Photosynthesis is a chemical process that plants and other photosynthetic organisms fix carbon dioxide and water into glucose and release oxygen by using energy of sunlight. Glucose is a kind of sugar and it can be converted into starch, fat, proteins and other components of cells. Photosynthesis can be simply expressed in the equation listed below.
Photosynthesis is considered to be the most important chemical reaction on the earth.
This is because, firstly, oxygen in air originated from photosynthesis. Based on scientific studies, during the early days of the earth, there was no free oxygen in the atmospheres. It was the process of photosynthesis that supplied oxygen to the atmosphere. How important oxygen is to us? Without oxygen it means we cannot breathe. How long can you hold without breathing? You can test it by putting your face into water. I did it. I can hold for one minute. It is extremely difficulty for me to hold for two minutes. The Guinness world record in 2008 is 14 minutes. However, most of people would die in less than ten minutes without breathing. So you see, without oxygen, we would die very quickly.
Secondly, photosynthesis provides the material and energy source for plants, animals and humans. Plants can grow by using solar energy through photosynthesis. But Animals and humans have to eat foods that are plants or other animals to survive. How important foods are to us? Some people in our club have already talked about nutrition and healthy foods. I enjoyed your speeches and I think I have learned a lot from your speeches. Naturally I would like to choose the foods that are good for my health. However, if you had not eaten any food for three days, I bet you would completely forget about nutrition and would possibly eat grasses and worms. Without food, we could hardly survive for one week.
Thirdly, fossil fuels, including oil, coal and natural gas are the products of photosynthesis. Why are they called fossil fuels? Because they formed from plants and animals that lived on earth millions of years ago. How important fossil fuels are to us? Recent information reveals that fossil fuels, oil, natural gas and coal provide us with 86% of the energy that we are consuming. Without fossil fuels, we not only cannot drive, but the industry would completely paralyze or collapse. Our way of living would have to go back up to that of three hundred years ago. Can you adapt to that kind of life? I don’t know whether I can adapt to it or not but I prefer the present life style. So without fossil fuels we could not enjoy our present life style.
Photosynthesis provides us with Oxygen, food and fossil fuels. We human did not design or create photosynthesis. Photosynthesis is a gift of nature or a gift of God if you like to see it from the angle of religion. No matter how photosynthesis originated, isn’t it a blessing for mankind?
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The above is a speech I delivered at my Toastmasters club. This five to seven minute speech is based on Toastmasters Competent Communication Manual, Project Seven: Research Your Topic.
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