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PHOTOSYNTHESIS: PRODUCTS


We have already discovered two products made as a result of photosynthesis. The leaf factory made oxygen and starch. Plant leaves are also the beginning of many other important foods. Let's see if we can discover how plants can make fats, oils, proteins, and vitamins.

Here are your goals for this lesson:

Use an equation to represent photosynthesis
Describe how glucose is used to make starch, fats, and proteins


VOCABULARY
enzyme Chemical which helps speed up organic reactions
glucose Sugar made during photosynthesis.
legume A protein-making plant.
ptyalin Enzyme that breaks down starch into glucose.
Vocab Arcade


LOCATION



Direct. Some of the leaf factory products are made directly from photosynthesis. Certain enzymes in plants can break down starch into a simple sugar called glucose. The saliva in your mouth contains a chemical called an enzyme. Its name is ptyalin. Ptyalin has the ability to break starch into a simple sugar called glucose. Plants and animals use glucose for energy to do work. We know it saves space to stack blocks neatly together. It is also easier and more efficient to stack glucose together as starch until the energy is needed. As many as one thousand glucose units can be stacked together to form one starch unit. These starch units are reservoirs of energy and can be compared to a chemical battery. Although the leaf factory produces starch, the leaf actually makes glucose first and then stacks up the glucose to save room. Our leaf factory could more accurately be stated:



Indirect. Glucose can be used by plants to make many other foods. One example of these foods is fats and oils. Some of the most important foods are oils from olives, coconuts, peanuts, and cotton. Often, the fats and oils are stored in the seeds. This high-energy food is used by the seeds at germination time to get the growth process started. This is similar to the energy stored in the battery of a car. The car's engine needs this burst of energy to get started. This use is the Creator's way of making sure that each seed has enough food energy to grow until the new plant can produce its own food.

Proteins (nitrogen compounds) are also made from simple glucose. The making of proteins is very complex. Some types of plants, the legumes, are very good protein makers. They have a special bacteria in the roots to help them get the nitrogen compounds necessary for making protein. Beans, peanuts, alfalfa and soybeans are common examples of legumes. Plants like these are very important in helping us meet our world hunger problems. They provide a nearly balanced diet.

Plants are excellent sources of vitamins. Unlike animals, plants can make and store vitamins. Green leafy vegetables are very good for our diet because of the vitamins. Vitamin A is found in sweet potatoes, carrots, and lettuce. Vitamin B is found in seeds from grain such as wheat, oats, and barley. Citrus fruits and fresh vegetables have a lot of vitamin C.