Religion

Chapter 8: Photosynthesis
8.1 Energy of Life (p. 201)
I.   Autotrophs and Heterotrophs
A. Plants and some other types of organisms are able to use light energy from the sun to produce food.
  B. Energy is essential to life; all living organisms must be able to obtain energy from the environment.
C.   Plants are able to trap light energy and use it.
1. Autotrophs = organisms such as plants that are able to make their own food
  D. Other organisms must eat food to obtain energy.
1. Heterotrophs = organisms such as animals that must obtain energy from their food.

II.   Chemical Energy and ATP
A. Work and the need for energy. (Fig 8-3)
  1. Many cellular processes require energy.
Ex.   Active transport, cell division, locomotion of cell, are some
examples.
  2. ATP (adenosine triphosphate) is a molecule in your cells that is the source of energy.
  3. This energy is stored in the chemical bonds of ATP.
  4. ATP is composed of:
      a. one adenosine molecule   (which is the sugar ribose connected to an adenine molecule)
      b. three phosphate groups
III. Forming and Breaking Down ATP
  1. The energy of ATP becomes available to a cell when the molecule is broken down.
  2. When ATP is broken down energy is released and the resulting molecule is ADP (adenosine diphosphate)
  3. ATP is broken down into ADP when the chemical bond between the second and third phosphate group in ATP is broken.
  4. At this point ADP can form ATP again by bonding with another phosphate group.
  5. This process creates a renewable cycle. (fig. 8-3)
*As long as phosphate groups are available, a cell can create
  ATP whenever it needs to.
A. How cells tap into the energy stored in ATP?
  1. When ATP is broken down and the energy is released, it must be captured and used or it is wasted and given off as heat.
  2. ATP     ADP   +   P   +   Energy
  3. To access the energy locked up inside an ATP molecule it usually binds to a protein (or enzyme)....