Name: ___________________________________________ Period: _________ Date: ________
Chapter 3.3 Reading Guide: Photosynthesis
Sources of Energy
1. In the process of photosynthesis, plants use energy from the _____________________ to make food.
2. Almost all living things get energy, either directly or indirectly, from the energy of the ________________________.
3. During ____________________________ that energy from the sun is captured.
4. Complete the following table about how living things use the sun’s energy. Figure 13 can help you learn.
How Living Things Use Energy From the Sun
Living Thing
Gets energy from the sun directly or indirectly?
Autotroph or Heterotroph?
Grass
Zebra
Lion
5. Photosynthesis comes from Greek words. Photosynthesis can be broken up into two parts: PHOTO and
SYNTHESIS
What does PHOTO mean? ___________________________________________________________________________
What does SYNTHESIS mean? _______________________________________________________________________
6. What is PHOTOSYNTHESIS? ______________________________________________________________________
___________________________________________________________________________________________________
The Two Stages of Photosynthesis
7. List the two stages in the process of photosynthesis.
a. ___________________________________________________________________
b. ___________________________________________________________________
8. In the first stage of photosynthesis, the green pigment in chloroplasts, called ____________________________, absorbs light
energy from the sun.
9. During the second stage of photosynthesis, the energy captured by the sun is used to make _________________.
10. Besides the energy in sunlight, the cell needs ___________________ and ________________________ to make sugar.
The Photosynthesis Equation
11. Write the chemical equation for photosynthesis that is under the title for this section.
____________________ + ____________________
_______________________ + _____________
12. The arrow can be read as ‘yields’. What does the word yield mean in this context?
_______________________________________________________________________________
13. Reactants are also called raw materials or starting materials. What are the reactants for photosynthesis?
___________________________and ________________________and _______________________
14. Products are what you end up with after the reaction has occurred. What are the products of photosynthesis?
___________________________and ________________________
Name: ___________________________________________ Period: _________ Date: ________
15. Sugar is a compound made from the elements carbon, hydrogen and oxygen. What substance(s) did the atoms
that the plant uses to make sugar come from?
Example: Carbon comes from ______carbon dioxide___________________
Hydrogen comes from _____________________________________
Oxygen comes from ______________________________________
16. Plants need several ingredients (reactants) for photosynthesis. Where do each of the ingredients come from?
Example: Carbon dioxide moves into plant leaves from the air by entering through the _____stomata_______.
Water enters the plant through the _________________________________.
Energy from sunlight is absorbed by the ______________________________________ (organelle) which are
located in the plant’s leaves.
17. What happens to the products of photosynthesis?
Example: Some oxygen leaves the plant by exiting through the _______stomata________ in the leaves. Some
oxygen is kept in the plant and used for a different chemical reaction.
Some of the sugar (glucose) is used for _____________________________, some sugar is converted into
another molecule called __________________________, and some sugar is stored by the plant for later use.
18. In the space below, draw a picture that shows the process photosynthesis. Your picture should include a
plant. Your picture should also include each of the 3 ingredients (water, carbon dioxide, energy from sunlight) and
2 products (glucose and oxygen) of photosynthesis.