Biology Chapter 5

  1. Energy
    The capacity to do work
  2. Entropy
    Measure of how much the energy of a system is dispersed
  3. First Law of Thermodynamics
    Energy cannot be created or destroyed
  4. Kinetic Energy
    The energy of motion
  5. Potential Energy
    Stored Energy
  6. Second Law of Thermodynamics
    Energy tends to disperse spontaneously
  7. Activation Energy
    Minimum amount of energy required to start a reaction
  8. Endergonic
    Describes a reaction that requires a net input of free energy to proceed
  9. Exergonic
    Describes a reaction that ends with a net release of free energy
  10. Product
    A molecule that remains at the end of a reaction
  11. Reactant
    A molecule that enters a reaction
  12. Active Site
    Of an enzyme, pocket in which substrates bind and a reaction occurs
  13. Catalysis
    The acceleration of a reaction by a molecule that is unchanged by participating in the reaction
  14. Induced-Fit Model
    The concept that substrate binding to an active site of an enzyme improves the fit between the two molecules
  15. Substrate
    A molecule that is specifically acted upon by an enzyme
  16. Transition State
    Point during a reaction at which substrate bonds reach their breaking point and the reaction will run spontaneously
  17. Allosteric
    Describes a region of an enzyme that can bind a regulatory molecule and is not the active site
  18. Electron Transfer Chain
    Array of enzymes and other molecules that accept and give up electrons in sequence, thus releasing the energy of the electrons in usable increments
  19. Feedback Inhibition
    Mechanism in which a change that results from some activity decreases or stops the activity
  20. Metabolic Pathway
    Series of enzyme-mediated reactions by which cells build, remodel, or break down an organic molecule
  21. Redox Reaction
    Oxidation-reduction reaction, in which one molecule accepts electrons (it becomes reduced) from another molecule (which becomes oxidized)
  22. Antioxidant
    Substance that prevents oxidation of other molecules
  23. ATP
    The nucleotide adenosine triphosphate
  24. ATP/ADP cycle
    Process by which cells regenerate ATP. ADP forms when ATP loses a phosphate group, then ATP forms again as ADP gains a phosphate group
  25. Coenzyme
    An organic molecule that is a cofactor
  26. Cofactor
    A metal ion or a coenzyme that associates with an enzyme and is necessary for its function
  27. Phosphorylation
    Transfer of a phosphate group from one molecule to another
  28. Metal Ions
    • Iron
    • Magnesium
    • Manganese
    • Zinc
    • Selenium
    • Copper
  29. Coenzymes
    • NADH, NAD+
    • FAD, FADH, FADH2
    • CoA
    • Heme
    • Ascorbic Acid
    • Biotin
  30. Adhesion Protein
    Membrane protein that helps cells stick together in animal tissues
  31. Fluid Mosaic
    Model of a cell membrane as a two-dimensional fluid or mixed composition
  32. Receptor Protein
    Plasma membrane protein that binds to a particular substance outside of the cell
  33. Recognition Protein
    Plasma membrane protein that identifies a cell as belonging to self (one's own body)
  34. Transport Protein
    Protein that passively or actively assists specific ions or molecules across a memrane
  35. Concentration
    Number of molecules or ions per unit volume
  36. Concentration gradient
    Difference in concentration between adjoining regions of fluid
  37. Diffusion
    Spontaneous spreading of molecules or ions in a liquid or gas
  38. Hypertonic
    Describes a fluid that has a high overall solute concentration relative to another fluid
  39. Hypotonic
    Describes a fluid that has a low overall solute concentration relative to another field
  40. Isotonic
    Describes two fluids with identical solute concentrations
  41. Osmosis
    The diffusion of water across a selectively permeable membrane in response to a concentration gradient
  42. Osmotic Pressure
    Amount of turgor that prevents osmosis into cytoplasm or other hypertonic fluid
  43. Turgor
    Pressure that a fluid exerts against a wall, membrane, or other structure that contains it
  44. Active Transport
    Energy-requiring mechanism in which a transport protein pumps a solute across a cell membrane against its concentration gradient
  45. Calcium Pump
    Active transport protein; pumps calcium ions across a cell membrane against their concentration gradient
  46. Passive transport
    Mechanism by which a concentration gradient drives the movement of a solute across a cell membrane through a transport protein, requires no energy input
  47. Endocytosis
    Process by which a cell takes in a small amount of extracellular fluid by the ballooning inward of its plasma membrane
  48. Exocytosis
    Process by which a cell expels a vesicle's contents to extracellular fluid
  49. Phagocytosis
    Cell eating; an endocytic pathway by which a cell engulfs particles such as microbes or cellular debris
  50. Pinocytosis
    Endocytosis of bulk materials
Card Set
Biology Chapter 5
Ground Rules of Metabolism