Photosynthesis Converting sunlight into chemical energy Students who

+ Photosynthesis: Converting sunlight into chemical energy Students who demonstrate understanding can: HS-LS 1 -5: Use a model to illustrate how photosynthesis transforms light energy into stored chemical energy.

+ n ✔ For Understanding To understand the process of photosynthesis we need to build off what we already know about: Topic Examples Molecules Water (H 2 O), Oxygen (O 2 ), Carbon Dioxide (CO 2) Carbohydrates Sugar (glucose) Trophic Levels Autotrophs, Heterotrophs, Primary Consumers Organelles of Plant Cells Nucleus, Cell Wall, Chloroplast, Mitochondria Energy Source for Cells ATP Cellular Respiration CO 2 is released into the atmosphere

+ In this lesson we will learn: n Sources of Oxygen n Autotrophs n Where photosynthesis happens n Structure of chloroplasts n Two reactions of Photosynthesis n Steps of Photosynthesis n Locations, Reactants and Products of the two process of photosynthesis n Photosynthetic Equation Driving Question: How does photosynthesis happen?

Try this: Lets all take a deep breath in and then slowly exhale out. Ready go! n Think-Pair-Share: Where do you think the oxygen (O 2) we breathe comes from? n O 2 is produced by different kinds of bacteria, algae, and plants (including trees) during photosynthesis. n About 25% of O 2 comes from land plants. So where does the other 75% come from? Well. . . n Most of Earth’s O 2 comes from the ocean. n Released from tiny ocean plants called, phytoplankton.

+ Autotrophs and Photosynthesis n Called “self feeders” or ”producers”. n Organisms that can produce their own food using light, water, carbon dioxide, or other chemicals. n Examples of autotrophs: green plants, some algae, few bacteria. n Most autotrophs use photosynthesis to make their food.

+ ✔ For Understanding n Class Discuss: Where does most of the O 2 we breathe come from? Did the answer surprise you? What is the difference between heterotrophs and autotrophs? n Think-Pair-Share: How do you think photosynthesis happens? What is needed for the process? n Excellent! Now lets learn about WHERE and HOW photosynthesis happens!

+ Class Discuss: What organelles are unique to plant cells? Where does photosynthesis take place in the cell?

Anatomy: Notice this organelle has a double membrane + Chloroplast (inner and outer) and has special structures inside. Inside the chloroplast are the sites of the two processes of photosynthesis. We will talk more about those sites in a couple slides!

First, lets learn more about chloroplast structure and functions! Structure Chlorophyll (pigment) Functions Allows plants to absorb energy from light Gives leaves their green color Protects and keep chloroplast structures enclosed Membrane Envelope Thylakoid membrane Granum Stroma Flattened sac-like membrane structures called thylakoids Thylakoids serve as the sites of conversion of light energy to chemical energy. Dense layered stacks of thylakoids Sites of conversion of light energy to chemical energy. Dense fluid within the chloroplast Lies inside the envelope but outside thylakoid membrane Site of conversion of carbon dioxide to carbohydrates Class Discuss: Why are plants green?

+ Now lets look at HOW photosynthesis happens: The processes of photosynthesis is categorized into two different reactions. These two reactions are called, light dependent reactions and light independent reactions. Light independent reactions are also referred to as Calvin Cycle. Steps of Photosynthesis https: //www. youtube. com/watch? v=g 78 utc. LQr. J 4 1. The pigment, chlorophyll, in the chloroplasts absorbs light energy provided by the sun. 2. Chloroplasts use the light energy to split water molecules into oxygen which gets released into the atmosphere for us to breathe. The light energy also starts the two reactions of photosynthesis. 3. Light Reactions: Capture light energy and uses electrons from the splitting of water to make ATP and NADPH 4. Light Independent Reactions: Use CO 2, ATP, and NADPH to make glucose.

Summary and Location of Reactions Light Dependent Reactions Location Reactants End Products Thylakoid Membrane 1. 2. Sunlight Water (H 2 O) 1. 2. 3. ATP NADPH Oxygen (O 2) Light Independent Reactions Location Reactants End Products Stroma 1. 2. 3. ATP NADPH Carbon Dioxide (CO 2) 1. Sugar (glucose) Class Discuss: What are the two reactions of photosynthesis? What pigment absorbs light energy? Think-Pair-Share: Do you think photosynthesis happens when its dark outside? Why or why not?

Summary and Photosynthetic Equation n This entire process can be summarized into a single chemical equation:

Think-Pair-Share: Why is photosynthesis essential to life on Earth? https: //www. youtube. com/watch? v=eo 5 Xnd. Jaz-Y Driving Question: How does photosynthesis happen? n Light energy gets converted into chemical energy. n Chemical energy is stored in the form of glucose (sugar). n Carbon dioxide, water, and sunlight are used to produce carbohydrates and oxygen. n Occurs in two stages: n Light Dependent Reactions n Light Independent Reactions