Cellular Respiration

• Metabolism: All chemical reactions taking place in an organism
• Metabolic Pathway: A particular sequence of connected reactions
• Enzyme: A protein that facilitates a specific chemical reaction
• ATP (adenosine triphosphate): A high-energy molecule used to provide energy in cells
• ADP (adenosine diphosphate): The lower-energy form of ATP
• NADH, FADH2, NADPH: High-energy molecules carrying high-energy electrons
• NAD+, FAD+, NADP+: Lower-energy forms of the above molecules without high-energy electrons
• Glycolysis: A metabolic pathway that breaks down glucose into two molecules of pyruvate
• The Citric Acid Cycle (AKA Krebs Cycle or Tricarboxylic Acid Cycle): A cyclical metabolic pathway that breaks down pyruvate into 3 CO2
• Oxidative Phosphorylation: A chain of molecules uses energy from NADH and FADH2 to generate a H+ gradient
• Fermentation: A metabolic pathway that changes pyruvate; only used in the absence of oxygen.