Regents Biology Photosynthesis: Life from Light and Air

Regents Biology Plants are energy producers  Like animals, plants need energy to live  unlike animals, plants don’t need to eat food to make that energy  Plants make both FOOD & ENERGY  animals are consumers  plants are producers

Regents Biology How do plants make energy & food?  Plants use the energy from the sun  to make ATP energy  to make sugars  glucose, sucrose, cellulose, starch, & more sun ATP sugars

Regents Biology H2OH2O Building plants from sunlight & air  Photosynthesis  2 separate processes  ENERGY building reactions  collect sun energy  use it to make ATP  SUGAR building reactions  take the ATP energy  collect CO 2 from air & H 2 O from ground  use all to build sugars ATP sun sugars + CO 2

Regents Biology Using light & air to grow plants  Photosynthesis  using sun’s energy to make ATP  using CO 2 & water to make sugar  in chloroplasts  allows plants to grow  makes a waste product  oxygen (O 2 )

Regents Biology What do plants need to grow?  The “factory” for making energy & sugars  chloroplast  Fuels  sunlight  carbon dioxide  water  The Helpers  enzymes H2OH2O sugars ATP enzymes CO 2 sun

Regents Biology H2OH2O Photosynthesis ENERGY building reactions SUGAR building reactions ATP ADP CO 2 sugar sun used immediately to synthesize sugars

AP Biology  Chloroplasts  double membrane  stroma  fluid-filled interior  thylakoid sacs  grana stacks  Thylakoid membrane contains  chlorophyll molecules  electron transport chain  ATP synthase Plant structure outer membrane inner membrane thylakoid granum stroma

AP Biology Pigments of photosynthesis  Chlorophylls & other pigments  embedded in thylakoid membrane  arranged in a “photosystem”  Collection of pigment molecules embedded in a protein

AP Biology Photosynthesis  Light reactions  light-dependent reactions  energy conversion reactions  convert solar energy to chemical energy  ATP & NADPH  Calvin cycle  light-independent reactions  sugar building reactions  uses chemical energy (ATP & NADPH) to reduce CO 2 & synthesize C 6 H 12 O 6

AP Biology Light Reactions of Photosynthesis Photosystem IIPhotosystem I

AP Biology ETC of Photosynthesis  ETC uses light energy to produce  ATP & NADPH  go to Calvin cycle  PS II absorbs light  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!

AP Biology ETC of Photosynthesis  ETC uses light energy to produce  ATP & NADPH  go to Calvin cycle  PS II absorbs light  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

AP Biology ETC of Photosynthesis  ETC uses light energy to produce  ATP & NADPH  go to Calvin cycle  PS I absorbs light  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 split H 2 O Light Reactions of Photosynthesis O ATP to Calvin Cycle H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ e e e e sun

AP Biology From Light reactions to Calvin cycle  Calvin cycle  chloroplast stroma  Need products of light reactions to drive synthesis reactions  ATP  NADPH stroma thylakoid

AP Biology starch, sucrose, cellulose & more 1C CO 2 Calvin cycle 5C RuBP 3C RuBisCo 1. Carbon fixation 2. G3P Production 3. Regeneration of RuBP ribulose bisphosphate ribulose bisphosphate carboxylase 6 NADP 6 NADPH 6 ADP 6 ATP 3 ADP 3 ATP used to make glucose 3C G3P glyceraldehyde-3-P CCCCCCCCCCCCCCC 6C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC PGA phosphoglycerate CCCCCCCCCCCCCCCCCCCCC C C C 5C

AP Biology RuBisCo  Enzyme which fixes carbon from air  ribulose bisphosphate carboxylase  the most important enzyme in the world!  it makes life out of air!  definitely the most abundant enzyme

AP Biology Photosynthesis summary  Light reactions  produced ATP  produced NADPH  consumed H 2 O  produced O 2 as byproduct  Calvin cycle  consumed CO 2  produced G3P (sugar)  regenerated ADP  regenerated NADP

AP Biology Light Reactions O2O2 H2OH2O Energy Building Reactions ATP  produces ATP  produces NADPH  releases O 2 as a waste product sunlight H2OH2O ATP O2O2 light energy  +++ NADPH

AP Biology Calvin Cycle sugars CO 2 Sugar Building Reactions ADP  builds sugars  uses ATP & NADPH  recycles ADP & NADP  back to make more ATP & NADPH ATP NADPH NADP CO 2 C 6 H 12 O 6  +++ NADPATP + NADPHADP

AP Biology H2OH2O Energy cycle Photosynthesis Cellular Respiration sun glucose O2O2 CO 2 plants animals, plants ATP CO 2 H2OH2O C 6 H 12 O 6 O2O2 light energy  +++CO 2 H2OH2O C 6 H 12 O 6 O2O2 ATP energy  +++