Chem Lab #35

  1. What are 3 drastic conditions a chemist might use to aide a chemical reaction?
    very acidic, very basic, or high temp.
  2. Define: Catalyst
    A compound that will speed up the rate of the reaction without being consumed in the overall process.
  3. A typical example of a catalyst would be the hydrolysis of ______ to form glucose and fructose.
  4. Sucrose (C12H22O11) + H2O = ______ + _____
    Glucose + Fructose
  5. If sucrose were placed in water by itself, the sugar would take a _____ amount of time to break up.
  6. If 20% acid is added to sugar, the acid catalyst will (speed up or slow down) the reaction and allow the sucrose to hydrolyzed in about 30 min. at 50*C.
    speed up
  7. Does the addition of acid cause immediate hydrolysis of sucrose?
  8. Can enzyems be used as a catalyst?
  9. Define: Enzymes
    the biochemicals that catalyze the sythesis and breakdown of biochemical molecules.
  10. Under physiological temperatures (37*C) the enzyme called _____ will catalyze the breakdown of sucrose in a matter of seconds.
  11. Starch units are broken down into simpler _______.
  12. What enzyme breaks down starch and where is it found?
    Ptyalin, which is found in saliva
  13. Does the activity, or rate of action, of the ptyalin varies or stay the same from person to person?
  14. Define: Ptyalin Number
    the number of milliliters of 1% starch soluction taht can be digested in 30min. by 1ml of saliva.
  15. A soluction of starch will turn what color when mixed with a few drops of iodine solution?
    dark blue
  16. When starch becomes hydrolzed to the smaller carb fragments, what happens to the color?
    the color disappears
  17. What characteristic of the starch-enzyme solution indicates the starch has been hydrolyzed?
    when it reaches the achromic (colorless) point
  18. Amylose structure of starch --> ________
  19. Sucrose ---> _____
  20. What is the formula to find the ptyalin number?
    Ptyalin number = ?ml starch/ ?ml saliva
  21. What is a major difference between an enzyme and an ordianary catalyst?
    Enzymes cause the reaction rate to be much faster than an ordinary catalyst would.
  22. If the ptyalin number is to be measured with a 1% starch solution, why is a 2% starch solution employed in this experiment?
    The 3ml of 2% starch is the same as 6ml of 1% starch solution. So, 6ml of 1% starch solution required 0.03ml of saliva to reach the achromic point.
  23. Why does a cracker taste sweet after it has been in your mouth for a while?
    Ptyalin, an enzyme found in saliva, breaks down starch into carbs.
  24. The complete hydrolysis of starch yields what simple sugar?
Card Set
Chem Lab #35
The Enzymatic Breakdown of Starch