AIM SWBAT describe the 3 steps of the

AIM: SWBAT describe the 3 steps of the light independent reactions (Calvin Cycle) Please Do Now: Answer the following two questions: 1) What role does sunlight play in the electron transport chain? 2) Where do the electrons that are passed through the electron transport chain come from?

Agenda �Do Now �Data Analysis �Light Independent Cycle Notes �Video Clip �Finish Light Dependent Worksheet �Calvin Cycle Worksheet

Data Analysis �You will be a presented a series of graphs and charts (every Thursday) �For each chart or graph, on a blank sheet of paper you will answer 1 -2 questions (INDEPENDENTLY AND QUIETLY). �Once we have gone through all of them, you will be posed a question that unifies all the figures. Respond in 3 -4 sentences.

What colors are used in photosynthesis? : Chart 1 Color of Leaves Green Red Black Blue/Purple % of plants worldwide with that color 99. 78% 0. 17% 0. 01% 0. 04% � 1. What percent of plants worldwide have leaves that are some color other than green? � 2. What is the pigment that absorbs light for photosynthesis in plants?

What colors are used in photosynthesis? : Chart 2 �This graph details an experiment that tests photosynthesis. The more disks that are floating, the more photosynthesis is happening. � 1. What is measured on the Y axis? � 2. What is shown on the X axis? � 3. Which color of light has the most photosynthesis taking place? � 4. What color of light has the least photosynthesis taking place?

What colors are used in photosynthesis? : Chart 3 � 1. What is shown along the x axis? � 2. What colors of light have the highest % of absorption? � 3. What colors of light have the lowest % of absorption? % (color)

Putting it all together �In 2 -3 sentences, tell me what colors of light are used in photosynthesis and how you know that (cite specific graphs/charts).

Light Reactions EVEN MORE BRIEFLY � Sunlight in � Chemical Energy out � (ATP and NADPH)

Photosynthesis

Photosynthesis Chemical Energy

ALSO KNOWN AS DARK REACTIONS What is the purpose of the Light Independent Reactions �Uses the ATP from the light reactions �Takes place is the stroma of the chloroplast (outside thylakoid, inside the chloroplast). � 3 steps: 1. carbon fixation, 2. reduction 3. regeneration

Light Independent Reactions: Step 1 �Carbon fixation �The enzyme Ru. Bis. Co combines the 5 -Carbon compound Ru. BP with carbon dioxide (CO 2) to make an unstable 6 carbon compound

Light Independent Reactions: Step 2 �Reduction: The unstable 6 carbon compound is split apart and reduced into 2 molecules with 3 Carbons, called G 3 P �Requires ATP and NADPH

Light Independent Reactions Step 3 • Regeneration: A large array of enzymes rearrange 5 G 3 P molecules into 3 Ru. BP molecules, which start off the Calvin cycle � ATP required � 1 G 3 P can be taken out of the cycle every 3 turns, to go toward making glucose

Summary � 1 carbon dioxide is fixed per turn of the cycle �Each turn takes 3 ATP and 2 NADPH, made in the light reactions (lots of energy!) �To make one glucose, it takes six turns of the cycle

GOOD WORK!

Demo Time = carbon molecules (glucose has 6, Ru. BP 5, G 3 P 3, carbon dioxide 1) = ATP or NADPH molecules

Practice Questions �In the overall equation for photosynthesis, six molecules of carbon dioxide result in six molecules of a. glucose. b. water. c. oxygen. d. ATP.

The stroma is the space that surrounds a. thylakoids. b. chloroplasts. c. plant cells. d. all of the above

If carbon dioxide is removed from a plant’s environment, what would you expect to happen to the plant’s production of high-energy sugars? a. More sugars will be produced. b. Fewer sugars will be produced. c. The same number of sugars will be produced but without carbon dioxide. d. Carbon dioxide does not affect the production of high-energy sugars in plants.

�What is the role of Ru. BP in the light independent reactions? A. It reduces the 6 -carbon molecule and forms 2 G 3 Ps B. It provides the chemical energy for the regeneration step C. It is what carbon dioxide is fixed on to in the first step of the Calvin cycle D. It is one of the enzymes in the regeneration step

�It takes 3 molecules of ATP every turn of the Calvin cycle. How many molecules of ATP does it take to fix enough carbon for a 6 carbon molecule like glucose? �A. 9 �B. 18 �C. 27 �D. 54