Man's physical universe



Coal, Oil, and Natural Gases Have Their Origin in Photosynthesis.

Plant and animal materials have been transformed by geological

processes involving high pressures and temperatures into such compounds

as coal, oil, and natural gas. Methods have already been

worked out for the direct conversion of carbohydrates such as cellulose

to hydrocarbons similar to those found in petroleum. Photosynthesis

may therefore be considered the "standby plant" to which we will

have to resort when our petroleum and coal resources are used up.

Man Has Not Yet Succeeded in Mastering Photosynthesis.

So far nearly every likely idea concerning the chemical mechanism

of photosynthesis has been proven to be wrong when tried

out, but

the intensive research now being carried out should yield some correct

answers soon.


1. Discuss photosynthesis as to (a) what it is, (b) why it is important, (c) what

products have their origin in it, and (d) man's present knowledge of it.

2. Upon what does the rate of photosynthesis depend?

3. Is man able to carry out artificial photosynthesis today?

4. What is necessar>' to prevent famines today?

5. Work out a hypothesis to explain the following observations: An active leaf

submerged in water and exposed to sunlight forms bubbles of gas on its

surface, the number of bubbles being proportional to the intensity of the


6. Differentiate between edible fats and oils, and mineral oils and waxes.

7. Why is photosynthesis spoken of as the most important chemical reaction

in the world?

8. Explain how coal, oil, natural gas, and petroleum have their origin in photosynthesis.

9. Why can animals not use hydrocarbons for foods?

10. List the most important organic acids and give the origin of each.

11. Add as many oils as you can to those mentioned in this lesson, and give the

uses of each.

12. Is it true that all living matter is dependent upon photosynthesis? Are

mushrooms an exception?

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