Photosynthesis Why is Photosynthesis important? Makes organic molecules out of inorganic materials. It begins all food chains & webs. All life is supported by this process. It also makes oxygen gas! Photosynthesis- THE start to food webs! Photo-synthesis= “making things with light." Plants use sunlight to turn water and carbon dioxide into glucose. Plants use glucose as food Autotrophs make glucose and heterotrophs are consumers of it. Photosynthesis Carbon dioxide + water sunlight glucose + oxygen absorbed by chlorophyll 6CO2 + 6H2O + energy C6H12O6 + 6O2 Quick Read Turn to page 103 in your text Read through pages 103-105 Take some notes on what you read Pay attention to the graphics 1 chloroplast 6H 2O granum (stack of thy 2 6O2 thylakoid energ stroma (fluid y 6CO2 1 six-carb thylakoids) sugar CH O 3 4 6 12 chloroplast Chlorophyll is a molecule that absorbs light energy. • In plants, chlorophyll is found in organelles called chloroplasts. leaf cell leaf Photosynthesis in plants occurs in chloroplasts. Photosynthesis takes place in two parts of chloroplasts. grana (thylakoids) stroma grana (thylakoids) chloroplast stroma The light-dependent reactions capture energy from sunlight. – – – – take place in thylakoids water and sunlight are needed chlorophyll absorbs energy energy is transferred along thylakoid membrane then to light-independent reactions – oxygen is released The light-independent reactions make sugars. – take place in stroma – needs carbon dioxide from atmosphere – use energy to build a sugar in a cycle of chemical reactions The equation for the overall process is: 6CO2 + 6H2O C6H12O6 + 6O2 granum (stack of thylakoids) 1 chloroplast 6H2O thylakoid 6CO2 6O2 2 energy stroma (fluid outside the thylakoids) 1 six-carbon sugar C6H12O6 3 4 Chloroplast Structure Draw and label the thylakoid, granum, stroma, & outer membrane Step 1 Light Dependent Reaction • • • • What two things enter step 1? Where does step 1 occur? What two things leave step 1? Why is it called the light dependent reaction? Step 2 Light independent reaction • What two things enter step 2? • Where does step 2 occur? • What two things leave step 2? Elodea using photosynthesis What gas do you think is in the bubbles that the plant made? Plants in Action Glucose Two Steps of Photosynthesis Light Dependent Reactions (thylakoid) Sunlight is absorbed and converted to chemical energy Water is taken in and broken down into oxygen Chemical energy is temporarily stored in plants as ATP Light Independent Reactions (stroma) CO2, ATP, make organic compounds 6CO2 + 6H2O C6H12O6 + 6O2 Studying Photosynthesis Know what goes into each step and comes out of each step Know the different structures of the chloroplast Be able to label the diagram on the following slide Watch the following videos: Bozeman Science https://www.youtube.com/watch?v=g78utcLQrJ4 Animation with Explanation https://www.youtube.com/watch?v=wJDlxp17rY4 Crash Course https://www.youtube.com/watch?v=sQK3Yr4Sc_k