1.How do plants get

energy?

2. How do animals get energy ?

CATALYST

2.WHY DO LEAVES Why do leaves chang change color in the f fall?

Essential Question

Objectives: I CAN…

□Relate the structure of a chloroplast to the events in photosynthesis

PHOTOSYNTHESIS

• Photosynthesis Process that uses the sun’s energy to make simple sugars

Take Notes!Topic: Photosynthesis

The general equation for photosynthesis is written as:

6CO2 + 6H2O→C6H12O6 + 6O2

Carbon Dioxide + Water Glucose + Oxygen

• Photosynthesis Equation

6CO2 + 6H2O→C6H12O6 + 6O2

Take Notes!Topic: Photosynthesis

Read:• The chloroplast is the part of the plant’s leaf

where photosynthesis takes place. The chloroplast contains pigments, which are molecules that take in specific wavelengths of sunlight. Wavelengths of sunlight transfer energy. The most common pigment in the chloroplast is chlorophyll. Chlorophyll is a plant pigment that absorbs most wavelengths of sunlight except green. Because it cannot take in the green wavelength, it reflects the green. This is what makes leaves look green. In the fall, leaves stop producing chlorophyll, so other pigments become visible. This gives leaves a wide variety of colors.

1. Where does photosynthesis take place?

Chloroplast in plant cells2. What is the purpose of pigment?

Molecules that take in specific wavelengths of sunlight

3. What is the most common pigment in plants?

Chlorophyll4. Why do leaves change color in the fall?

Plants stop producing chlorophyll so other pigments become visible

To trap the energy in the sun’s light, the thylakoid membranes contain pigments, molecules that absorb specific wavelengths of sunlight.

Chloroplasts contain several kinds of pigments, the most common is chlorophyll.

• Pigments • molecules that absorb specific wavelengths of sunlight

• Chlorophyll most common in leaves

Take Notes!Topic: Photosynthesis

WHY ARE PLANTS GREEN?Chlorophyll absorbs most wavelengths of light except green. Chlorophyll reflects the green, so that’s what you see!

• Two STAGES of Photosynthesis

1. The light-dependent reactions convert light energy into chemical energy (ATP)

2. ATP fuels the light-independent reactions that produce simple sugars.

Take Notes!Topic: Photosynthesis

The following table shows how much of each pigment is present within a leaf during different months. Use the information to answer the questions that follow.

PigmentMay June July August Septem

berOctobe

r

Chlorophyll

2.92 2.95 3.37 3.15 1.58 0.6

Xanthophyll

1.12 1.05 0.89 0.82 1.17 1.32

Carotene 2.32 2.25 2.22 2.20 2.62 2.88

1. During which months is the amount of Carotene in a leaf greater than the amount of Chlorophyll? 2. Looking at the table, what months will all of the leaves be green?

WHY DO LEAVES CHANGE COLOR IN THE FALL?