RP 1: Investigation into the effect of a named variable on the
rate of an enzyme-controlled reaction:
Aim
The effect of temperature on the rate of the reaction catalysed by trypsin
Introduction
Enzymes are globular proteins that act as biological catalysts and collide with the substrate, with
enough energy, to form an enzyme-substrate complex. When they bind they lower the activation
energy and have an induced fit. Products are then reduced As the temperature increases, the
frequency of collisions increases so therefore the frequency of successful collisions will increase.
However, the temperature is also a limiting factor as too much will denature the enzyme (above 40
degrees). Enzyme-controlled reactions will also have other factors such as concentration of enzyme
and substrate and pH but these will need to be controlled to make valid Data. In this experiment, we
are using trypsin which is an enzyme that digests casein. Casein is a protein found in milk. When
trypsin is added to a dilute solution of milk powder, the casein is digested and the solution goes clear.
Hypothesis
As the temperature increases the time taken for the solution with trypsin to turn colourless will
decrease. This will continue until the temperature reaches a certain point after which the curve of the
graph will curve in the opposite direction.
Hazard Risk Safety Precaution Contingency
Broken glass Cuts from sharp Take care when Elevate cuts; apply
object handling glass pressure; do not
objects; keep away remove the glass
from the edge of from the wound;
desk seek medical
assistance
Hydrochloric acid May cause Wear eye protection; Wash off skin
harm/irritation to avoid contact with immediately; flood
eyes or in cuts skin, tie up long hair eye/cuts with cold
water
Hot liquids Burns Handle with care; Run burn under cold
use tongs to remove water; seek medical
boiling tubes from assistance
the water bath
(1)
Apparatus (2)
• 0.5% trypsin solution • 3% solution of milk powder • pH 7 buffer solution • a large beaker to use as a
water bath • test tubes • bungs or cork for test tubes • test-tube rack • stopwatch • marker pen •
pipettes or syringes • thermometer.
rate of an enzyme-controlled reaction:
Aim
The effect of temperature on the rate of the reaction catalysed by trypsin
Introduction
Enzymes are globular proteins that act as biological catalysts and collide with the substrate, with
enough energy, to form an enzyme-substrate complex. When they bind they lower the activation
energy and have an induced fit. Products are then reduced As the temperature increases, the
frequency of collisions increases so therefore the frequency of successful collisions will increase.
However, the temperature is also a limiting factor as too much will denature the enzyme (above 40
degrees). Enzyme-controlled reactions will also have other factors such as concentration of enzyme
and substrate and pH but these will need to be controlled to make valid Data. In this experiment, we
are using trypsin which is an enzyme that digests casein. Casein is a protein found in milk. When
trypsin is added to a dilute solution of milk powder, the casein is digested and the solution goes clear.
Hypothesis
As the temperature increases the time taken for the solution with trypsin to turn colourless will
decrease. This will continue until the temperature reaches a certain point after which the curve of the
graph will curve in the opposite direction.
Hazard Risk Safety Precaution Contingency
Broken glass Cuts from sharp Take care when Elevate cuts; apply
object handling glass pressure; do not
objects; keep away remove the glass
from the edge of from the wound;
desk seek medical
assistance
Hydrochloric acid May cause Wear eye protection; Wash off skin
harm/irritation to avoid contact with immediately; flood
eyes or in cuts skin, tie up long hair eye/cuts with cold
water
Hot liquids Burns Handle with care; Run burn under cold
use tongs to remove water; seek medical
boiling tubes from assistance
the water bath
(1)
Apparatus (2)
• 0.5% trypsin solution • 3% solution of milk powder • pH 7 buffer solution • a large beaker to use as a
water bath • test tubes • bungs or cork for test tubes • test-tube rack • stopwatch • marker pen •
pipettes or syringes • thermometer.
