2. Energy from the Sun is
necessary to begin the
process.
Besides green plants, some algae and
bacteria can also make their own food.
3. Radiant energy from the
Sun, in the form of light,
begins photosynthesis.
Chlorophyll must also be present.
4. Water is taken into the plant
by the roots and carried to
the leaves through the xylem .
Xylem is a
H20
H20 H20 series of
tubes.
5. Carbon dioxide gas (CO2) is
taken into the plant through
the stomata on the underside
of leaves. CO2
CO 2
CO 2
H20
H20 H20
6. Oxygen gas (O2) is released
into the atmosphere through
the stomata on the
under side of leaves.
O2 O2
O2
H20
H20 H20
7. During photosynthesis,
radiant (light) energy from
the Sun is converted into
chemical energy through a
chemical reaction. The
glucose (a type of sugar)
that is produced is used
both to keep the plants
alive and stored by plants
to be used by animals that
then eat the plants.
8. Water vapor is released into
the atmosphere through the
stomata on the leaves.
0
H2
H2
0
H 20
This process is called transpiration.
9. Review the O2
process.
CO
H 20
2
O2
0
H2
H2
0
O2
CO 2
H20 CO 2
H20
H20
Explain each step as it is shown.
10. Remember, this process is
continuous in O 2
CO
H0
2
light. O
2
2
0
H2
H2
0
O2
CO 2
H20 CO 2
H20
H20
Notas do Editor
Organisms that make their own food are called autotrophs. There are only a few organisms, other than green plants, that can do this.
Radiant energy is energy traveling in waves for example electromagnetic radiation, as heat, light, or x-rays. All components of photosynthesis may be present, but without the plant pigment chlorophyll no photosynthesis will take place.
Introduce students to the terms xylem and phloem. They do not need to memorize these terms. Xylem is a series of tubes which carry water and minerals up to the leaves. Phloem is plant tissue that conducts and distributes sugars from the places where the food is produced to the places where it is needed or stored.
To avoid misconceptions from developing, remind students that carbon dioxide is always in the air and that plants to not use all the CO 2 available.
Oxygen is a product of the process of photosynthesis.
Glucose (sugar) is also a product of photosynthesis.
Water in the form of vapor (gas) is a product of photosynthesis.