Photosynthesis PDF

Today we will be talking about photosynthesis! The subtitle “Living things and energy” talks about what living things need. For example, all living things need energy. Cells in every organism need energy to carry out functions, such as making proteins and transporting substances into and out of the...

Today we will be talking about photosynthesis! The subtitle “Living things and energy” talks about what living things need. For example, all living things need energy. Cells in every organism need energy to carry out functions, such as making proteins and transporting substances into and out of the cell. Energy comes from the environment similar to the raw materials cells use to function, such as kelp, sea urchins, and otters. Animals use organisms for food. Plants and certain organisms use energy from the sunlight to make their own food. Another subtitle is “Energy from the Sun” and it talks about photosynthesis. Photosynthesis comes from the Greek work photos (light) and syntithenal (putting together). Photosynthesis is a chemical reaction in plants that takes place mostly in chloroplasts. Plants use the sun’s energy during photosynthesis to convert carbon dioxide and water into sugar, oxygen is a by-product. Because photosynthesis is a chemical reaction, several different factors affect the rate of chemical change. The availability of sunlight, water, and carbon dioxide are all factors required for photosynthesis. All takes place in the organelle which is chloroplast. Chlorophyll is the green pigment found inside the chloroplast. The 1st stage concludes with 3 steps. Water and solar energy go into the chloroplast. The sunlight splits the water molecules into hydrogen and oxygen. Hydrogen goes to stage 2 and oxygen leaves the cell as waste. Stage 2 also concludes with 3 steps. Hydrogen from stage one goes through a reactant (substance that goes through a change during a reaction). Carbon dioxide is another reactant. Both carbon dioxide and hydrogen go through a series of reactions to produce glucose. Another subtitle is called “Expressing Photosynthesis”. Things on the left are raw materials (or reactants). The items on the right are products. Energy is not a raw material but it is shown on the left side because it is used in reaction. Plant cells use some of the glucose produced for food. The cells break down sugar molecules in a process called cellular respiration. Some energy can be used to carry out a plant’s functions by growing, making seeds, made into other compounds (cellulose for cell walls), and some are stored for later use. Another subtitle is “Importance of plant cells”. Plant cells were the first type of cells to be discovered with a microscope. Marsh plants help soak up water. For this reason, marshland is considered a natural flood control. Plants and algae that live in water absorb about one-sixth of the sun’s energy. Ocean plants help recycle 8.5 percent on Earth.