The Green Factory

A leaf is like a solar panel. The pigments in the leaf absorb solar radiation:

• the green chlorophyl absorbs blue and red
• other pigments absorb blue/violet light. In the fall, these other pigments become visible and the leaves appear as yellow, brown and red. See maple leaf.

The components within the plant cells that perform photosynthesis are known as chloroplasts. It is now widely believed that chloroplasts were originally independent cyanobacteria or blue-green bacteria which were absorbed by other cells in a symbiotic relationship. Many of the features of the original bacteria, no longer required, would have disappeared over time.

Animals eat plants and convert the carbohydrates back to energy. Plants also convert carbohydrates back to energy. Carbohydrates are also used to produce byproducts such as chlorophyl, fats, oils and proteins. Oxygen is used as a catalyst; minerals from the soil are also used. Nitrogen plays an important part in constructing more complex organic compounds.

It is also widely believed that the mitochondria used to produce energy in the cells of plants and animals are descended from purple bacteria. Mitochondria enable the cells to use oxygen in energy production.

Predators become dependent on their prey. They are also usually less abundant. When a food item becomes less abundant, any species that consumes that food item either finds other sources of food or will eventually experience a decline in its own population.

Related Links

• Photosynthesis - Botany Online
• Mitochondria
• Genomics and chloroplast evolution: what did cyanobacteria do for plants?
• Origin of Mitochondria in Eukaryotic Cells
• the carbon cycle