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.
12 s070201 i_photosynthesis
Photosynthesis orHow Plants Make Food
Energy from the Sun is necessary to begin the process.Besides green plants, some algae andbacteria can also make their own food.
Radiant energy from theSun, in the form of light,begins photosynthesis.Chlorophyll must also be present.
Water is taken into the plantby the roots and carried tothe leaves through the xylem . Xylem is a H20 H20 H20 series of tubes.
Carbon dioxide gas (CO2) istaken into the plant throughthe stomata on the undersideof leaves. CO2 CO 2 CO 2 H20 H20 H20
Oxygen gas (O2) is releasedinto the atmosphere throughthe stomata on theunder side of leaves. O2 O2 O2 H20 H20 H20
During photosynthesis,radiant (light) energy fromthe Sun is converted intochemical energy through achemical reaction. Theglucose (a type of sugar)that is produced is usedboth to keep the plantsalive and stored by plantsto be used by animals thatthen eat the plants.
Water vapor is released intothe atmosphere through thestomata on the leaves. 0 H2 H2 0 H 20This process is called transpiration.
Review the O2process. CO H 20 2 O2 0 H2 H2 0 O2 CO 2 H20 CO 2 H20 H20Explain each step as it is shown.
Remember, this process iscontinuous in O 2 CO H0 2light. O 2 2 0 H2 H2 0 O2 CO 2 H20 CO 2 H20 H20