Photosynthesis and Ecology

Trevor Craig

Energy Science 110

Photosynthesis and Ecology, 9

9/22/11           

This lecture was about how photosynthesis works and how this affects crop production. Light reflects off of certain objects and is absorbed by others. Light is reflected by white objects and absorbed by black objects increasing their temperature, and green for the color of plants, takes in some light and also reflects some light back. The pigment in plants is called chlorophyll, it takes in blue light which is 450nm and red light, 700nm, and then reflects green light 525nm, hence the green color we see; this absorption of light leads the plant on the phases of photosynthesis.

Photosynthesis can be explained by this equation 6(H2O)+ 6(CO2) àC6H12O6+6(O2), so in words water and carbon dioxide, when reacted with solar energy reacts and creates oxygen and sugar, which the plant will use to grow and continue photosynthesis. What happens in the equation for photosynthesis is that water is split, and that makes the rest of the equation possible. Plants are pretty good at photosynthesis but they do not use all of the suns energy in photosynthesis, only about 5% of the total energy is converted into carbohydrates.

Photosynthesis would not be possible without oxidation and reduction reactions. Oxidation is when there is a removal of an electron, and reduction is when an electron is added to a molecule or atom. Plants have a problem sometimes when it comes to evaporation of water from the pores; plants in order to stay as they are need to take in CO2, which is about .003% of the atmosphere and not lose any water. About 400 molecules of H20 are lost for every CO2 molecule absorbed; obviously water is vital for a plant.

There are 3 different categories of photosynthesis, some are more effective than others, the 3 types are C3 Photosynthesis, which is the most common, C4 Photosynthesis which is much more efficient than C3, and CAM Photosynthesis, which is a little like C4 but also differs a little. Although some forms are more effective than others they all can only take in so much solar radiation, when plants reach a little more than 600 Wm-2 of irradiance they no longer go up in crop photosynthesis, in other words it is no longer beneficial for the plant.

There are ways to increase the efficiency of plants, for example providing more water for plants, or providing more CO2 for plants, because in a study when plants were in an environment with more CO2 than normal wheat increased in water use efficiency by 24.4%. There are other ways that can help increase efficiency in plants photosynthesis we just need to discover these techniques.

Polymerization- The bonding of two or more monomers to form a polymer, or a chemical process that effects this bonding.

Saturation- the act or process of saturating.

ENSC110 Craig Photosynthesis and Ecology 9