Section: 3.2 Name: Opening Activity: What type of energy is absorbed by pigment molecules in plant cells to start photosynthesis? Latin Root Word: Review of Old Information: ATP then provides the energy needed for our cells to carry out their functions. The following is a review of what we have learned about ATP so far: : adenosine triphosphate Made up of adenosine + 3 phosphate groups : Adenosine diphosphate Cells recycle the ADP to make new ATP to store more energy for future use Many proteins have spots where ATP attaches to provide energy for the protein to do its job, then the ADP is released for recycling New Information: Complete the notes on photosynthesis in the spaces below. Photosynthesis: Process that uses the s energy to make glucose Carried out by green plants and some bacteria Purpose is to trap sun s energy and store it in (food for the plant or animals) Photosynthesis occurs in the.
Thylakoids are green because they contain. Chlorophyll: green in plants that absorbs light energy. : light-absorbing compound Chemical equation for photosynthesis: 6CO2 + 6H2O + light energy C 6H 12O 6 + 6O2 (carbon dioxide + water + sunlight glucose + oxygen) Steps of photosynthesis: Step 1: Light Reactions a. Overall Reaction: Light energy NADPH and ATP b. This reaction takes place in the thylakoid membrane! c. Step 1: i. White light is actually a combination of all light ii. Different pigments in the chloroplast can absorb different types of light a. Chlorophyll a absorbs mostly b. Chlorophyll b absorbs mostly c. Carotenoids some d. Step 2: i. The absorbed light is used to excite electrons in pigments ii. These excited electrons and water are used to fuel two biochemical pathways 1. a. Every cycles produces one NADPH 2. a. Produces ATP e. Step 3: = makes ATP from H+ that are released by water
REPLACING ELECTRONS -Pigments that gave up electrons get replacements from? - molecules are split and oxygen is released to the atmosphere. Then -H+ go the thylakoid membrane and from water are replaced in photosystem II Summary: Light reactions (Light-dependent reaction) This first step of photosynthesis traps sunlight and makes electrons (stored in ) and to run the dark reactions. 1. Dark reactions (also called Light-independent reaction or Cycle )
The second step of photosynthesis uses ATP and electrons from the light reactions and from the air to make.
Activity: PHOTOSYNTHESIS STARTS WITH 1. Molecules that collect light energy are called _P. 2. Chlorophyll a and b absorb _B -_V and _R wavelengths of light best. 3. _C is the main light absorbing pigment found in green plants. 4. Plants look green because chlorophyll _R green light. 5. Organisms, like green plants, that can make their own food using energy from the sun are called _A. 6. The gel-filled space inside the chloroplast surrounding the thylakoid stacks is called the _S. 7. _P I and II contain chlorophyll and absorb light energy during the _L D reactions. 8. During the light dependent reactions, H + ions build up in the _T space when _W molecules are split. 9. The enzymes for the light dependent reactions are found in the _T M, while the Calvin cycle happens in the _S. 10. The stacks of thylakoids found inside chloroplasts are called _G. 11. The light independent reactions are also called the _C _C. 12. Carbon and oxygen from _C _D end up as part of a _G molecule following the Calvin cycle.
13. _A and _N are made during the _L dependent reactions and carry energy and high energy electrons that are used during the Calvin cycle to produce _S, like glucose. 14. The O in H 2 O is given off as_o gas to the atmosphere when water is split during the light dependent reactions. 15. Proteins in living things that help chemical reactions happen are called _E. 16. Electrons are transferred along the membrane from Photosystem II to Photosystem I using the _E _T S. 17. The movement of H + ions from the thylakoid space, across the membrane, and into the stroma causes _A S to spin and produce ATP, 18. _J I showed that plants only produce oxygen when exposed to light. 19. Orange and yellow colored pigments called _C absorb different wavelengths of light and help chlorophyll use more of the sun s energy. 20. _T, amount of _W, and _L intensity are all factors that affect the rate of photosynthesis.