 What is the difference between an autotroph and a heterotroph?  Why do plants need sunlight?  What gases are exchanged between plants and animals?

 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.

 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 those animals

 Go through Photosynthesis to produce GLUCOSE…  Autotrophs  “Producers” in the food web  Consist of plants, protists, cyanobacteria

 1) Light dependent  Light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. (also produces Oxygen!)  2) Light Independent (Calvin Cycle)  CO 2 ATP and NADPH are used to make glucose. *Glucose is the basic building block for more complex sugars such as starch.*

Glucose

 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.

 Step 1: Light energy reaches photosytem II causing the water molecule to split O H H H2OH2O H+H+ O2O2 + *H + is released to the electron transport system. * O 2 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 as the electrons fall. (think of a hyper child losing energy)

 Step 4: Electrons from photosystem I move to a protein called ferrodoxin. **Ferrodoxin = “helper” protein**

 Step 5:Ferrodoxin transfers electrons to NADP+ forming NADPH. (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. (Chemiosmosis) To Calvin Cycle

Lets see it altogether now! ology/Bio231/ltrxn.html

 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 needed in a light dependent reaction?

 In what part of the chloroplast do light reactions occur?  What are the outputs of light-dependent reactions?  What is the name of the cycle in light- independent reactions?

 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.

 Takes place in the stroma  Uses NADPH and ATP from Phase I (light dependent reactions)  Needs CO 2 !!!  Produces GLUCOSE

 Functions like a sugar factory within a chloroplast  **Regenerates the starting material with each turn

Inputs - ATP - NADPH - CO 2 Outputs - Glucose

 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 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.

 Biology/Bio231/calvin.html Biology/Bio231/calvin.html