12.1 Food and Fuel Pathways of Metabolism

• Autotrophs vs Heterotrophs:

  • Autotrophs: Produce their own food (e.g., plants).

  • Heterotrophs: Obtain food from other sources (e.g., animals).

• Monomers and Polymers:

  • Identify the monomer and polymer forms for major metabolic fuels.

• Storage Forms:

  • Glucose: Stored as glycogen.

  • Fats: Stored as triglycerides.

  • Proteins: Not stored; mobilized in starvation.

12.2 Metabolic Pathways Common Features

• Chemical Features of Metabolic Pathways:

  • Recognize chemical features of metabolic pathways.

• Redox Partners:

  • Identify oxidized/reduced partners in reactions.

• Role of Cofactors:

  • Describe cofactors and coenzymes in redox reactions.

  • Common coenzymes: NAD+/NADH, FAD/FADH2, ubiquinone.

• Connection of Pathways:

  • Metabolic pathways are connected, regulated, and cell-specific.

• Vitamin Differences:

  • Contrast fat- and water-soluble vitamins; know dangers of fat-soluble vitamins.

12.3 Free Energy Changes in Metabolic Reactions

• Energy Changes:

  • Analyze changes during metabolic reactions.

• Free Energy Change:

  • Distinguish between actual and standard free energy change.

  • Relate free energy changes to reactant concentrations.

• Reaction Coupling:

  • Explain coupling of reactions and its benefits.

• Energy Currency:

  • Identify molecules that function as energy currency.

• Pathway Control:

  • Explain how certain reactions control flux in a pathway.

13.1 Glycolysis

• Glycolysis Overview:

  • Describe substrates, products, coenzymes, and enzymes in glycolysis.

  • Identify energy-consuming and generating steps.

  • List flux-control points.

• Pyruvate Metabolism:

  • Describe metabolic uses of pyruvate and activation conditions.

13.2 Gluconeogenesis

• Gluconeogenesis Details:

  • Substrates, products, coenzymes, and enzymes involved.

  • Unique enzymes of gluconeogenesis vs. glycolysis.

• Homeostasis:

  • Explain the relationship between rates of gluconeogenesis and glycolysis.

13.3 Glycogen Synthesis and Degradation

• Comparative Processes:

  • Compare glycogen synthesis and degradation.

• Substrates and Products:

  • Identify substrates and products for both pathways.

• Energy Needs:

  • Compare energy requirements of each process.

• Fates of Glucose-6-Phosphate:

  • List metabolic fates.

13.4 The Pentose Phosphate Pathway

• Pathway Overview:

  • Describe substrates, products, coenzymes, and enzymes involved.

• Oxidation-Reduction Reactions:

  • Identify redox reactions in the pathway.

• Ribose Groups Need:

  • Explain pathway response to ribose group needs and its role in glucose metabolism.

13.5 Clinical Connection: Disorders of Carbohydrate Metabolism

• Enzyme Deficiencies:

  • Relate to defects in carbohydrate metabolism.

• Glycogen Storage Diseases:

  • Describe symptoms affecting liver and muscle.

• Hormone Signaling Effects:

  • Summarize effects of insulin, epinephrine, and glucagon on fuel metabolism and starvation changes.

14.1 The Pyruvate Dehydrogenase Reaction

• Reaction Summary:

  • Summarize reactions by pyruvate dehydrogenase complex.

• Substrates, Products, and Cofactors:

  • List key components and advantages of the multienzyme complex.

14.2 The Eight Reactions of the Citric Acid Cycle

• Cycle Overview:

  • Describe substrate, product, coenzymes, enzymes, and reactions.

• Carbohydrate Metabolism Connection:

  • Explain how the cycle fits into broader carbohydrate metabolism.

14.3 Thermodynamics of the Citric Acid Cycle

• Energy Recovery:

  • Explain energy recovery for the cell.

• ATP Yield Calculation:

  • Calculate ATP yield for one cycle round.

• Regulation Points:

  • Identify irreversible steps regulating flux.

• Reversible Reactions:

  • Describe how cycle reactions may function in reverse.

14.4 Anabolic and Catabolic Functions of the Citric Acid Cycle

• Metabolic Connection:

  • Explain connection with amino acid and fatty acid metabolism.

• Cycle Intermediates:

  • Identify intermediates as precursors for other compounds.

• Intermediate Replenishment:

  • Describe replenishment of citric acid cycle intermediates.