ENZYMES
Student Name ______________________________
1:
1) What term is used to describe a cellular reaction in which large molecules are broken down to smaller
ones?________________________________________
2) What is metabolism? ________________________________________
3) Give an example of a catabolic reaction in an animal________________________________________
4) Give an example of an anabolic reaction in a plant________________________________________
5) Is energy release a feature of anabolic or catabolic reactions? ________________________________
6) To which group of molecules do enzymes belong? ________________________________________
7) Name an enzyme and matching substrate ________________________________________
8) What is an enzyme? _________________________________________________________________
9) Name an enzyme that is involved in the digestion of fat _____________________________________
10) True or false?-- Immobilised enzymes can act as catalysts ____________________________________
11) What is a bioreactor? _______________________________________________________________
12) State one advantage of using an immobilised enzyme in a bioreactor. __________________________
________________________________________________________________________________
13) What term best describes the shape of an enzyme? ________________________________________
14) Suggest a temperature at which human enzymes work best. _________________________________
15) In the case of cold alcohol (ethanol) state the following:
(a) An investigation in which you used it ________________________________________
(b) The precise purpose for its use in the investigation that you have indicated ___________________
____________________________________________________________________________
16) What is an amylase? ________________________________________
Name a site of amylase action. ________________________________________
What is the approximate pH value at this site? ________________________________________
17) What is meant by immobilisation? ______________________________________________________
18) Name a substance that is used to immobilise enzymes. ____________________________________
19) Give two advantages of using immobilised enzymes. ______________________________________
________________________________________________________________________________
20) Give one application of a named immobilised enzyme. In your answer, refer to substrate, enzyme and product.
__________________________________________________________________________
21) Is an enzyme a lipid, a protein or a carbohydrate? ________________________________________
22) Where in a cell are enzymes produced? ________________________________________
23) Name an enzyme that turns fats to fatty acids and glycerol. _________________________________
24) What is meant by an enzyme’s optimum pH? ________________________________________
25) What is a denatured enzyme? ________________________________________
26) Answer the following in relation to a lipase:
(a) Where is it secreted? ________________________________________
(b) Where does it act? ________________________________________
(c) What is the approximate pH at its site of action? ________________________________________
27) Amylase is an enzyme that is found in saliva. State the substrate and the product of this enzyme.
________________________________________________________________________________
28) (a) Name a carbohydrate-digesting enzyme in the human alimentary canal._____________________
(b) Where in the alimentary canal does this enzyme act? ___________________________________
(c) State the enzyme’s product(s). ________________________________________
2. Explain each of these terms:
1 Metabolism _________________________________________________________________
2 Enzyme _________________________________________________________________
3 Catalyst _________________________________________________________________
4 Substrate _________________________________________________________________
8 Optimum pH _________________________________________________________________
9 Buffer tablet _________________________________________________________________
21 Bioprocessing _________________________________________________________________
24 *Specific _________________________________________________________________
25 *Active site _________________________________________________________________
26 *Denatured _________________________________________________________________
27 *Induced fit theory _______________________________________________________________
28 *Enzyme-substrate complex ________________________________________________________
6. Hydrogen peroxide is a liquid that slowly changes to water and oxygen gas over a number of weeks.
Catalase can speed up this reaction. We make catalase in our liver. A student used the apparatus
shown to investigate the effect of different temperatures on catalase action.
At each temperature, 2 cm3 of hydrogen peroxide was dropped on to a 1 cm3 cube of liver. The
volume of gas collected in two minutes at each temperature was measured. The results are shown
in the following table.
EMPERATURE (°C) 0 10 20 30 40 50 60
(a) Use the figures in the table to plot a graph of
the results.
(b) (i) At which temperature is most oxygen produced?
_______________________
Explain the likely reason. _______________________
______________________________________________
(ii) What volume of oxygen would be produced at 25°C?
_______________________
(iii) At what temperature would a volume of 80 cm3 of
oxygen be produced? _______________________
(c) At 60°C no oxygen was produced. What would happen if this same cube of liver was cooled to
30°C and another 2 cm3 of hydrogen peroxide was added? Explain your answer.
_____________________________________________________________________
(d) Besides temperature, name another factor that might affect the rate of action of this enzyme.
_______________________
17. Complete these sentences:
(a) Enzymes _________________up the rate of chemical _______________________
(b) Enzymes are _______________________ because they only work on one substrate.
(c) The substrate fits into the _______________________site on the surface of the _____________
(d) With an increase in __________________the rate of reaction __________________
(e) But eventually a temperature is reached which ____________________ the enzyme.
(f) Enzymes can be re-used, so only ________________ amounts are needed.