1. Chapter 8-1: Energy & Life

2. Autotrophs and Heterotrophs (a review)
all energy comes from the sun
Organisms get their energy in two ways
autotrophs: plants and other organisms that can make their own food
heterotrophs: organisms that obtain energy by consuming other organisms

3. Autotrophs Sunlight is the main energy source for life on Earth.
Some organisms rely on energy stored in inorganic chemical compounds…
Water can be loaded with chemical energy!
Autotrophs: organisms that can make their own food.
Ex: plants! They use sunlight, water and CO2 to make energy and oxygen…
PHOTOSYNTHESIS

4. Heterotrophs Types of consumers/heterotrophs
Herbivores: obtain energy by eating plants.
Carnivores: obtain energy by eating animals.
Omnivores: obtain energy by eating plants and animals.
Detritivores: obtain energy by feeding on plant/animal remains or other dead matter.
Decomposers: organisms that break down organic matter for energy.
Ex: some bacteria and fungi

5. Chemical Energy and ATP
three types of energy (heat, light, and chemical)
Food stores a lot of the chemical energy
Food is not an usable form of chemical energy in cells
It must be converted to a usable form
Food is changed into:
adenosine triphosphate (ATP): chemical fuel that powers cell’s activities

6. ATP: Adenosine Triphosphate

7. ATP is converted to ADP when terminal phosphate bond is broken and energy is released
ADP = Adenosine Diphosphate (2 phosphates instead of 3)
ADP is converted to ATP when a high energy phosphate is added (energy is stored)
ATP ADP + P

8. releasing energy from ATP
the energy released from ATP is used to power a variety of cellular activities
using biochemical energy
powers active transport
powers the sodium-potassium pump
powers movement of organelles within the cell

9. ATP and Glucose (sugar)
cells only store small amounts of ATP (inefficient for storing energy)
energy from carbohydrates used to regenerate ATP from ADP as needed

10. Chapter 8 Study Guide
Complete questions 5 – 22
Due tomorrow!