EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Photosynthesis is the process by which

plants use the sun’s energy to convert water and carbon dioxide into sugars.

Read “Energy” p. 327 – 329 Take Notes!

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Energy is the ability to do work. Kinetic energy is the energy of motion Potential energy is energy that is stored

due to an object’s position or arrangement.

Energy can be converted from one form to another.

Different types of energy – chemical, light, electrical, mechanical, thermal

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Organic molecules have a form of

potential energy called chemical energy

Chemical energy has the potential to do work due to the arrangement of the atoms within the molecules.

The rearrangement of atoms during chemical reactions releases the potential energy, and the energy is then available to do work.

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Photosynthesis is the process by which

plants use the sun’s energy to convert water and carbon dioxide into sugars.

Light is the only source of energy for plants! Plants convert light energy into chemical

energy -> Photosynthesis Recall that light is energy Different colors of light have different

wavelengths and different amounts of energy.

Red light = low energy Blue light = high energy

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR

Light is a form of energy called Electromagnetic energy.

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR A substance’s color is due to chemical

compounds called pigments. When light hits an object the

wavelengths can be transmitted, absorbed, or reflected.

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Chloroplasts contain pigments called

Chlorophyll a, Chlorophyll b, and Carotenoids.

Each pigment absorbs different wavelengths of light.

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Notice that chloroplasts absorb blue-

violet and red-orange light very well. The chloroplasts convert the absorbed

light energy into chemical energy. Why are leaves green? Why do leaves change colors in the fall? Complete Stop & Think #1-4 p. 329

EXPLAIN: CONVERTING SUNLIGHT INTO SUGAR Read “Making Carbon Compounds” p.

330-333 Take notes! Read “Energy Currency of Cells” p. 333 Take Notes.