of oxygen (6O2).
- carbon dioxide
- sun’s energy
- Light dependent Reactions
- Calvin Cycle
Oxygenic vs. Anoxygenic Photosynthesis
Organisms capable of synthesizing their own food from inorganic substances, using sunlight as a source of energy are called Photoautotrophs. Most photosynthetic organisms or photoautotrophs, absorb carbon dioxide and produce oxygen. This is known as oxygenic photosynthesis. There are some species of bacteria, however, that perform anoxygenic photosynthesis. This means that they consume carbon dioxide but do not produce oxygen.