OCR Photosynthesis and Cellular Respiration PDF

1.2 Photosynthesis and Cellular Respiration  Learning Goals Describe what photosynthesis is Describe what cellular respiration is Explain how photosynthesis and cellular respiration are important for life on Earth Minds ON!  Energy Flow All organisms need ene...

1.2 Photosynthesis and Cellular Respiration  Learning Goals Describe what photosynthesis is Describe what cellular respiration is Explain how photosynthesis and cellular respiration are important for life on Earth Minds ON!  Energy Flow All organisms need energy to stay alive! Most of this energy comes from the sun (radiant energy) is energy from the sun Light is visible forms of radiant energy  Solar Radiation About 70% of the radiant energy is absorbed by the hydrosphere and lithosphere and converted to thermal energy. Thermal energy is what warms the atmosphere, evaporates water and produces winds. The remaining 30% of the radiant energy is reflected directly back into space. A small fraction of the radiant energy (0.023%) is absorbed directly by living organisms in a process called photosynthesis where it is converted into chemical energy Chemical Energy Chemical energy is stored in cells and then released when needed. Chemical energy is used by all organisms to perform functions, including movement, growth and reproduction.  Producers and Consumers Producers (green plants) create glucose or chemical energy from light energy. They do not need to consume other organisms to get energy. Consumers are organisms which need to eat (consume) other organisms to get their energy. They cannot perform photosynthesis.  Photosynthesis Virtually all of the chemical energy contained in food was once light energy captured in the process of photosynthesis. Photosynthesis is the process in which producers convert the Sun’s light energy into chemical energy stored in the bonds of sugars (glucose). Plants then use or store these sugars.  Photosynthesis Producers absorb carbon dioxide from the atmosphere, and take up water in their roots. Using the sun’s radiant energy, producers convert this into sugar and oxygen. The sugar contains the chemical energy the plants use for growth and other functions. Photosynthesis can be represented by the following word equation: sunlight carbon dioxide + water → sugar + oxygen  Photosynthesis Photosynthesis takes place in the chloroplasts. The chloroplasts is a part of the plants cells. It contains chlorophyll which is a green pigment that captures light energy in the process of photosynthesis.  Cellular Respiration Photosynthesis produces stored energy in the form of sugar. To make stored energy available for use, the plant performs a complementary reaction called cellular respiration.  Cellular Respiration Cellular respiration is a process that occurs in producers and consumers to provide energy to the cell. 1. Chemical bonds in glucose are broken to release chemical energy that can be used by the organism to grow, repair or reproduce Cellular respiration can be represented by the following word equation: sugar + oxygen → carbon dioxide + water + energy  Cellular Respiration Cellular respiration takes place in the mitochondria A.K.A the powerhouse of the cell Cellular Respiration Unlike photosynthesis, no light energy is required for cellular respiration, therefore this process occurs continuously. What do you notice?  Complementary Processes Cellular respiration and photosynthesis are complementary processes because the products of one reaction are the reactants of the other reaction. ie. CO2 and H2O are produced in cellular respiration and needed for photosynthesis to occur.