Transcript Balancing Equations??? Not Again….. Writing Prompt ~ 12.19.2008

Balancing Equations??? Not Again…..
Writing Prompt ~ 03.11.2009
• Look carefully at this equation. What does this equation relate
to? Explain how you came up with your answer…
CO2 + H2O + light  Glucose + O2
Reactants
Products
Balance the equation…..
• ____CO2 + ____H2O + Light  1C6H12O6 + ___O2
Where does this reaction occur?
Photosynthesis
• It is the conversion of solar energy to
chemical energy in a form that can
be utilized by living organisms.
• 2 steps
– Light reaction - Light Dependent
reaction
– Calvin cycle - Light Independent
reaction
• occurs in the light as well as the dark
What’s the Ultimate energy source?
• The sun is ultimate energy
source for virtually ALL life
on earth.
• Plants and Cyanobacteria
generate their own food by
converting SOLAR energy
to the stored energy of
glucose (food & building
materials).
• Plants and animals must
then convert that food to
an energy form useable at
the cellular level.
Equation for Photosynthesis
CO2 + H2O + light -----> Glucose + O2
Reactants
Products
Where does this reaction occur?
Where do these inputs come from?
• Energy (light) comes
from the sun (or some
other artificial light
source.
• Water comes from the
soil into the plant roots
& through the plant to
the leaves.
• Carbon Dioxide
comes from the air and
enters the leaves
through stomata.
Light Dependent Reaction
• Light strikes chloroplasts of a leaf cell
• Energy from light energizes chlorophyll
• Energized chlorophyll splits a water
molecule, giving off the oxygen as a gas
(waste) and capturing the hydrogen atoms
to use later.
• This is the place where you’ve learned that
plants give off oxygen!!
Calvin Cycle
(Light Independent Reaction)
• The fixation of carbon dioxide from
atmosphere to make sugar (storing carbon
to use for building / growing)
• Light is NOT necessary for this reaction- it
takes place both during the day and at
night
• Combines CO2 with other carbon
containing compounds form to sugar Glucose (6 carbons)
• When you learned that plants take in CO2
(carbon dioxide) this is where its used.
What kinds of light are
involved?
Check it out…..