1. Energy and Life
Chapter 8.1

2. Chemical Energy and ATP
Energy is the ability to do work.
Cells are constantly using energy to perform LIFE FUNCTIONS.
Metabolism
Homeostasis
Reproduction
Transport

3. Chemical Energy and ATP
Energy comes in many forms:
Light
Heat
Sound
Electricity
Without ENERGY, life would not exist.
Living things use CHEMICAL FUEL (ATP).
ATP is the MOST important chemical fuel for cells.

4. Chemical Energy and ATP
The chemical compound that cells use to store and release ENERGY is ADENOSINE TRIPHOSPHATE or ATP.
ATP is a type of NUCLEIC ACID
ATP has 3 parts:
ADENINE
a 5-CARBON SUGAR called RIBOSE
THREE phosphate groups.
The three phosphate groups are the KEY to ATP’s ability to STORE and RELEASE energy.

5. ATP

6. adenosine TRI phosphate
ADP vs. ATP
adenosine DI phosphate
adenosine TRI phosphate
Di = 2
Tri = 3

7. Storing Energy: ADP to ATP
ADP is a compound that looks like ATP except it has 2 PHOSPHATE GROUPS instead of 3 PHOSPHATE GROUPS.
Organisms STORE energy by adding a PHOSPHATE to ADP and the energy is stored in the BOND between the last 2 PHOSPHATES.
ADP is like a RECHARGEABLE BATTERY.

8. Releasing Energy ATP to ADP
Cells can release the ENERGY stored in the ATP by breaking the BOND that holds PHOSPHATE #2 and PHOSPHATE #3.
This is an efficient way of STORING and RELEASING energy as the CELL needs it.
Why do cells need energy?

9. Where do living things get ATP from?
HETEROTROPHS
AUTOTROPHS
Consume OTHER LIVING THINGS for energy.
Classifications
HERBIVORES eat only plants.
OMNIVORES eat plants and animals.
CARNIVORES eat only animals.
Can make their own energy directly from the sun through PHOTOSYNTHESIS.
Classifications
Plants
Algae
Some bacteria