biology Ch 5

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biology Ch 5
2013-02-27 00:09:02
Biology chapter

things to know.
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  1. energy
    the capacity to do work
  2. Kinetic energy
    the energy of motion.- light, heat, ect.
  3. potential energy
    energy that is stored. ex: gas in my gas tank.
  4. First law of Thermodynamics 
    Energy can not be created or destroyed.
  5. Second law of Thermodynamics.
    Energy tends to disperse spontaneously. 
  6. Entropy
    Measure of how much the energy of a system is dispersed.
  7. What are the differences between Kinetic energy and potential energy?
    Kinetic energy is in motion and potential energy is being stored.
  8. Explain energy flow.
    from the environment -> to producers ->consumers -> back to environment.
  9. Reactant
     a molecule that enters a reaction
  10. Product
    A molecule that remains at the end of a reaction.
  11. Endergonic
    Describes a reaction that requires a net input of free energy to proceed.(energy in) Store energy
  12. Exergonic
    Describes a reaction that ends with a net release of free energy. (releases energy) 
  13. Activation Energy
    Minimum amount of energy required to start a reaction.
  14. Catalysis
    The acceleration of a reaction by a molecule that is unchanged by participating in the reaction.
  15. Substrate 
    A molecule that is specifically acted upon by an enzyme.
  16. Active state
    Of an enzyme, pocket in which substrates bind and a reaction occurs.
  17. Transitional State
    Point during a reaction at which substrate bonds reach their breaking point and the reaction will run spontaneously.
  18. Induced-fit modle
    The concept that substrate binding to an active site of an enzyme improves the fit between the two molecules.
  19. What is the function of an enzyme?
    It acts as a catalysis, it helps a reaction happen faster.
  20. What are the mechanisams of an enzyme?
    • Helping substrates get together
    • Orienting substrates in positions that favor reaction.
    • Inducing a fit between enzyme and substrate
    • Shutting out water molecules.
  21. Metabolic pathway
    Series of enzyme-mediated reactions by which cells build, remodel  or break down an organic molecule.
  22. Feedback inhabition
    mechanism in which a change that results from some activity decreases or stops the activity.
  23. Allosteric
    Describes a region of an enzyme that can bind a regulatory molecule and is not the active site.
  24. Redox reaction
    Oxidation- reduction reaction, in which one molecule accepts electrons( it becomes reduced) from another molecule( which becomes oxidized).
  25. 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.
  26. Heme
    is a small organic compound with an iron atom at its center.
  27. Cofactor
    A metal ion or a coenzyme that associates with an enzyme and is necessary for its function.
  28. Coenzyme
    An organic molecule that is a cofactor.(they carry chemical groups,atoms,or electrons from one reaction to another in a metabolic pathway.
  29. Antioxidant
    Substance that prevents oxidation of other molecules.
  30. Phosphprylation
    Transfer of a phosphate group from one molecule to another.
  31. ATP
    The nucleotide adenosine triphosphate.
  32. 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.
  33. Fluid mosaic
    Molecule of a cell membrane as a two-denominational fluid of mixed composition.
  34. Adhesion proteins
    fasten cells together in the plasma membrane of animal cells. A membrane protein.
  35. Recognition protein
    Plasma membrane protein that identifies a cell as belonging to self (one's own body).
  36. Receptor proteins
    Plasma membrane protein that binds to a particular substance outside of the cell.
  37. Transport protein
    Protein that passively or actively assists specific ions or molecules across a membrane.
  38. Diffusion
    Spontaneous spreading of molecules or ions in a liquid or gas.
  39. There are 5 factors that effect how quickly diffusion occurs:
    • Size
    • Temperature
    • Concentration
    • Charge
    • Pressure
  40. Concentration
    Number of molecules or ions per unit volume.
  41. Concentration gradient
    Difference in concentration between adjoining regions of fluid.
  42. Hypotonic
    Describes a fluid that has a low overall solute concentration relative to another fluid.
  43. Hypertonic
    Describes a fluid that has a high overall solute concentration relative to another fluid.
  44. Isotonic
    Describes two fluids with equal solute concentration.
  45. Osmosis
    The diffusion of water across a selectively permeable membrane in response to a concentration gradient.
  46. Turgor
    Pressure that a fluid exerts against a wall, membrane, or other structure that contains it.
  47. Osmotic pressure
    Amount of turgor that prevents osmosis into cytoplasm or other hypertonic fluid.
  48. active transport
    Energy-requiring mechanism in which a transport protein pumps a solute across a cell membrane against its concentration gradient.
  49. Calcium pump
    Active transport protein; pumps calcium ions across a cell membrane against their concentration gradient.
  50. 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.
  51. Endocytosis
    process by which a cell takes in a small amount of extracellular fluid by the ballooning inward of its plasma membrane.
  52. Exocytosis
    Process by which a cell expels a vesicle's contents to extracellular fluid.
  53. phagocytosis
    "Cell eating"; an endocytic pathway by which a cell engulfes particles such as microbes or cell debris.
  54. pinocytosis
    Endocytosis of bulk materials