Photosynthesis: Light Reaction and Calvin Cycle

Learning Objectives 

By the end of next week, you should be able to:

• • Write out the equation for photosynthesis.
  • Describe the process of the light reaction and the main ingredients and products.
    • How light energy is converted into chemical energy in the form of ATP
    • How water is used to generate Hydrogens that end up on NADPH
  • Describe the process of the Calvin Cycle
    • What is the main product and what it can be used for
    • What are ATP and NADPH used for in the Calvin Cycle 

Details of Cell Respiration 

WARNING:  If you go hunting around the internet, you will quickly see that these are very detailed processes. I have chosen the level of detail that I want you to know and understand.

Assignment 

 I have also created a handout for you to take notes as you follow along in the video below.  Your assignment will be to submit your handout, filled in to the best of your ability. You will probably have some questions!

Fill in this Handout as you watch the video. Download Fill in this Handout as you watch the video. You can submit it as a PDF or take a photo and upload the image. 

Photosynthesis

Chloroplast

Photosynthesis is the process of capturing light energy and using it to build organic molecules.  In order to do this a cell needs: 

• • • CO2, H2O = the raw ingredients needed to make organic molecules
    • Light = the energy for making the organic molecules ( building the chemical bonds)
    • Photosynthetic pigments= the machinery to capture light energy
    • Proteins and Enzymes for the two stages of photosynthesis- the machinery to make organic molecules. 

In plants, and other eukaryotic producers, this all takes place inside the chloroplast.  There are two  membranes surrounding a chloroplast- an outer and inner  membrane. There is a third membrane called the thylakoid membrane.  In this diagram, I've  labeled the membranes and what happens in each location. 

Light Reaction and Calvin Cycle

Photosynthesis is broken  into two different parts. The first is the Light Reaction and this captures the light energy and converts it  into chemical energy in the form of ATP. It also takes the hydrogens from water and puts them on a carrier  molecule called NADPH.

The second reaction is the Calvin Cycle.  This is a series of enzymes that take CO2 and build a 3 carbon sugar by attaching Hydrogens to the carbon (and obviously carbons to carbons). This requires energy in the form of ATP and Hydrogens that are provided by the NADPH.

Watch this video for more details. YFill in this Handout as you watch the video. Download Fill in this Handout as you watch the video. and submitt it for  your assignment.  We will go over it in class. 

Study Guide Questions 

1. Fill in the following chart

2. Write out the equation for photosynthesis. The reactants on the left side of the arrow and products on the right side. Note: if something is produced in the light reaction, but used up in the Calvin Cycle  and recycled, it shouldn't be put into this overall equation (ie NADPH).   Energy is traditionally written over the arrow and not as one of the reactants. 

3. Producers, like plants, are often called the ''base of the food chain''. Explain what this means  in terms of cellular respiration, photosynthesis and the ability of organisms to use organic molecules for energy or to build other organic molecules. . Make sure to use the following vocabulary: producers, consumers, photosynthesis, cell respiration, organic molecules, 3 carbon sugar, glucose,  amino acids,  nucleotides, fatty acids, macromolecules, growth and repair.