Photosynthesis Life from Light and Air Regents Biology
Photosynthesis: Life from Light and Air Regents Biology 2006 -2007
Plants are energy producers § Like animals, plants need energy to live u unlike animals, plants don’t need to eat food to make that energy § Plants make both FOOD & ENERGY animals are consumers u plants are producers u Regents Biology
How do plants make energy & food? § Plants use the energy from the sun to make ATP energy u to make sugars u § glucose, sucrose, cellulose, starch, & more sun ATP sugars Regents Biology
Building plants from sunlight & air § Photosynthesis 2 separate processes u ENERGY building reactions sun u § collect sun energy § use it to make ATP u ATP SUGAR building reactions § take the ATP energy § collect CO 2 from air & H 2 O from ground § use all to build sugars H 2 O + CO 2 sugars Regents Biology
Using light & air to grow plants § Photosynthesis using sun’s energy to make ATP u using CO 2 & water to make sugar u in chloroplasts u allows plants to grow u makes a waste product u § oxygen (O 2) Regents Biology
What do plants need to grow? § The “factory” for making energy & sugars u sun chloroplast § Fuels CO 2 sunlight u carbon dioxide u water u § The Helpers u enzymes Regents Biology H 2 O ATP enzymes sugars
Photosynthesis sun ENERGY building reactions ATP ADP SUGAR building reactions H 2 O Regents Biology used immediately to synthesize sugars sugar CO 2
Plant structure § Chloroplasts u u double membrane stroma outer membrane inner membrane § fluid-filled interior u u thylakoid sacs grana stacks stroma § Thylakoid membrane contains u u u AP Biology chlorophyll molecules electron transport chain ATP synthase thylakoid granum
Pigments of photosynthesis § Chlorophylls & other pigments u u embedded in thylakoid membrane arranged in a “photosystem” § Collection of pigment molecules AP Biology embedded in a protein
Photosynthesis § Light reactions light-dependent reactions u energy conversion reactions u § convert solar energy to chemical energy § ATP & NADPH § Calvin cycle light-independent reactions u sugar building reactions u § uses chemical energy (ATP & NADPH) to reduce CO 2 & synthesize C 6 H 12 O 6 AP Biology
Light Reactions of Photosynthesis Photosystem II Photosystem I AP Biology
ETC of Photosynthesis § ETC uses light energy to produce u ATP & NADPH § go to Calvin cycle § PS II absorbs light u u u AP Biology excited electron passes from chlorophyll to “primary electron acceptor” need to replace electron in chlorophyll enzyme extracts electrons from H 2 O & supplies them to chlorophyll § splits H 2 O § O combines with another O to form O 2 § O 2 released to atmosphere § and we breathe easier!
ETC of Photosynthesis § ETC uses light energy to produce u ATP & NADPH § go to Calvin cycle § PS II absorbs light u u u AP Biology excited electron passes from chlorophyll to “primary electron acceptor” Electron passes down ETC Each time electron is passed, releases a little E E is used to pump H+ from stroma into thylakoid H+ diffuse down conc. gradient back into stroma Pass through ATP Synthase, allowing it to make ATP
ETC of Photosynthesis § ETC uses light energy to produce u ATP & NADPH § go to Calvin cycle § PS I absorbs light u u excited electron passes from chlorophyll to “primary electron acceptor” need to replace electron in chlorophyll Electron comes from ETC of PSII Excited electron passes to electron carrier molecule § NADPH § Sent to Calvin Cycle in the stroma AP Biology
Light Reactions of Photosynthesis sun e e sun O split H 2 O H+ + H+ H + H+ +H H+ H+ H to Calvin Cycle ATP AP Biology
From Light reactions to Calvin cycle § Calvin cycle u chloroplast stroma § Need products of light reactions to drive synthesis reactions ATP u NADPH u thylakoid AP Biology stroma
C Calvin cycle 1 C C C 3. Regeneration C C C of Ru. BP starch, sucrose, cellulose & more ribulose bisphosphate AP Biology C C C C C Ru. Bis. Co ribulose bisphosphate carboxylase 3 ADP used to make glucose CO 2 5 C glyceraldehyde-3 -P G 3 P C C C 3 C 6 NADP 6 C PGA phosphoglycerate 2. G 3 P Production 6 NADPH 1. Carbon fixation C C C 5 C 3 ATP C C C C 3 C C C C C 6 ATP 3 C 6 ADP
Ru. Bis. Co § Enzyme which fixes carbon from air ribulose bisphosphate carboxylase u the most important enzyme in the world! u § it makes life out of air! u AP Biology definitely the most abundant enzyme
Photosynthesis summary § Light reactions produced ATP u produced NADPH u consumed H 2 O u produced O 2 as byproduct u § Calvin cycle consumed CO 2 u produced G 3 P (sugar) u regenerated ADP u regenerated NADP u AP Biology
Light Reactions light ATP + NADPH + O 2 energy H 2 O + H 2 O sunlight Energy Building Reactions NADPH ATP AP Biology O 2 § produces ATP § produces NADPH § releases O 2 as a waste product
Calvin Cycle CO 2 + ATP + NADPH C 6 H 12 O 6 + ADP + NADP CO 2 ADP NADP Sugar Building Reactions NADPH ATP AP Biology sugars § builds sugars § uses ATP & NADPH § recycles ADP & NADP § back to make more ATP & NADPH
Energy cycle sun Photosynthesis light CO 2 + H 2 O + energy C 6 H 12 O 6 + O 2 plants CO 2 H 2 O glucose animals, plants ATP C 6 H 12 O 6 + O 2 energy + CO 2 + H 2 O Cellular Respiration ATP AP Biology O 2
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