MP 4.1 - Midterms

• Metabolism


  The sum of all chemical processes that occur within a cell
• Catabolism (Catabolic)


  Breakdown of complex organic molecules into simpler compounds. It releases energy.
• Anabolism (Anabolic)


  Building of complex organic molecules from simpler ones. It requires energy.
• Enzymes


  A special group of protein molecules that bring about a chemical change while themselves remaining unchanged
• Function of Enzymes

  • They speed up chemical reactions and lower the activation energy required for biological reactions to occur
• Substrate


  Substance acted upon by enzymes
• End Products


  Products of enzyme reactions
• Types of Enzymes


  • Hydrolases
  • Oxidases
  • Transferases
  • Oxidoreductases
  • Hydrolases
  • Ligases
• Linking Enzyme


  An enzyme that joins two molecules, especially in living organisms
• Apoenzyme


  Protein portion
• Coenzyme (Cofactor)


  Non-protein part; often metal ions
• Holoenzyme


  Whole enzyme; formed together by the apoenzyme and cofactor
• Coenzyme


  Organic molecules that act as electron carriers in metabolic reactions
• Competitive Inhibition


  Inhibitor "looks like" the natural substrate and fills the active site preventing the enzymatic reaction
• Competitive Inhibition


  • Penicillin
  • Sulfanilamide (Sulfa Drugs)
• PABA


  Colorless acid used in sunscreens
• Folic Acid


  Required for the synthesis of DNA and RNA
• Pentaglycine-5 AA


  Found in proteins, inhibits the transmission of nerve impulses in cells
• Noncompetitive Inhibition


  Inhibitor binds to another site on the enzyme (Allosteric Site) and causes a change in the active site and loss of activity
• Adenosine Triphosphate (ATP)


  A molecule found in all living organisms that is the main immediate source of usable energy for the activities of the cells
• ATP


  A highly energy yielding compound which supplements enzymes in the biochemical reactions of metabolism
• How to Make ATP

  ADP + Phosphate + Energy = ATP
• Phosphorylation


  Adding the phosphate to ADP to make ATP
• Substrate Level Phosphorylation


  The phosphate is transferred directly to the ADP to make ATP
• Oxidative Phosphorylation


  Electron carriers such as NAD+ transfer electrons to a series of carriers in the electron transport chain where energy is released and transferred to ADP to make ATP
• Carbohydrate Catabolism


  Microorganisms oxidize carbohydrates as their primary source of energy
• Glucose


  Most common energy source
• Energy obtained from glucose by


  • Respiration
  • Fermentation
• Cellular Respiration


  Cells use oxygen to break down glucose and store its energy in molecules of ATP
• Critical Ingredients for Cellular Respiration


  Glucose and Oxygen
• Anaerobic Respiration


  Production of energy without oxygen
• 2 Stages of Fermentation

  1. Glycolysis

  2. Recycling Stage
• Glycolysis in Fermentation


  The only stage of fermentation that yields ATP, and while it produces a relatively small amount, it is ample for simple cells
• Recycling Stage of Fermentation


  NADH produced in glycolysis is recycled back into NAD+ to be used again in glycolysis
• Types of Fermentation


  • Lactic Acid Fermentation
  • Alcohol Fermentation
  • Propionic Acid Fermentation
• Aerobic Respiration


  Electrons released by oxidation are passed down an Electron Transport System with oxygen being the Final Electron Acceptor
• General Equation: Glucose + Oxygen → Carbon dioxide + Water = ATP
• Glycolysis


  Glucose molecules are broken down to form pyruvic acid molecules
• Krebs Cycle


  Pyruvic acid is further broken down and the energy in its molecule is used to form high-energy compounds such as NADH
• Electron Transport System


  Electrons are transported along a series of coenzymes and cytochromes and the energy in the electrons is released. It produces 34 ATP.