Transcript DO NOW
DO NOW Please hand in homework into the bin. Then Answer ◦ How do we see colors? ◦ Which color has the longest wavelength? The shortest? ◦ What pigments are in leaves? What colors do they reflect? ◦ What pigment do you think is in the graph? Photosynthesis Intro Video https://www.youtube.com/watch?v=eo5X ndJaz-Y Overview Of Photosynthesis Objectives To be able to list the inputs and outputs of photosynthesis. To be able to identify the structures in a chloroplast. To be able to summarize light-dependent reactions. Photosynthesis Light energy ------> chemical energy Used by autotrophs to produce food All of our energy starts as light energy! ◦ Plants use sunlight to make food animals eat plants other animals eat those animals Photosynthetic Organisms Go through Photosynthesis to produce GLUCOSE… Autotrophs -“Producers” in the food web Consist of plants, protists, cyanobacteria Photosynthesis Occurs in CHLOROPLASTS!! Requires the pigment chlorophyll to capture energy from light. Rearrange molecules of water and CO2 into new products The Chloroplast Structures within a chloroplast Thylakoids: flattened sac-like membranes arranged in stacks (stacks are called grana). Light-dependent reactions take place here. Electron transport occurs in the thylakoid membrane Stroma: Fluid filled space outside the grana. Light-independent reactions take place here. Starting Materials 1. Carbon Dioxide 2. Water 3. Sunlight Products! 1. Oxygen 2. Glucose! (C6H12O6) **Plants don’t immediately use all the glucose they make: ◦ Stored as STARCH!! Overall Chemical Equation Glucose Phase Overview 1) Light dependent Reactions ◦ Light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. (also produces Oxygen!) 2) Light Independent Reactions:(Calvin Cycle) ◦ CO2 ATP and NADPH are used to make glucose. *Glucose is the basic building block for more complex sugars such as starch.* Do Now Hand in your lab into the bin. Please make sure your name and your partners name is on it! Also grab four pieces of construction paper from my desk. Any color(s) of your choosing! Then answer: ◦ What are the reactants and products of photosynthesis? ◦ What is the equation for photosynthesis? Light Dependent Reactions Intro https://www.youtube.com/watch?v=BK_cj d6Evcw Light Dependent Reactions Step 1: Light energy reaches photosystem II causing the water molecule to split H H O H 2O H+ + O2 *H+ is released to the electron transport system. * O2 is given off as a byproduct. Step 2: Light energy reaches photosystem I and electrons flow from photosystem II to photosystem I. (to replace the electrons lost) Step 3: HYDROGEN IONS (protons) are pumped across the membrane into the thylakoid space as the electrons move through the electron transport chain. Step 4: Electrons from photosystem I move to a protein called FERRODOXIN **Ferrodoxin = “helper” protein** Step 5: Ferrodoxin transfers electrons to NADP+ forming NADPH. (Electron Carrier) ◦ We need this for the next part of photosynthesis! Step 6: Hydrogen ions move through the ATP SYNTHASE because of the concentration gradient, creating ATP. (Chemiosynthesis) To Calvin Cycle Chemosynthesis Mechanism in which ATP is produced as a result from the flow of electrons down a concentration gradient. ◦ Ex: Light reactions (H+ ions and ATP synthase) Light Dependent Reactions Location: Thylakoid Membrane in Chloroplasts! Inputs Outputs Light H₂O O₂ ADP ATP* NADP+ NADPH* **Goal Products! O₂ is only a byproduct!! Light Dependent Reactions Lets see it altogether now! https://www.youtube.com/watch?v=joZ1Es A5_NY Do Now Please garb the worksheet off my desk, and begin working on it individually. Do Now What are the steps of light dependent reactions? (yay light!) What is the equation for photosynthesis? Objectives List the inputs and outputs of the Calvin Cycle Define chemiosmosis and it’s role in photosynthesis. Summarize light – independent reactions Perform chromatography to identify the pigments of green leaves. Intro Video for Calvin Cycle https://www.youtube.com/watch?v=E_XQ R800AgM Light Independent Reactions (Calvin Cycle) Takes place in the stroma Functions like a sugar factory within a chloroplast ◦ **Regenerates the starting material with each turn Uses NADPH and ATP from Phase I (light dependent reactions) Needs CO2!!! Produces GLUCOSE Light Independent Reaction Calvin Cycle Step 1: Carbon dioxide molecules breakdown by combining with RuBP. (Carbon Fixation) Calvin Cycle Step 2: ATP and NADPH transfers energy and electrons to this molecule to create another three carbon molecule called G3P. Calvin Cycle Step 3: 2 G3P molecules will leave the cycle to create glucose. Calvin Cycle Step 4: An enzyme (Rubisco) converts the remaining G3P molecules into RuBP. ◦ RuBP will combine with new carbon dioxide molecules to continue the cycle. Calvin Cycle Inputs 6 CO2 - 18 ATP - 12 NADPH - Outputs - 2G3P (1 glucose- GOAL!) - 18 ADP - 12 NADP+ Location: Stroma of the Chloroplast QUICK! Which contains more energy, one molecule of NADP+ or one molecule of NADPH? What is the name of the three carbon molecule that is a product of the Calvin Cycle? Animation https://www.youtube.com/watch?v=joZ1Es A5_NY Let’s try some examples How many glucose molecules are made from 108 ATP in the calvin cycle? How many carbon dioxide molecules are needed to make 8 glucose molecules? Factors that can affect the rate of photosynthesis! Light Intensity (Amount) Rainfall Amount Temperature CO₂ Concentration Stomata can also affect the rate of photosynthesis! Stomata- openings (pores) on the underneath leaves that allow the exchange of carbon dioxide, oxygen, and water. More water available will open up stomata, less water will cause them to close to reduce water loss.