1 / 11

Biology20

Biology20. Photosynthesis Light Independent Reaction. The Second Step. Occurs in the stroma Does not require light Also called the Calvin Cycle Analyzed by a guy named Melvin Calvin This step uses CO 2 and H to form sugar!! CO 2 comes from the atmosphere

caden
Download Presentation

Biology20

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Biology20 Photosynthesis Light Independent Reaction

  2. The Second Step • Occurs in the stroma • Does not require light • Also called the Calvin Cycle • Analyzed by a guy named Melvin Calvin • This step uses CO2 and H to form sugar!! • CO2 comes from the atmosphere • H comes from NADPH of the Light Dependent Reaction • Originally came from water • Energy to drive this cycle is supplied by ATP from the Light Dependent Reaction.

  3. Steps in the Calvin Cycle 1) CARbon dioxide is fixed by RuBP • “Fixed” = to be incorporated into an organic molecule • RuBP = Ribulose Biphosphate • a 5 carbon sugar • acts as a CO2 acceptor • RuBP + CO2 = C6 sugar • This sugar is very unstable and immediately splits into two C3 sugars called PGA • PGA = phosphoglyceric acid

  4. Step 1 RuBP CO + 2 Unstable C Sugar 6 PGA (C ) 3 PGA (C ) 3

  5. Step 2 • PGA uses ATP as an energy source to remove hydrogen from NADPH to form a new molecule called PGAL • PGAL = phosphoglyceraldehyde • PGAL = C3

  6. ADP ADP ADP Step 2 NADPH ADP NADPH ADP ATP NADPH ATP ADP H H H ATP H ADP H PGA (C ) + H ADP P ATP 3 ADP P ATP ADP P ATP ATP ADP P ATP PGAL (C ) 3

  7. Fates of PGAL 1) In 6 Calvin Cycles, 12 PGAL’s (C3) are formed. • 2 are used to produce C6H12O6 • 10 are used to recycle into RuBP 2) PGAL can be used as an energy source in cell respiration 3) PGAL can be modified to produce fat or protein.

  8. Let’s Draw

  9. Light Dependent Reaction 6 CO2 [6] C6 Sugars [6] PGA (C3) [6] PGA (C3) ATP Energy RuBP NADPH H 10 PGAL [12] PGAL (C3) 2 PGAL • Protein Formation • Lipid Formation • Cellular Respiration Glucose

  10. Light Dependent Reaction 6 CO2 [6] C6 Sugars [6] PGA (C3) [6] PGA (C3) C Energy ATP [6]RuBP 5 NADPH H 10 PGAL [12] PGAL (C3) 2 PGAL • Protein Formation • Lipid Formation • Cellular Respiration Glucose

  11. Now that you’re smarter... Questions 17-22 p. 195 Review what you’ve learned by… completing your photosynthesis review sheet and completing your unit objectives handout

More Related