1. 8.1 Energy and Life
Biology

2. I. Autotrophs and Heterotrophs
Energy is the ability to do work
Need to use and obtain energy or living things will die
Energy comes from food or sun
Autotrophs
Use light energy to make their own food
Plants, some bacteria

3. Heterotrophs Organisms that cannot make their own food
Eat food to get energy
Example: us, leopards, etc
Can also be decomposers
Ex: mushrooms, fungi

4. II. Chemical energy and ATP
Energy has many forms like heat, light, electricity
Also in the form of chemical compounds
To release energy from chemical compounds, bonds are broken that hold the elements together
ATP (adenosine triphosphate)
Cellular energy
Made of adenine (sugar), ribose (sugar), and 3 phosphates

5. Storing energy ADP (adenosine diphosphate) only 2 phosphates attached
When a cell has energy, it can store it by adding a 3rd phosphate to make ATP

6. Releasing Energy
To release energy in ATP, the last bond that holds the 3rd phosphate is broken
Energy is released

7. III. Using biochemical energy
Uses of ATP
Active transport
Making proteins and nucleic acids
Produce light (firefly)
Cell only keeps a small amount of ATP on hand
Its more efficient
Make more energy by using the food we take in
Cellular energy is created in the mitochondria

8. Photosynthesis Equation
Carbon dioxide + water + light
glucose (C6H12O6) + oxygen

9. Light and Pigments Plants use sun’s energy to go thru photosynthesis
Pigments in plants help to absorb light
Pigment-light absorbing molecule
Main pigment
chlorophyll

10. Lights and Pigments The color you see is reflected
Chlorophyll reflects green light and absorbs reds and blues very well
Other pigments are present
Xanthophylls (reflect yellow) and carotene (orange)