Enzymes Revision Questions
The diagrams show a protease enzyme catalysing the breaking of part of a protein molecule into
smaller pieces. Which diagram has three correct labels?
The graph shows how the rate of an enzyme-controlled reaction changes with temperature.
What describes the shape of the graph
within the temperature range marked X?
A The rate of reaction decreases.
B The rate of reaction increases then
decreases.
C The rate of reaction reaches a
maximum.
D The reaction is occurring at the
optimum temperature
Six test-tubes were set up at different pH values. They each contained the same quantity of
starch and amylase in water. The table shows the time taken for the reaction to be
completed in
each test-tube.
At which pH does the amylase work best?
A pH 1 B pH 5 C pH 7 D pH 11
The apparatus shown is used for an experiment on starch digestion. Which test-tube contains the
most sugar after 20 minutes?
Four test-tubes were set up as shown in the table. In which test-tube would starch be broken down
the fastest?
Which graph
shows the effect
of temperature on
the activity of a
human digestive
enzyme?
Starch is digested by amylase in the mouth, but it is not digested in the stomach.
What is the reason for this?
A All starch digestion is completed in the mouth.
B The pH in the stomach is not suitable for the amylase to work.
C The starch does not stay in the stomach long enough to be digested.
D The temperature in the stomach is not suitable for the amylase to work.
11 The temperature of an enzyme-controlled reaction is increased by 10°C. How does this affect the
rate of reaction? A It always increases the rate. B It always decreases the rate. C It may increase or
decrease the rate. D It has no effect on the rate.