Photosynthesis PDF

Have you ever thought about the fact that sunlight feeds the entire world? Through a photosynthesis, most plants and algae can do something animals cannot do; they make their own food! These green organisms use energy from sunlight and turn it into chemical energy. That energy feeds the world! Photo...

Have you ever thought about the fact that sunlight feeds the entire world? Through a photosynthesis, most plants and algae can do something animals cannot do; they make their own food! These green organisms use energy from sunlight and turn it into chemical energy. That energy feeds the world! Photosynthesis happens in the leaves of green plants. The ingredients needed for photosynthesis are carbon dioxide, water, and sunlight. There are small holes on the underside of a green leaf called stomata. These stomata allow carbon dioxide to enter the leaf. Water enters green plants through the roots. The roots pull water from the ground and carry it up the stem and into the leaves. The energy from sunlight is captured in a special structure called the chloroplast. You find chloroplasts inside the cells of green leaves. Chloroplasts hold an important substance called chlorophyll. Chlorophyll is a green pigment that takes in the light energy from the Sun and gives green plants their color. The chemical reaction of photosynthesis takes place here in the chloroplast. New products come from photosynthesis. These products are oxygen and a simple sugar called glucose. How are the glucose and oxygen made? First, the Sun’s energy breaks down the water into the elements hydrogen and oxygen. The hydrogen then combines with the carbon dioxide to make glucose. This sugar is food for the plant itself and animals that eat the plant. Oxygen is released back out through the stomata because the plant does not need it. There are six factors that change the rate at which photosynthesis happens. These are temperature, light intensity, light wavelength, level of carbon dioxide, amount of chlorophyll, and amount of water. The rate of photosynthesis is faster when four of these factors are at the right level: temperature, light intensity, carbon dioxide, and chlorophyll. The rate is also fast in light that is with more red or blue. Too little water slows the rate of photosynthesis. Photosynthesis is important to life on Earth because nearly all living things depend on plants. Here is the chemical equation for photosynthesis: 6CO2 + 6H2O ------> C6H12O6 + 6O2 Sunlight energy © Kesler Science, 2020