Download Photosynthesis Notes – Part I

Photosynthesis Notes – Part I
Gathering Energy
Autotrophs – organisms that make their own food
“auto” = “___________” + “troph” = “energy”
Ex: ______________
Heterotrophs – organisms that obtain energy from food they consume
“hetero” = “________________” + “troph” = “energy”
Ex: ______________
Chemical Energy and ATP
Energy – comes in many forms
Ex: burning a candle  releases energy as ______________________________
Adenosine triphosphate (______) – main energy fuels for living things
“adenosine” = involves adenine and ribose
“tri” = “___________”, “phosphate” = involves ______________________
___________ ____________
_________________
Adenine – nucleotide (monomer for _______________________)
Ribose – 5-carbon sugar (also found as the sugar in __________)
Phosphate – molecules with phosphorus (also found in the “backbone” of __________________)
Storing energy
Adenosine diphosphate (______) has one less phosphate group
To store energy, a cell can add a phosphate group to ADP to form ATP
(______+ P + energy  _______)
ADP
ATP
Energy
Energy
Adenosine diphosphate (ADP) + Phosphate
Partially
charged
battery
Adenosine triphosphate (ATP)
Fully
charged
battery
Releasing Energy
To release stored energy, a cell can _______ the bond between the last phosphate groups.
(above reaction is reversed: _____  _____ + P + energy)
Investigating Photosynthesis
- Van Helmont’s Experiment (1600s) – placed seedling into a pot of soil, watered it, and let it
grow, without changing the soil
o Found that after five years, the plant grew to be ________, but the mass of the
______ had not really changed
 A little lost due to _____________________________ leaving the soil
o He assumed that the mass the plant gained was due to _____________
o He did not realize that majority of its mass actually came from the air because
_______________________ is converted into sugar (a _______________________)
by the plant during ____________________________
- Priestley’s Experiment (1771) – placed a lit candle under a jar, and it went out when the
_______________ was all used up
o He then placed a ______________ under a glass jar with a candle, and it continued
burn, because the plant released the _________________ needed to keep the candle
burning.
- Jan Ingenhousz (1779) – continued Priestley’s experiment in the ___________
o He found that _____________ was necessary for plants to produce _______________
The Photosynthesis Equation
Light Energy
Light
6CO2 + 6H2O

C6H12O6 + 6O2
Light
_______________________ 
-
-
______________________
Photosynthesis uses the energy of ____________________
to convert water and carbon dioxide into high-energy sugars
and oxygen
Plants then use the sugars to create complex carbohydrates
like _____________
CO2 + H2O
Plants obtain _______________________ from the
air or water in which they grow, and this increases the size of the plant
Chloroplast
C6H12O6 + O2
Light and Pigments
- in addition to water and carbon dioxide, photosynthesis requires light and
______________________, a molecule in chloroplasts
- “white light” is actually many different colors of light (ex: ___________________________)
-
Pigments – ______________-absorbing molecules in plants
Chlorophyll – main plant pigment
o Does not absorb ______________ well – it is ________________ by the leaves
When chlorophyll absorbs light, the ____________________ is stored in the chlorophyll