[MUSIC PLAYING]
Inside the common house
plant, a series of reactions
takes place that sustains
nearly all life on earth--
photosynthesis.
That's because the end
products of photosynthesis--
oxygen and carbohydrates--
are essential ingredients
for the survival
of most life forms.
The word "photosynthesis"
implies that the process
requires two sets of reactions.
"Photo," which
means light, refers
to the reactions in which
energy from the sun is captured,
and oxygen is released
through the atmosphere.
These reactions are called
the light-dependent reactions.
"Synthesis" refers
to the reactions
in which carbon dioxide
from the atmosphere
is used to build carbohydrates.
These reactions are the
Calvin cycle reactions.
In this lab, we'll explore
both of these reactions
by observing the process
of photosynthesis
in living plants.
We will explore the factors
that affect the oxygen produced
during the
light-dependent reactions
and investigate the
role carbon dioxide
plays in the Calvin
cycle reactions.
Before you begin, take a
look at the materials list
for this lab.
To observe
photosynthesis in action,
we will use two
different plants.
You will need two leaves
or sprigs from each plant.
For best results
in this experiment,
it is preferable
that your first plant
be a live aquatic plant, instead
of a common household plant.
In your lab manual, table 1
shows you various live plant
options.
You can find aquatic plants
in the aquarium supply section
of your local pet store.
Choose a variety that has
solid green leaves with plenty
of surface area for
absorbing light.
We will submerge
both plant types
in a bromothymol blue solution,
and measure the changes
in carbon dioxide in the
light and in the dark.
Although the actual
procedures for this experiment
will not take much time,
both require lengthy waiting
periods.
Also, this experiment
requires sunlight,
or a suitable substitute, so
consider the available lighting
as you plan for this lab.
Finally, make sure you
review the lesson activities
and textbook pages covering
photosynthesis before you
start the experiments.
Good luck.
