HOW LEAVES WORK
Editor’s Note: This article by Nathan F. (’16) was inspired by an interesting Science Times article he read, and uses simple language to describe to complex process of how plants work.
Pollution caused by using wasteful energy sources is now one of the world’s greatest issues. It affects not only those who burn the gas, but also those who can’t even afford it. It has been predicted that the world will be a completely different place in just a couple years. We are desperately trying to find solutions for our pollution before it’s too late. In this search to find a better source of energy many scientists look at plants; the all in one energy producer and consumer. Jack Hitt’s New York Times article, “The Artificial Leaf is Here. Again,” discusses what seems to be the intersection between the perfection of science and the simplicity of nature. Jack Hitt says a man-made leaf may be just around the corner. We are told that this technology will be capable of turning a house into its own power station; where energy is produced, stored, and used. This great concept could help solve our environmental issue, but any new fuel production systems must be studied deeply before it is adapted. Before we harness energy with an artificial leaf, we should probably answer the question, what does a natural leaf have to do with energy?
Plants, and their leaves especially, are all energy. By that I mean every part of the plant, excluding the reproductive parts, is dedicated to producing usable energy. A plant’s usable energy is glucose. The plant produces this energy via a process called photosynthesis. A plant needs three things (along with a few minerals) to complete photosynthesis: water, carbon dioxide, and sunlight. When light shines down on a leaf it is striking the chloroplast cells. Inside the chloroplast there is a compound called chlorophyll. The chlorophyll is what sparks the entire glucose producing process. Most people are familiar with chlorophyll and its famous earthy green color, but most don’t know how the molecule performs its job. The chlorophyll is capable of starting the production of glucose because it absorbs light energy from the sun.Light, something found anywhere you can see, is a type of energy. Light travels in different length waves, and only some lengths are visible to humans. The length of a wave corresponds to the color we perceive that wave to be. When we see an object’s color, we are really seeing the waves that are being reflected by the object; all other waves are being absorbed. Chlorophyll is known for its green color because that is the only (visible) wave it doesn’t absorb. The other waves are absorbed and used to convert carbon dioxide and water into energy the plant can use to grow.
While the chlorophyll was converting the light energy into chemical energy, the roots and chloroplasts were absorbing ample water and carbon dioxide. The chemical energy is used to bond the carbon dioxide and water in a way such that glucose is formed. The chemical formula for this reaction is 6CO2+ 6H2O ==> C6H12O6 + 6O2. The plant consumes and grows from the glucose. The byproduct, oxygen, is emitted into the atmosphere. In the case of the artificial leaf, we would have hydrogen as the emitted byproduct. Hydrogen is one the clean fuels we are looking for. Plants are known for their high yield of energy and we would try to match this in our man made edition.
A man made leaf is terrific idea if it accomplishes what a plant does. There are limitations with an artificial leaf that aren’t accounted for in the traditional leaf. Plants are built to use the glucose they produce, but most manmade appliances aren’t built to use hydrogen fuel. Many appliances run on electricity. Hydrogen can be converted into electricity, but this process requires a fuel cell. The addition of a fuel cell increases the cost of the already expensive artificial leaf. It would be hard to sell these two things to all the energy consumers in the world. Its not only high cost that would make selling leaves difficult, but convincing people who deny global warming to spend money green energy may be futile. Teaching the deniers how a leaf functions may lend itself to convincing those same people that green energy is worth it. Although the artificial leaf may be a few years away, it is important people start understanding the concept of green energy immediately.
Plants, and their leaves especially, are all energy. By that I mean every part of the plant, excluding the reproductive parts, is dedicated to producing usable energy. A plant’s usable energy is glucose. The plant produces this energy via a process called photosynthesis. A plant needs three things (along with a few minerals) to complete photosynthesis: water, carbon dioxide, and sunlight. When light shines down on a leaf it is striking the chloroplast cells. Inside the chloroplast there is a compound called chlorophyll. The chlorophyll is what sparks the entire glucose producing process. Most people are familiar with chlorophyll and its famous earthy green color, but most don’t know how the molecule performs its job. The chlorophyll is capable of starting the production of glucose because it absorbs light energy from the sun.Light, something found anywhere you can see, is a type of energy. Light travels in different length waves, and only some lengths are visible to humans. The length of a wave corresponds to the color we perceive that wave to be. When we see an object’s color, we are really seeing the waves that are being reflected by the object; all other waves are being absorbed. Chlorophyll is known for its green color because that is the only (visible) wave it doesn’t absorb. The other waves are absorbed and used to convert carbon dioxide and water into energy the plant can use to grow.
While the chlorophyll was converting the light energy into chemical energy, the roots and chloroplasts were absorbing ample water and carbon dioxide. The chemical energy is used to bond the carbon dioxide and water in a way such that glucose is formed. The chemical formula for this reaction is 6CO2+ 6H2O ==> C6H12O6 + 6O2. The plant consumes and grows from the glucose. The byproduct, oxygen, is emitted into the atmosphere. In the case of the artificial leaf, we would have hydrogen as the emitted byproduct. Hydrogen is one the clean fuels we are looking for. Plants are known for their high yield of energy and we would try to match this in our man made edition.
A man made leaf is terrific idea if it accomplishes what a plant does. There are limitations with an artificial leaf that aren’t accounted for in the traditional leaf. Plants are built to use the glucose they produce, but most manmade appliances aren’t built to use hydrogen fuel. Many appliances run on electricity. Hydrogen can be converted into electricity, but this process requires a fuel cell. The addition of a fuel cell increases the cost of the already expensive artificial leaf. It would be hard to sell these two things to all the energy consumers in the world. Its not only high cost that would make selling leaves difficult, but convincing people who deny global warming to spend money green energy may be futile. Teaching the deniers how a leaf functions may lend itself to convincing those same people that green energy is worth it. Although the artificial leaf may be a few years away, it is important people start understanding the concept of green energy immediately.
References
Harris, W. (2000, July 10). How Light Works. Retrieved from http://www.howstuffworks.com/light1.htm
Hitt, J. (2014, March 29). The Artificial Leaf Is Here. Again. Retrieved from http://www.nytimes.com/2014/03/30/technology/the-artificial-leaf-is-here-again.html
Photosynthesis. (2006, April 14). Retrieved from http://biologymadesimple.com/topics/plant-physiology/photosynthesis/
Photosynthesis Made Easy. (2013, January 03). Retrieved from http://www.youtube.com/watch?v=wHMNovYseps
Harris, W. (2000, July 10). How Light Works. Retrieved from http://www.howstuffworks.com/light1.htm
Hitt, J. (2014, March 29). The Artificial Leaf Is Here. Again. Retrieved from http://www.nytimes.com/2014/03/30/technology/the-artificial-leaf-is-here-again.html
Photosynthesis. (2006, April 14). Retrieved from http://biologymadesimple.com/topics/plant-physiology/photosynthesis/
Photosynthesis Made Easy. (2013, January 03). Retrieved from http://www.youtube.com/watch?v=wHMNovYseps
