Photosynthesis
8.1 Energy of Life
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
Autotrophs and Heterotrophs
• Plants and some other types of
organisms are able to use light
energy from the sun to produce
food.
– Organisms, such as plants, which
make their own food, are called
autotrophs.
– Organisms, such as animals, that
must obtain energy from the
foods they consume are
heterotrophs.
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
Chemical Energy and ATP
• Energy comes in many forms
including light, heat, and
electricity.
• Energy can be stored in chemical
compounds, too.
• An important chemical compound
that cells use to store and release
energy is adenosine
triphosphate, abbreviated ATP.
• ATP is used by all types of cells
as their basic energy source.
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
1
ATP Structure
• ATP consists of:
Ribose
Adenine
3 Phosphate groups
The Nora School
Biology
955 Sligo Avenue
Silver Spring, Maryland 20910
Period ________
Releasing Energy
• Energy stored in ATP is released by
breaking the chemical bond between
the second and third phosphates.
2 Phosphate groups
P
ADP
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
ATP Uses
• The energy from ATP is needed for
many cellular activities, including
– active transport
– protein synthesis
– muscle contraction.
• Most cells have only a small
amount of ATP
• Cells can regenerate ATP from
ADP as needed by using the
energy in foods like glucose.
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
2
Section 8.1 Assessment
1. What is the ultimate source of energy
for plants?
2. What is ATP and what is its role in the
cell?
3. Describe cellular activities that use the
energy released by ATP.
4. How do autotrophs obtain energy?
How doe heterotrophs obtain energy?
The Nora School
955 Sligo Avenue
Silver Spring, Maryland 20910
Biology
Period ________
3