CONCEPT 7. Energy

• Name different forms of energy in biological systems

  Chemical bonds, electrical energy, heat energy, light energy, mechanical energy
• What are the two types of energy?

  Potential energy and kinetic energy.
• How does ATP store energy?

  Captures free energy, storing it in its final oxygen phosphate bond
• What is the product of hydrolysis of ATP?

  ADP + Pi
• What type of reaction is hydrolysis of ATP?

  Exergonic, as energy is released
• What occurs in oxidation?

  Electrons are lost e.g NADH -> NAD+
• What occurs in reduction?

  Electrons are gained e.g NAD+ -> NADH
• What is an exergonic reaction?

  An exergonic reaction is a chemical reaction that releases energy.
• What is a catabolic reaction?

  A catabolic reaction is a metabolic process that breaks down larger molecules into smaller ones, releasing energy in the process.
• What is an endergonic reaction?

  An endergonic reaction is a chemical reaction that requires an input of energy.
• What is an anabolic reaction?

  An anabolic reaction is a metabolic process in which smaller molecules are combined to form larger molecules, requiring energy.
• What is free energy?

  The energy available to do work.
• The more G (free energy), the more instability and tendency to change to a stable state.
• What are spontaneous reactions?

  Reactions that do not require an input of energy, also known as exergonic reactions
• What is activation energy?

  Activation energy is the minimum amount of energy required for a chemical reaction to occur. This energy transitions the reactants out of their stable state and into a transition state.
• What is the role of enzymes?

  Lower the energy barrier required for a reaction to take place by creating a more unstable environment for the reactants
• What is the equilibrium point?

  The point at which products are in their most stable state
• What are examples of endergonic and exergonic reactions?

  Endergonic: Photosynthesis Exergonic: Cellular respiration
• What are examples of electron carriers?

  NADH and FADH2
• How does NAD+ become converted into NADH?

  Reduction
• How does NADH become converted in NAD+?

  Oxidation
• How does FAD become converted into FADH2?

  Reduction
• How does FADH2 become converted into FAD?

  Oxidation
• What are redox reactions?

  Redox reactions are chemical reactions that involve the transfer of electrons between species.
• What is the role of electron carriers?

  To transport electrons during metabolic processes.
• In what ways can enzymes affect a substrate?

  • Orientation: two substrates are orientated so they can react
  • Physical strain: enzyme strains the substrate
  • Chemical charge: enzyme adds charges to the substrate