ENZYMES
There are thousands of reactions that occur within organisms. These reactions would occur very slowly or not at all without enzymes.
Reactions can: Build new molecules Break down molecules + Break down molecules + Enzymes speed up theses chemical reactions. Enzymes are catalysts.
Enzymes are not changed by the reaction. Lock & Key: Specific substrate attaches to specific enzyme product substrate active site enzyme Enzymes are not changed by the reaction.
How do enzymes speed up reactions? Activation energy the energy required to start a reaction Enzymes lower the activation energy
Temperature pH ( acids & bases) How well an enzyme works depends on: Enzyme are sensitive to temp and pH.
Temperature and Activity of Enzyme Enzyme has greatest activity Human enzymes 37° reaction rate temperature
Temperature and Activity of Enzyme Human enzymes 37° reaction rate temperature Enzyme has lowest activity Enzyme is inactive
Temperature and Activity of Enzyme Human enzymes 37° reaction rate temperature The activity of the enzyme decreases at temperatures above and below the optimum temperature.
Temperature and Activity of Enzyme Human enzymes At which temperature is the activity of the enzyme the greatest? 37° reaction rate temperature
100 °C Some bacteria thrive at extreme temperatures. -10 °C
pH Scale Acid Base
pH and Activity of Enzyme Stomach pepsin Intestine trypsin Optimum pH = 3 Optimum pH = 8 reaction rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH Each enzyme works best at a specific pH.
The activity of the enzyme decreases at pH Stomach pepsin Intestine trypsin reaction rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH The activity of the enzyme decreases at pH above and below the optimum temperature.
According to the graphs above, which enzyme is the least affected by pH?
The stomach is very acidic and has a pH of 2 The stomach is very acidic and has a pH of 2. Enzyme X breaks down proteins into amino acids in the stomach. According to the graphs above, which enzyme is enzyme X?
A B C The stomach has a pH of 2 and the small intestine has a pH of 7. Starches are broken down in the small intestine. Which enzyme above will break down starch in the small intestine?