BIOENERGETICS

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BIOENERGETICS
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Bioenergetics

• The study of energy in living systems
  (environments) and the organisms (plants and
  animals) that utilizing them.

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Energy

• Capacity to perform work.
• Two examples
• 1. Kinetic energy
• 2. Potential energy

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Kinetic Energy

• Energy in the process of doing work.
• Energy of motion.
• Examples
• 1. Heat
• 2. Light energy

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Potential Energy

• Energy that matter occupies because of its
  location, arrangement, or position.
• Energy of position.
• Examples
• 1. Water behind a dam
• 2. Chemical energy (gas)

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Thermodynamics

• The study of energy transformations that occur in
  a collection of matter.
• Two Laws
• 1. First Law of Thermodynamics
• 2. Second Law of Thermodynamics

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First Law of Thermodynamics

• Energy cannot be created or destroyed, but only
  converted to other forms.
• This means that the amount of energy in the
  universe is constant.

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Second Law of Thermodynamics

• All energy transformations are inefficient
  because every reaction results in an increase in
  entropy and the loss of usable energy as heat.
• Entropy the amount of disorder in a system.

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Endergonic Reactions

• Chemical reaction that requires a net input of
  energy.
• Example
• 1. Photosynthesis
• 6CO2 6H2O ? C6H12O6 6O2

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Exergonic Reactions

• Chemical reactions that releases energy.
• Example
• 1. Cellular Respiration
• C6H12O6 6O2 ? 6CO2 6H2O

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Cellular Metabolism

• The sum total of the chemical activities of all
  cells.
• Endergonic and Exergonic reactions
• 2 Examples
• 1. Anabolic Pathways
• 2. Catabolic Pathways

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Anabolic Pathway

• Metabolic reactions, which consume energy
  (endergonic), to build complicated molecules from
  simpler compounds.
• Example
• 1. Photosynthesis
• 6CO2 6H2O ? C6H12O6 6O2

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Catabolic Pathway

• Metabolic reactions which release energy
  (exergonic) by breaking down complex molecules in
  simpler compounds.
• Example
• 1. Cellular Respiration
• C6H12O6 6O2 ? 6CO2 6H2O

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Question

• What is ATP?

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Answer

• adenosine triphosphate (ATP)
• Components
• 1. adenine nitrogenous base
• 2. ribose five carbon sugar
• 3. phosphate group chain of three

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Question

• How does ATP work?

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Answer

• Works by the direct chemical transfer of a
  phosphate group.
• This is called phosphorylation.
• The exergonic hydrolysis of ATP is coupled with
  the endergonic processes by transferring a
  phosphate group to another molecule.

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Hydrolysis of ATP

• ATP H2O ? ADP P (exergonic)

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Dehydration of ATP

• ADP P ? ATP H2O (endergonic)

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