PHOTOSYNTHESIS GUIDED NOTES
1. Photosynthesis defined:
2. Chemical reaction of photosynthesis:
3. What was von Helmont’s experiment? What did he conclude from it? What year?
4. What was the one thing von Helmont did not take into account?
5. What was Joseph Priestley’s contribution to the understanding of photosynthesis? What year?
6. What was Ingenhousz’s contribution to the understanding of photosynthesis? What year?
7. What molecule captures light?
8. What organelle of the cell is involved in photosynthesis?
9. Sketch a chloroplast in the space below. Label the thylakoid membrane, the stroma, granum, outer membrane.
9. What are the two main types of chlorophyll?
10. Are there any other pigments in leaves? What are they? How can you determine this?
Leaf structure:
1. The
parenchyma and
the organelles of the cell called
photosynthesis because of its large
parenchyma tissue is where the cells are that contain
that carry out photosynthesis. The leaf is the perfect structure for
area. The chemical reaction for photosynthesis is
2. Label the parts of the chloroplast.
3. There are two stages to photosynthesis, the
and the
cycle, which takes place in the
4. An average plant cells contains around
reactions which take place in the
.
to
chloroplasts. They contain the green pigment
. This pigment has electrons that are excited by
. Because the
pigment is green, it will not absorb wavelengths of light that are
. Instead, they will absorb wavelengths of
light that are
,
, and
. Other pigments found in the chloroplasts will
absorb the wavelength of light
. All these wavelengths are found in the part of the electromagnetic spectrum
known as the
. These pigments are found in
centers in the
proteins embedded in the
membrane of the thylakoid. The diagram below shows such a center.
According to this diagram, light is absorbed by the pigment molecules. The darker one at the 12:00 position is
.
All light energy captured is transferred from the other pigments to
.
5. The diagram below shows the two light reactions of photosynthesis. They are called photosystems I and II because they are
systems dependent upon the presence of
.
6. The P680 represents the wavelength of
that can be absorbed by each main
molecule in the
reaction center. The P700 in Photosystem I represents the wavelength of
that can be absorbed by the main
molecule in that reaction center.
7. As light hits the pigment molecules of Photosystem II, two
are given off from the main pigment
and a
protein known as the primary acceptor will transport the electrons down the electron transport chain.
Ions
will be pumped across the
membrane into the
space. The flow of energy
of these two electrons provides the energy to make
from
. In the meantime Photosystem I is also being zapped
with light which is being transferred to the main pigment
whose wavelength will absorb energy at
. Two
are lost from that molecule and carried by another primary acceptor in a shorter electron transport
chain that makes
.
8. The electrons lost from Photosystem II are replaced by the splitting of
into
ions. The gas exits the thylakoid, the chloroplast, the cell and the leaf through the
electrons lost from Photosystem I are replaced by those from
.
9. The two energy molecules formed during the light reactions are
in the next part of photosynthesis known as the
process.
and
cycle. No
gas and two
.The two
. These will then be used
is required for this part of the
From the diagram above, the H+ concentration is lowest in the
order for ATP to form, it must pass through the special enzyme
thylakoid membrane.
and highest in the
. In
found in the
10. Sugar (glucose) is made during photosynthesis during the
cycle. The products made during the Photosystems I
and II are used as the raw materials for this cycle. This is also where
gas enters the cycle. This is called
. A total of
of these molecules will enter the cycle from the atmosphere. This gas
has entered the plant and the cells and the thylakoids through the specialized openings in the leaves called the
.
This gas is then combined with 5 carbon molecules to produce glucose. In the entire cycle, it requires a total of
molecules of carbon dioxide gas,
molecules each of ATP and
molecules of NADPH to make
one molecule of glucose.
11. The factors that affect photosynthesis are



12. Because there are 3-carbon intermediate compounds formed during this type of photosynthesis, this type is called
Photosynthesis. The types of plants that carry out this type of photosynthesis are most of the plants and algae.
Some plants, like corn, sugarcane and crabgrass have evolved a different system, called
photosynthesis. In this
type,
gas is fixed in specialized cells called
sheath cells. This enables the cells to make sugar in
temperatures. 13. Another type of photosynthesis is called
for carassulacean acid metabolism. You would find
these in plants called
, which hold a lot of water. These plants open their stomates at
. Therefore you would find a lot of these plants carrying out photosynthesis in the
areas of the
world.