INTRODUCTION:
The rate of respiration can be affected by many different factors; including temperature, oxygen
availability and the type of substrate. Temperature affects respiration by increasing the kinetic
energy, speeding up the rate at which respiration occurs. Different substrates affect respiration
based on their structure as a monosaccharide or a disaccharide. A low oxygen availability limits the
rate of respiration. I am going to investigate the effect of different substrates on the rate of
respiration.
HYPOTHESIS:
I believe that glucose will be the substrate producing the most amount of carbon dioxide gas as,
glucose is a monosaccharide. The disaccharides would take longer to produce the same amount of
carbon dioxide as they contain bonds between the molecules, which would need to be broken
before it can react.
VARIABLES:
Control: I will keep the sugar solutions and yeast at a constant temperature of 40 degrees to
prevent temperature from affecting the rate of respiration.
Independent: I will change the different sugar solutions in each reaction, in order to
investigate how substrate affects the rate of respiration.
Dependent: I will be measuring the volume of carbon dioxide gas produced in the gas
syringe.
EQUIPTMENT
10% sugar solution (glucose, fructose, sucrose, maltose)
5% yeast solution
50 cm3 Measuring cylinder (x2)
Gas syringe
Clamp
Clamp stand
Stopwatch
Conical flask
Delivery tube with a bung
The rate of respiration can be affected by many different factors; including temperature, oxygen
availability and the type of substrate. Temperature affects respiration by increasing the kinetic
energy, speeding up the rate at which respiration occurs. Different substrates affect respiration
based on their structure as a monosaccharide or a disaccharide. A low oxygen availability limits the
rate of respiration. I am going to investigate the effect of different substrates on the rate of
respiration.
HYPOTHESIS:
I believe that glucose will be the substrate producing the most amount of carbon dioxide gas as,
glucose is a monosaccharide. The disaccharides would take longer to produce the same amount of
carbon dioxide as they contain bonds between the molecules, which would need to be broken
before it can react.
VARIABLES:
Control: I will keep the sugar solutions and yeast at a constant temperature of 40 degrees to
prevent temperature from affecting the rate of respiration.
Independent: I will change the different sugar solutions in each reaction, in order to
investigate how substrate affects the rate of respiration.
Dependent: I will be measuring the volume of carbon dioxide gas produced in the gas
syringe.
EQUIPTMENT
10% sugar solution (glucose, fructose, sucrose, maltose)
5% yeast solution
50 cm3 Measuring cylinder (x2)
Gas syringe
Clamp
Clamp stand
Stopwatch
Conical flask
Delivery tube with a bung
