Photosynthesis

Photosynthesis—What Do We Already Know? Pass the Pen Have them independently brainstorm what they know, share in groups, write on board

Photosynthesis—Obtaining Energy Autotrophs use the process of photosynthesis to convert light energy into organic compounds.

How does a plant “breathe”? Stomata are openings in leaves (usually on the underside of the leaf). The Guard cells can open and close the stoma Carbon Dioxide is taken in through these stomata and water and oxygen are given off.

Chemical Equation—Quiz in 10 min! 6 6

Photosynthesis Brain Pop

Overview Photosynthesis Water Carbon Dioxide Sunlight/Photons Chloroplast Light Reactions Photosystem II Cytochrome Complex ATP Synthase Photosystem I Dark Reactions/Calvin Cycle Phase 1-Carbon Fixation Reduction Regeneration

2 Stages of Photosynthesis Light Reactions—In the Thylakoids Light Energy (from the sun) is converted to chemical energy, which is temporarily stored in ATP and the energy carrier molecule NADPH. Calvin Cycle—In the Stroma A series of enzyme-assisted chemical reactions that produces a three-carbon sugar.

Inside a Chloroplast Photosynthesis takes place inside a chloroplast The chloroplast contains saclike membranes called THYLAKOIDS THYLAKOIDS are arranged in stacks called GRANA The Chlorophyll is inside the thylakoids The STROMA is the region outside of the thylakoids

The first stage of photosynthesis is the LIGHT REACTIONS. Light is absorbed by the chloroplasts Light Energy is converted to Chemical Energy (stored in ATP and NADPH). This occurs in Photosystem II

Light Reactions Continued 3. Oxygen is given off during this reaction— Water is split! Oxygen is given off, Hydrogen ions remain and will be used later, and electrons are now available! --Leaf Demo-- Note--Chlorophyll in the chloroplast contains pigments (compounds that absorb light) that absorb a lot of blue and red light but reflect green light (giving plants their green color.)

Light Reactions Continued 5. An oxidation reaction takes place, losing electrons and the primary electron acceptor takes on the lost electrons in a reduction reaction—the electron transport chain begins! The primary electron acceptor donates the electrons to a series of molecules in the thylakoid membrane of the chloroplast.

Light Reactions Continued 7. As the electrons pass through the chain they lose energy. 8. Light is absorbed at this point and the electrons combine with a proton and NADP+ in Photosystem I 9. NADP+ is then reduced through another reduction reaction to NADPH (The Hs come from the splitting of water back in Photosystem II). NADPH will exit into the stroma via ATP Synthase where ATP is created and moves on to the Calvin Cycle

Making ATP in Light Reactions ATP is the energy in cells. The movement of protons into the stroma of the chloroplast releases energy, which is used to produce ATP. The energy is harnessed by an enzyme, ATP Synthase, which is in the thylakoid membrane

Draw it out! Diagram photosynthesis on doc camera, they copy

Photosynthesis—Light Reactions Video Clip 1st half of Biology Crash Course Photosynthesis

Light Reactions Video Clips Add to your summary if you need to! http://www.mhhe.com/biosci/bio_animations/02_MH_Photosynthesis _Web/ http://www.youtube.com/watch?v=hj_WKgnL6MI Light reactions by NDSU, about 5 min http://www.youtube.com/watch?v=CLf4yu8Iwo0, clay animation, just over a minute Animation from pinterest

INTERACTIVE 100-200 Words Summarize the LIGHT REACTIONS of photosynthesis

Light Reaction Diagram and Review With a partner (or in a group of 3 if needed), explain your diagram. Then switch. Draw out on board, kids also draw

Dark Reactions/Calvin Cycle In the second set of reactions in photosynthesis plants use the energy that was stored in ATP and NADPH during the light reactions to produce sugars. Most common way this is done is called the CALVIN CYCLE. Sciencemusic videos

Occurs in the STROMA of the chloroplast. Calvin Cycle A series of enzyme-assisted chemical reactions that produce a 3-Carbon Sugar. Occurs in the STROMA of the chloroplast.

Calvin Cycle— 3 Parts Carbon Fixation Reduction Regeneration

4 Steps of the Calvin Cycle 3 CO2 molecules diffuse into the stroma and combine with a 5-Carbon molecule, RuBP. This molecule is very unstable and it quickly splits into 2 3-Carbon molecules called 3- PGA. Each 3-PGA is converted into another 3 Carbon molecule, G3P after receiving a phosphate group from ATP and a proton from NADPH. Step 1 Step 2

4 Steps of the Calvin Cycle One of the G3P molecules leave the Calvin Cycle to make carbohydrates which are stored for later use. The remaining G3P molecules are converted back into RuBP by adding phosphate groups from ATP and then the Calvin Cycle begins again. Step 3 Step 4

Step 1—3 CO2 molecules combine to form RuBP (6 carbon molecule) with help from Rubisco which splits into 3 PGA Step 4– The rest of the G3P is converted back into RuBP/Rubisco Calvin Cycle Step 3– One molecule of G3P leaves the cycle to make sugars Step 2—Each molecule of 3 PGA is converted to G3P

Calvin Cycle Song!

Calvin Cycle Video Clip 2nd half of crash course

Calvin Cycle Draw it out! Explain it to a neighbor!

Calvin Cycle 100-200 Words Summarize the Dark Reactions of photosynthesis

INTERACTIVE Draw it out!

Photosynthesis Group Quiz

CFA Photosynthesis

Photosynthesis Case Study Sweet Beets case study

Photosynthesis: How is it Important to Medicine? Lab HASPI.org lab Use with honors and medical. With honors have them do the extension—design their own labs.

Design your own Photosynthesis Lab!

Photosynthesis Children’s Book Weekly HW?

Vocabulary Photosynthesis Electron transport chain Light Reactions Pigment Thylakoids Chloroplast Grana Calvin cycle Stroma Carbon fixation Photosystem Primary electron acceptor