A leaf out of nature

Turbo-charging photosynthesis in an "artificial leaf" could yield a vast commercial power source, say scientists.

Photosynthesis is the process by which plants convert solar energy into chemical energy. In the presence of visible light, carbon dioxide (CO2) and water (H20) are transformed into glucose and O2 during a complex series of chemical reactions. The glucose can be used as a fuel.

But the efficiency of photosynthesis is poor, as low as 5 percent.

When the enzyme that catalyzes steps in CO2 fixation, called Rubisco, becomes saturated, the process of producing carbohydrate slows down and that most absorbed light energy is lost as heat. When it’s sunny, a plant’s molecular machinery produces more electrons than the Rubisco carbohydrate-producing engine can handle, and a lot of those electrons are wasted.

Scientists want to harness the excess solar energy by transferring energy absorbed in a photosynthetic light harvesting cell via biological nanowires to a separate
cell that will produce fuel.

Given the low efficiency of photosynthesis, the top theoretical yield for squeezing energy out of the process with major crops such as wheat or sugar beets would be about five percent. But if efficiency could be forced up by even a few percentage points, they could be sitting on major biofuel production potential.

Efforts are on in various labs in the world. Can we prove one-up on nature?! Will the wonder-leaves we make churn out energy at the rate we guzzle, without affecting food production? With so less land arable, can we afford to turn over these lands to biofuels?