Enzymes Notes: Part II
Enzymes and their Environment
 All enzymes have an ideal environment that they function in
 Think of them as organisms adapted to their specific
environment and niche
 Who would survive better in Antarctica, a polar bear or a camel?
 What enzyme would be more effective in an acidic environment, a
protease in your stomach or amylase in your mouth?
 What effects enzymes?
 Temperature
 pH
 Enzyme/Substrate Concentration
Denaturing
 When an enzyme loses its structure and becomes non-
functional due to drastic changes in temperature or pH
Temperature
 Every enzyme has an ideal temperature range that it
functions in
 Outside of this range, the enzyme may become
denatured
Enzymes in the Human Body
pH
 What is pH?
 Measure of acidic or basic a solution is
pH and Enzymes
 Every enzyme has an ideal pH range it is used to
working in based on its environment
 Outside of this range, it can become denatured
Enzymes in the Human Body
pH Scale
 Let’s learn more about the pH Scale!
http://www.brainpop.com/science/matterandchemistry/phscale/
Concentration
 How much stuff (solute) is dissolved in a certain
amount of solution (solvent)
 How much enzyme and substrate there are in a
solution can effect how productive the enzyme is
Concentration
 If enzyme concentration is kept constant, and
substrate levels are increased, then, the reaction rate
will increase until it reaches its maximum level
Enzyme Denaturation Review!
 http://www.youtube.com/watch?v=3IL_Df5ouUc
Enzyme Concentration Review!
http://www.kscience.co.uk/animations/mod
el.swf
Do Now
 Identify the BEST pH for the following three enzymes
and identify what pH ranges they would become
denatured.
Example Questions!
 Which of the following most accurately represents the
effects of temperature on enzyme reactions in
humans?
Example Questions!
 Which of the
following most
accurately represents
the effects of
temperature on
enzyme reactions in a
thermophilic
bacteria?
Example Questions!
 The reaction catalyzed by the bacterial enzyme ß-galactosidase forms a
dark-colored end-product when the cells are grown on a particular agar
medium. As more product is formed, the cells become darker. Students
performed an experiment to determine the optimum pH for activity of this
enzyme. Their results are shown in the illustration of bacterial colonies
below.
 Based on these data, the students should conclude that ß-galactosidase
functions best at which pH?
 A. 5 B. 7 C. 9 D. 11
Example Questions!
 All of the following statements are true about
enzymes EXCEPT:
 A. Enzymes are specific to one substrate and reaction
 B. Once enzymes are used once, they can be used over
and over again
 C. Enzymes raise the activation energy of a reaction
 D. Enzymes speed up the rate of reactions
 E. Temperature and pH changes can cause enzymes to
lose their function