Download Photosynthesis

Photosynthesis
Lab 5
Objetives
• Write an overall summary of photosynthesis,
using only the terms carbon dioxide, chlorophyll,
light, oxygen, sugar, water.
• Summarize the products of the light-dependent
and the light-independent reactions of
photosynthesis.
• Determine the effects of various external factors,
light intensity, CO2 concentration, and water
(optional:color of light, temperature) on the rate
of photosynthesis.
• Determine the relationship between the light and
dark reaction.
Plant cell
• Photosynthesis is the manufacture of organic
food materials from inorganic raw materials. It
is performed by green plants.
• The chlorophyll in plants enables them to use
the energy of light in the food manufacturing
process. The plant can then use the organic
materials it manufactures for growth or for the
production of molecules necessary for other
processes.
• A simplified equation for photosynthesis is:
light
• 6H2O + 6CO2
inorganic raw material
→
chloroplasts
H12O6 +
6O2
Food
Waste
product of this
reaction
The process of photosynthesis takes
place in the chloroplasts; reactions occur
at the thylakoid membrane and in the
stroma.
Parts of the chloroplasts: - Stroma
- Thylakoid
- Granum (stack of
thylakoids)
- Intermembrane space
- Inner membrane
- Outer membrane.
There are two sets of reactions making
up photosynthesis:
• Light-dependent reactions (thylakoid
space) which produce oxygen (photolysis),
NADPred, and ATP. The NADPRed, and
ATP are used in the light-independent
reaction.
• Light-independent reaction (stroma)
produces the carbohydrates (also called
the Calvin-Benson cycle).
• The basic mechanism of photosynthesis is
the capture of light energy and its storage
in the chemical bonds of sugars (and their
derivatives)
• This stored energy can be used by the
plant for growth or for staying alive. It can
also provide food for animals.
• In this activity you will begin to probe
“inside” photosynthesis, to discover just
how plants actually accomplish sugar
synthesis.
• You will simulate a number of experiments
in order to better understand the steps in
photosynthesis.
Procedure
• Open the lab file: A Closer Look.
• Is you need help operating this program, please
refer to “An Overview of the Explores Control
Tools” located on the last two pages of this
experiment. There is a more detailed “Overview
of the Explorer Control Tools” in the last section
of this manual.