Photosynthesis Lecture Notes

University:
Winston-Salem Forsyth County Schools
Course:
AP Biology
Academic year:

2014
Views:

339

Pages:

11
Author:

Kaydence Glenn

Photosynthesis: Life from Light and Air Energy needs of life  All life needs a constant input of energy  Animals = Heterotrophs  get their energy from “eating others”  eat food = other organisms = organic molecules  make energy through respiration  Plants = Autotrophs  get their energy from “self”  get their energy from sunlight  build organic molecules (food) from CO2  make energy through photosynthesis Photosynthesis: the process that uses the sun’s energy to make simple sugars, such as glucose. 6CO2 + 6H2O → C6H12O6 + 6O2 Carbon Dioxide + Water → Glucose + Oxygen How do plants live?  Photosynthesis  Energy building reactions  collect sun energy  make ATP  Sugar building reactions  use ATP for energy  use CO2 as carbon for new sugars  build sugars  glucose, cellulose, starch  build all other organic molecules  proteins, lipids, carbohydrates, DNA  store energy for future use  starch in seeds & roots Photosynthesis  Actually 2 separate reactions  Energy building  use sunlight  make energy (ATP)  Sugar building  use ATP ADP sun Energy building reactions ATP Sugar building reactions  use CO2  make sugars (C6H12O6) CO2 sugar Chloroplasts CO2  absorb   sunlight & CO2 make energy & sugar Contain chlorophyll Light-Dependent Reactions H2O + light → ATP + O 2 energy H2O  makes ATP energy  releases oxygen sunlight Energy Building Reactions ATP O2 as a waste product Light-Independent Reactions CO2 + ATP → C6H12O6 + ADP CO2 ADP  builds sugars  uses ATP  cycles ADP back to Sugar make Building Reactions ATP sugars C6H12O6 more ATP Putting it all together CO2 + H2O + light → C6H12O6 + energy H2O CO2 sunlight ADP Plants make both:  ATP  sugars Sugar Building Reactions Energy Building Reactions ATP O2 O2 sugars C6H12O6 So what does a plant need?  Bring In leaves CO2  H2O  light  shoot  Let Out  O2  Move Around  roots sugars 6CO2 + 6H2O + light → C6H12O6 + 6O2 energy