Energy and Matter,

1

• Energy and Matter,
• Their Laws,
• and
• How they are Used in
• Biological Systems

2
Matter is Recycled Through Food Chains.Energy Is
Not Recycled, It Is Transformed.
3
Energy the Capacity to do Work

• Two Basic Forms of Energy
• Kinetic energy is the energy of motion
• Ex. Muscle contractions and relaxation
• Potential energy is stored energy as a result of
  location or structure and can be used in the
  future
• Ex. Top of the hill cyclist

4
Thermodynamics the Study of Energy
Transformations

• Two Laws of Thermodynamics
• Law of Conservation of Matter
• Energy can neither be created nor destroyed, it
  must be transformed from one form to another
• Law of Entropy
• At every transformation of energy from one form
  to another some energy is converted to heat and
  lost.

5
Metabolism Energy Transformations in Cells

• The food we eat has chemical bond energy, which
  is converted
• into ATP bond energy, then it may be used for the
  metabolic
• work of the cell. Some energy is always lost as
  Entropy (heat).

6
Metabolism Has Two Types of Chemical Reactions

• Catabolic Reactions
• Break down of large molecules (polymers) into
  smaller subunits
• Products have less energy than reactants
• Energy is released, which is converted into ATP,
  the energy currency of cells
• ATP energy may be used for cellular work
• EXERGONIC

• Anabolic Reactions
• Building of large molecules from smaller subunits
• Products have more energy than the reactants
• Energy is consumed during the reaction, usually
  provided by ATP
• ENDERGONIC

7
Endergonic Reactions are Chemical Reactions
that Consume and Store Energy
8
Exergonic ReactionsChemical Reactions that
Release Energy

9
ATP and Energy Coupling

• Energy released from exergonic reactions is
  converted into ATP (phosphate bond) energy and
  used for powering endergonic reactions in the
  cell.

10
Adenosine Tri Phosphate isthe Energy Currency in
Cells
11
The Sun is the Ultimate Energy Source, which
Maintains Life on the Surface of the Earth

• Almost all of the chemical energy used by
  organisms ultimately comes from the sun.
• Organic matter is recycled through
  producer/consumer relationships in food webs.