Lesson 4: Energy Flow in Ecosystems - Photosynthesis and Cellular Respiration - SNC1W - PDF

Energy Flow in Ecosystems Photosynthesis & Cellular Respiration Lesson 4 Unit 2 - Biology SNC1W  Learning Goals By the end of the lesson, I will be able to…  The Source of Energy The Sun is the source of almost all the energy liv...

Energy Flow in Ecosystems Photosynthesis & Cellular Respiration Lesson 4 Unit 2 - Biology SNC1W  Learning Goals By the end of the lesson, I will be able to…  The Source of Energy The Sun is the source of almost all the energy living things need to survive. Most of the Sun’s energy is radiant energy, which travels through empty space (vacuum) – About 30 % of the Sun’s energy is reflected by clouds or Earth’s surface – About 70 % is absorbed by the atmosphere, water, and land, and is converted into thermal energy – A very small amount is absorbed by living organisms ~ 0.023 %  The Source of Energy 30 % reflected 70 % absorbed 19 % absorbed by clouds and atmosphere 0.023 % absorbed 51 % absorbed by by plants land and oceans  Photosynthesis Some organisms use light to make their own food--autotrophic An organism that makes its own food is called a producer – plants are producers The process of converting light energy into chemical energy is called photosynthesis Plants are green because they contain chlorophyll, the chemical that absorbs light energy Some Producers in Ontario… Oak Tree White Pine Thistle White Paper Birch Columbine Clover Algae  Photosynthesis Reaction Light energy is used to convert two chemicals (carbon dioxide and water) to a different chemical (sugar) which is stored in the plant During photosynthesis, plants release oxygen We use a word equation to describe photosynthesis:  Cellular Respiration Many organisms do not produce their own food and must obtain energy from other sources--heterotrophic These organisms are called consumers, e.g. humans Consumers obtain energy by eating other organisms that contain stored energy As food is digested, the energy is released through a process called cellular respiration  Cellular Respiration Reaction In cellular respiration, the sugar and oxygen are changed into carbon dioxide and water As this occurs, energy is released We use a word equation to describe cellular respiration:  Complementary Processes Photosynthesis and cellular respiration are opposite reactions Both processes need to happen in order to sustain life Photosynthesis: - Plants only - (chloroplasts & chlorophyll) Cellular Respiration: -Everything! - (plants need to make their own energy too, right? Everything has mitochondria! Mitochondria cause cellular respiration to happen)  Practice Time! Complete the questions in the handout. Add to your vocabulary list Try the online quizzes and study jams Watch the videos posted