Import

• What do living cells require to perform tasks?

  Energy from outside sources
• How does energy enter and leave ecosystems?

  Enters as sunlight, leaves as heat
• What does photosynthesis generate for cellular respiration?

  Oxygen and organic molecules
• What is the primary function of ATP in cells?

  Drives most cellular work
• What are the three key pathways of respiration?

  Glycolysis, citric acid cycle, oxidative phosphorylation
• What is fermentation in relation to glycolysis?

  A simpler pathway coupled to glycolysis
• What do catabolic pathways do to organic fuels?

  Yield energy by oxidizing them
• What role does electron transfer play in catabolic pathways?

  It plays a major role
• Why do organic compounds possess potential energy?

  Due to the arrangement of electrons in bonds
• What do enzymes do in catabolic pathways?

  Catalyze the degradation of organic molecules
• What happens to some of the energy released in catabolic pathways?

  It is used to do work; the rest is heat
• What is fermentation's relationship with oxygen?

  It leads to partial degradation without oxygen
• What is aerobic respiration?

  A process that consumes oxygen to break down molecules
• Which organisms can carry out aerobic respiration?

  Most eukaryotic and many prokaryotic organisms
• What is anaerobic respiration?

  A process using compounds other than oxygen
• How is cellular respiration commonly referred to?

  Usually refers to aerobic processes
• How is aerobic respiration similar to combustion?

  Both involve fuel and produce CO2 and water
• What is the overall catabolic process equation?

  Organic compounds + O2 → CO2 + H2O + energy
• What is the specific equation for glucose catabolism?

  C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
• What is the energy change for glucose catabolism?

  ΔG = −686 kcal per mole of glucose
• What happens to some of the energy released during glucose catabolism?

  It is used to produce ATP
• What do redox reactions release energy from?

  When electrons move closer to electronegative atoms
• What are oxidation-reduction reactions?

  Reactions transferring electrons from one reactant to another
• What is oxidation in redox reactions?

  The loss of electrons from a substance
• What is reduction in redox reactions?

  The addition of electrons to another substance
• Why is adding electrons called reduction?

  It reduces the positive charge of the atom
• In the reaction Na + Cl → Na+ + Cl−, what happens to sodium?

  Sodium is oxidized
• In the reaction Na + Cl → Na+ + Cl−, what happens to chlorine?

  Chlorine is reduced
• What is the general form of a redox reaction?

  Xe− + Y → X + Ye−
• What is the role of the reducing agent in a redox reaction?

  It donates electrons to another substance
• What is the role of the oxidizing agent in a redox reaction?

  It accepts electrons from another substance
• What do redox reactions require?

  Both a donor and an acceptor
• When do redox reactions occur without complete electron transfer?

  When there is a change in electron sharing
• What happens to covalent bonds in the combustion of methane?

  Nonpolar bonds convert to polar covalent bonds
• What happens to electrons in methane combustion?

  They end up closer to electronegative oxygen
• What is the effect of oxygen's electronegativity in reactions?

  It draws electrons closer, reducing them
• What must be added to pull an electron away from an atom?

  Energy
• What happens to an electron's potential energy when it shifts to a more electronegative atom?

  It loses potential energy
• What type of redox reaction releases chemical energy?

  One that relocates electrons closer to oxygen
• What is respiration in terms of glucose oxidation?

  An oxidation process that is a redox process