Yeast Respiration Lab
“Investigate the factors affecting the rate of yeast respiration”
Lab Report
Introduction
The aim of this experiment was to investigate the effect of different amounts of a substrate on the respiration rate of yeast and to compare this to the effect of different amounts of glucose on the rate of yeast respiration. The substrate which I chose to further investigate was fructose. Fructose is a fruit sugar which is one of the three, along with glucose and galactose, dietary monosaccharides that are directly absorbed into the bloodstream during digestion.
Apparatus
2% yeast solution Large beaker Small beaker Conical flask Thermometer (˙C) Glass rod pH meter & data logger Hot water Sensitive digital scale (g) Fructose (1.0g, 1.5g, 2.0g, 2.5g) Glucose (1.0g, 1.5g, 2.0g, 2.5g) Measuring cylinder (cm3)
Variables
Independent: Concentration of glucose (1.0g, 1.5g, 2.0g, 2.5g) , concentration of fructose (1.0g, 1.5g, 2.0g, 2.5g)
Dependent: Amount of carbon dioxide produced, i.e. rate of yeast respiration
Controlled: 2% yeast solution (20cm3), initial temperature of yeast solution (35-40˙C), amount of time that the reaction is measured (180 seconds)
Method
All apparatus was collected and safety precautions (hair tied back, safety goggles and lab coat) applied 20cm3 of 2% yeast solution was measured out, using the measuring cylinder, and poured into the conical flask 1.0 ±0.5g of glucose was weighed out on the sensitive digital scale Hot water was then poured into a large beaker into which the conical flask, containing the 2% yeast solution, was held in place in, with a thermometer inside The conical flask was held like this until the 2% yeast solution reached an initial temperature between 35-40˙C (specific temperature was noted down) When this temperature was reached, the thermometer was taken out of the conical flask and the conical flask out of the hot water 1.0
Lab Report
Introduction
The aim of this experiment was to investigate the effect of different amounts of a substrate on the respiration rate of yeast and to compare this to the effect of different amounts of glucose on the rate of yeast respiration. The substrate which I chose to further investigate was fructose. Fructose is a fruit sugar which is one of the three, along with glucose and galactose, dietary monosaccharides that are directly absorbed into the bloodstream during digestion.
Apparatus
2% yeast solution Large beaker Small beaker Conical flask Thermometer (˙C) Glass rod pH meter & data logger Hot water Sensitive digital scale (g) Fructose (1.0g, 1.5g, 2.0g, 2.5g) Glucose (1.0g, 1.5g, 2.0g, 2.5g) Measuring cylinder (cm3)
Variables
Independent: Concentration of glucose (1.0g, 1.5g, 2.0g, 2.5g) , concentration of fructose (1.0g, 1.5g, 2.0g, 2.5g)
Dependent: Amount of carbon dioxide produced, i.e. rate of yeast respiration
Controlled: 2% yeast solution (20cm3), initial temperature of yeast solution (35-40˙C), amount of time that the reaction is measured (180 seconds)
Method
All apparatus was collected and safety precautions (hair tied back, safety goggles and lab coat) applied 20cm3 of 2% yeast solution was measured out, using the measuring cylinder, and poured into the conical flask 1.0 ±0.5g of glucose was weighed out on the sensitive digital scale Hot water was then poured into a large beaker into which the conical flask, containing the 2% yeast solution, was held in place in, with a thermometer inside The conical flask was held like this until the 2% yeast solution reached an initial temperature between 35-40˙C (specific temperature was noted down) When this temperature was reached, the thermometer was taken out of the conical flask and the conical flask out of the hot water 1.0