1. DO NOW!!  What is the difference between an autotroph and a heterotroph?  Why do plants need sunlight?  What gases are exchanged between plants and animals?  What is the difference between an autotroph and a heterotroph?  Why do plants need sunlight?  What gases are exchanged between plants and animals?

2. Overview Of Photosynthesis

3. 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.  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.

4. Photosynthesis  Process of converting light energy to 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  Process of converting light energy to 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

5. Photosynthetic Organisms  Go through Photosynthesis to produce GLUCOSE…  Autotrophs  “Producers” in the food web  Consist of plants, protists, cyanobacteria  Go through Photosynthesis to produce GLUCOSE…  Autotrophs  “Producers” in the food web  Consist of plants, protists, cyanobacteria

6. Photosynthesis: The Chemical Equation

7. Overview of Phases  1) Light dependent  Light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. (also produces oxygen as byproduct!)  2) Light independent (Calvin Cycle)  CO 2 ATP and NADPH (from light dependent) are used to make glucose.  1) Light dependent  Light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. (also produces oxygen as byproduct!)  2) Light independent (Calvin Cycle)  CO 2 ATP and NADPH (from light dependent) are used to make glucose. *Glucose is the basic building block for more complex sugars such as starch.*

8. Do Now!!  What are the two phases of photosynthesis?  What are the inputs and outputs of each phase?  What is the chemical equation for photosynthesis?  What are the two phases of photosynthesis?  What are the inputs and outputs of each phase?  What is the chemical equation for photosynthesis?

9. Objectives  To go over the steps of light dependent reactions  To understand the inputs and outputs of light dependent reactions  To label a light reactions diagram  To go over the steps of light dependent reactions  To understand the inputs and outputs of light dependent reactions  To label a light reactions diagram

10. Glucose

11. The Chloroplast

12. 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.  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.

13. Do Now!!  What is the equation for photosynthesis?  Where do light dependent reactions take place? Independent?  What are the inputs of light dependent reactions? The outputs?  What is the equation for photosynthesis?  Where do light dependent reactions take place? Independent?  What are the inputs of light dependent reactions? The outputs?

14. Objectives  To go over the steps of light dependent reactions  To understand the inputs and outputs of light dependent reactions  To label a light reactions diagram  To go over the steps of light dependent reactions  To understand the inputs and outputs of light dependent reactions  To label a light reactions diagram

15. Diagram!  Please grab 6 different colors!!  Lets label our light dependent reactions diagram.  Please grab 6 different colors!!  Lets label our light dependent reactions diagram.

16. Light Dependent Reactions  Step 1: Light energy reaches photosytem II, exciting electrons and causing water molecule to split. - H + is released, stays in thylakoid space. - O 2 is given off as a byproduct. - Electron released into electron transport system

17.  Step 2: Excited electrons move from photosystem II through the membrane  As they move, protons (H + ) are pumped into thylakoid space Light Dependent Reactions

18. Light Dependent Reaction  Step 3: At photosystem I, electrons are re-energized and transferred to ferrodoxin (helper protein):  NADPH (energy storage molecule) is formed from NADP+ (we need this for the Calvin Cycle!)

19. Light Dependent Reactions  Step 5: Hydrogen ions move through the ATP Synthase because of the concentration gradient, creating ATP from ADP. (Chemiosmosis)

20. Do Now!! What goes into a light dependent reaction? What is the goal of a light dependent reaction? What is given off as a byproduct? What is the name of the protein that converts NADP+ to NADPH? What goes into a light dependent reaction? What is the goal of a light dependent reaction? What is given off as a byproduct? What is the name of the protein that converts NADP+ to NADPH?

21. Objectives  To review light dependent reactions  To introduce light independent reactions by completing a Calvin Cycle activity  To review light dependent reactions  To introduce light independent reactions by completing a Calvin Cycle activity

22. Think-pair-share  Please work on the worksheet in front of you!  Try it by yourself, then you may work with a partner.  Please work on the worksheet in front of you!  Try it by yourself, then you may work with a partner.

23. Light Dependent Reactions http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html https://www.youtube.com/watch?v=joZ1EsA5_NY http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html https://www.youtube.com/watch?v=joZ1EsA5_NY

24. Do Now!!  Please take out the light dependent worksheet from yesterday!

25. Objectives  To identify the stages of light independent reactions  To identify alternative pathways  To define C4 and CAM plants  To identify the stages of light independent reactions  To identify alternative pathways  To define C4 and CAM plants

26. The Calvin Cycle  Takes place in the STROMA  Uses NADPH and ATP from Phase I (light dependent reactions)  Needs CO 2 !!!  Produces GLUCOSE!!  Takes place in the STROMA  Uses NADPH and ATP from Phase I (light dependent reactions)  Needs CO 2 !!!  Produces GLUCOSE!!

27. Calvin Cycle  Functions like a sugar factory within a chloroplast  Regenerates the starting material with each turn

28. Calvin Cycle Inputs -ATP -NADPH -CO 2 Outputs -Glucose Outputs -Glucose

29. Calvin Cycle

30. Chemiosmosis  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)  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)

31. Alternative Pathways  Light and Water can limit the amount of photosynthesis a plant can perform.  Some plants develop alternate pathways to maximize energy conservation.  Ex: CAM and C 4 plants.  Light and Water can limit the amount of photosynthesis a plant can perform.  Some plants develop alternate pathways to maximize energy conservation.  Ex: CAM and C 4 plants.

32. C 4 Plants  These plants minimize water lost  Turn CO 2 into a 4 carbon molecule instead of a 3 carbon molecule  Keeps stomata (plant cell pores) closed during hot days  Ex. Corn and Sugar Cane  These plants minimize water lost  Turn CO 2 into a 4 carbon molecule instead of a 3 carbon molecule  Keeps stomata (plant cell pores) closed during hot days  Ex. Corn and Sugar Cane

33. CAM Plants  Occurs in water-conserving plants that live in deserts and other arid environments  Stomata ALWAYS closed during the day  CO 2 only enters leaves at night, turns into a “storage molecule” until daytime  Ex. Orchids, cacti, pineapples