Respiration

• Respiratory Substrates


  Molecules that are used to produce ATP in a living cell
• Glucose


  A type of carbohydrate that is a respiratory substrate with an energy value of 16 kJ/g
• Lipid


  A type of fat that is a respiratory substrate with an energy value of 39 kJ/g
• Protein


  A macromolecule composed of amino acids that is a respiratory substrate with an energy value of 17 kJ/g
• Fatty acids


  Components of lipids that are broken down into two Acetyl CoA molecules and enter the Krebs cycle as respiratory substrates
• Amino acids

  The building blocks of proteins that are deaminated and converted into pyruvate or acetate to enter the Krebs cycle as respiratory substrates
• Glycogen


  A polysaccharide that is hydrolyzed to produce glucose as a respiratory substrate
• Starch


  A polysaccharide that is hydrolyzed to produce glucose as a respiratory substrate
• Pyruvate


  A molecule produced from the hydrolysis of protein that serves as a respiratory substrate
• Acetyl CoA


  A molecule that enters the Krebs cycle as a respiratory substrate
• Krebs Cycle


  A metabolic pathway where Acetyl CoA is used as a respiratory substrate
• Energy values of respiratory substrates

  The energy value of a respiratory substrate is determined by the number of hydrogens in the molecule
• Respiratory Quotient (RQ)


  The ratio of oxygen absorbed to carbon dioxide given off in respiration
• Calculating RQ


  RQ can be calculated by dividing the volume of carbon dioxide given off by the volume of oxygen taken in
• Aerobic Respiration


  The process of respiration that uses oxygen as a respiratory substrate
• Anaerobic Respiration


  The process of respiration that occurs without the use of oxygen as a respiratory substrate
• Respirometer


  An apparatus used to measure oxygen consumption and carbon dioxide production
• Sodium Hydroxide


  A substance used in a respirometer to absorb carbon dioxide
• Measuring Respiratory Quotient


  The respiratory quotient (RQ) can be calculated using the formula RQ = x + y or RQ = x - z, where x represents oxygen consumption, y represents the increase in air volume, and z represents the decrease in air volume
• Anaerobic Respiration


  Metabolic pathway that occurs when free oxygen is not available, resulting in a lower yield of ATP compared to aerobic respiration.
• NADred


  Reduced form of NAD (Nicotinamide adenine dinucleotide) that cannot be recycled to NAD in anaerobic respiration.
• Cytoplasm


  Location where anaerobic respiration occurs, as the stages of respiration inside the mitochondrion cannot take place.
• Link Reaction


  Process where pyruvate passes into the mitochondrion, but does not occur in anaerobic respiration.
• Krebs Cycle


  Process that does not occur in anaerobic respiration, where pyruvate is further broken down inside the mitochondrion.
• Oxidative Phosphorylation


  Process that does not occur in anaerobic respiration, where ATP is produced using energy from the electron transport chain.
• Alcoholic Fermentation


  Pathway in anaerobic respiration where pyruvate is converted to ethanol, regenerating NAD.
• Ethanal


  Intermediate compound formed during alcoholic fermentation when pyruvate is decarboxylated.
• Lactate Fermentation


  Pathway in anaerobic respiration where pyruvate is converted to lactate, regenerating NAD.
• Cori Cycle


  Process in the mammalian liver that reverses lactate fermentation, converting lactate back to pyruvate.
• Glycolysis


  Process that continues in anaerobic respiration, providing a net gain of ATP.
• Temporary Measure

  Anaerobic respiration is a temporary measure when oxygen is limited.
• Electron Transport Chain

  The final stage of aerobic respiration where energy is released to allow phosphorylation of ADP.
• Oxidative Phosphorylation


  The process in the electron transport chain that uses oxygen, reduced NAD and FAD, and electron carriers to produce ATP.
• Cytochrome

  An electron carrier protein in the electron transport chain.
• NADH


  Reduced NAD, a molecule that carries hydrogen atoms in the electron transport chain.
• FADH2


  Reduced FAD, a molecule that carries hydrogen atoms in the electron transport chain.
• Proton


  A positively charged particle formed when hydrogen atoms are split into protons and electrons.
• ATP Synthase


  An enzyme that synthesizes ATP using the energy from the movement of protons across a membrane.
• Proton Motive Force

  The energy stored in the form of a proton gradient across a membrane, used by ATP synthase to produce ATP.
• Glycolysis


  The process of breaking down glucose into pyruvate in the cytoplasm.