Name______________KEY______________________ Date_____________ Period_______
Photosynthesis: Making Energy
Chloroplasts
Photosynthesis is a process in which sunlight energy is used to make glucose. The
site of photosynthesis is in the chloroplast – an organelle found in the leaves of
green plants. The main functions of chloroplasts are to produce food (glucose)
during photosynthesis, and to store food energy. Chloroplasts contain the pigment,
chlorophyll. Chlorophyll absorbs most of the colors in the color spectrum, and
reflects only green and yellow wavelengths of light. This is why we see leaves as
green or yellow – because these colors are reflected into our eyes.
1. What is photosynthesis? A process in which sunlight is converted into
glucose.
2. Where does photosynthesis occur? Photosynthesis occurs in the chloroplast.
3. What are chloroplasts and where are they found? An organelle found in the leaves of green
plants.
4. What are the two main functions of chloroplasts? The two functions of a chloroplast are to
produce glucose and store food energy.
5. Why do most leaves appear green? The pigment chlorophyll absorbs red and blue wavelengths
of light and reflects back green and yellow wavelengths of light.
6. What is the primary pigment found in the chloroplast? Chlorophyll is the primary pigment found
in chloroplasts.
Photosynthesis
Glucose is another name for sugar. The molecular formula for glucose is C6H12O6. Plants make sugar by
using the energy from sunlight to transform CO2 from the air with water from the ground into glucose.
This process, called photosynthesis occurs in the chloroplast of the plant cell. During this process,
oxygen (O2) is created as a waste product and is released into the air for us to breath. The formula for
photosynthesis is:
(reactants) (products)
CO2 + H2O + sunlight ----> C6H12O6 + O2
This formula says that carbon dioxide + water molecules are combined with the energy from sunlight to
produce sugar and oxygen. The reactants in photosynthesis (what is used) are CO2, water and sun. The
plant gets water from the ground through its roots. The plant collects carbon dioxide from the air. Much
of the carbon dioxide comes from living organisms that exhale (breath it out) it, but some also comes
from factory smokestacks and car fumes.
7. What is the formula for photosynthesis? CO2 + H2O + sunlight ----> C6H12O6 + O2
8. What three things are used to make glucose in photosynthesis? Carbon Dioxide, water and
sunlight are three things that are used to make glucose in photosynthesis.
