Name: _________________________
Biology 135
Enzymes Webquest
Enzymes
Enzymes are vital chemicals in all living things. They are proteins that speed
up, and control, the chemical reactions inside the cells. If enzymes do not function
properly, the cell or even the whole organism can die. This chapter will look at
enzymes, and also some deficiency diseases, where people are born with a lack of
a particular enzyme.
A)
Web site name: FCCJ
Web URL: http://web.fccj.org/~dbyres/enzyme1.html
Read “Mechanisms of Enzyme Action”
1).
What are the two main roles of enzymes? ___________________________
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
2).
What is a “substrate”? ___________________________________________
3).
In the first diagram (with sucrose), is the substrate broken apart into two
products, or are two substrates joined to make a single product?
_____________________________________________________________
4).
What are two ways that the barrier of activation energy can be overcome?
_____________________________________________________________
_____________________________________________________________
5).
If the temperature of an enzyme controlled reaction increased from 10oC to
30oC, the reaction rate will typically :
a) double
b) triple
c) quadruple
d) increase 9-fold
6).
What happens to most enzymes above 50oC ? ________________________
_____________________________________________________________
7).
Which organisms have enzymes that can work efficiently at –2oC ?
_____________________________________________________________
Name: _________________________
Biology 135
Enzymes Webquest
8).
What is the optimum pH for pepsin? _______________________________
9).
What is inhibition? _____________________________________________
10). Chemicals that are very similar to the true substrate are ________________
inhibitors.
11). Why are non-competitive inhibitors unaffected by substrate concentration?
_____________________________________________________________
_____________________________________________________________
12). What is a “prosthetic group”? _____________________________________
13). Why does the stomach lining not get digested by pepsin? _______________
_____________________________________________________________
14). What type of reaction is done by Lyases? ___________________________
15). How are the following enzymes used commercially?
a) Substilin : __________________________________________________
b) Glucose oxidase : ____________________________________________
B)
Web site name: Maricopa Community College
Web URL: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookEnzym.html#Enzymes
Read “Enzymes: Organic Catalysts”
16). What is a “catalyst”? ____________________________________________
17). How do catalysts lower the activation energy? ________________________
_____________________________________________________________
18). Carbonic anhydrase causes chemicals to react ________ times faster than
without the enzyme.
Name: _________________________
Biology 135
Enzymes Webquest
19). What is the “induced fit hypothesis”? _______________________________
_____________________________________________________________
20). What are “thermolabile enzymes” ? ________________________________
_____________________________________________________________
21). What is the optimum pH for the enzyme Arginase? ____________________
22). How does sulfanilamide kill bacteria? ______________________________
_____________________________________________________________
23). Which of the four competitive inhibitors shown in the diagram is the most
similar in structure to succinate? __________________________________
24). What effect do the following inhibitors have ?
a) nerve gas : _________________________________________________
c) Penicillin : _________________________________________________