SECTION 8.1

Transformation of Energy

  • energy is the ability to do work
  • thermodynamics is the study of the flow and transformation of energy

Laws of Thermodynamics
  • First law-energy can be converted from one form to another,but it cannot be created nor destroyed
  • Second law-energy cannot be converted without the loss of usable energy (heat,friction,sound,light,etc.)
Metabolism
  • All of the chemical reactions in a cell
  • Photosynthesis- light energy from the sun is converted to chemical energy(glucose) for use by the cell
  • Cellular respiration- organic molecules are broken down to release energy for use by the cell

ATP: The Unit of Cellular Energy
  • ATP- the energy currency of the cell, Adenosine Triphosphate
  • ATP stores and releases a small amount of energy for movement, transport and other active processes in the cell.
  • Both heterotrophs and autotrophs use ATP as an energy storage molecule in their cells.
  • ATP is used to power processes in the cell such as the Calvin cycle of photosynthesis in which CO2 is converted into glucose.
  • ATP is also used for movement within the cell.
  • It is produced during cell respiration when carbohydrates such as glucose are broken down.
  • Energy is released when the third phosphate on ATP is removed and transferred to another molecule.
  • This leaves behind ADP (adrenosine diphosphate).