DETERMINING THE GLUCOSE CONTENT OF AND ORANGE USING GOD
DETERMINING THE GLUCOSE CONTENT OF AND ORANGE USING GOD-PAP ASSAY
Every fruit has a sweet taste only that some are sweeter than others. The sweetness of most fruits come from its sugar content and these sugars that the fruits contain are known as invert sugars. In this experiment, an orange was used. An orange which is an excellent source of vitamin C gets its sweetness from natural sugars which are sucrose, glucose and fructose (livestrong.com). In this experiment the concentration of glucose in an orange was measured. There are various methods which can be used to measure the glucose concentration but in this experiment a highly specific enzymatic method using the GOD-PAP assay (glucose oxidase peroxidase aminophenazone phenol) (schedule coventry,2013). This assay is based on 2 coupled enzyme reactions and a colorimetric end-point.
D-glucose + O2 +H2O → H2O2 + gluconate aminophenazone + phenol + H2O2 → a red dye + H2O2
Under stable conditions, absorbance measured using a spectrophotometer will be proportional to the amount of glucose present (schedule Coventry,2013). Spectrophotometry is a method used to measure absorbance of light. This measurement is carried out using a spectrophotometer. A spectrophotometer is an equipment used to take accurate measurement of absorbance at various wavelengths. Electrons are usually present at different energy levels but are usually at ground state (stationary state) which is the lowest energy level. When electrons are exposed to energy such as heat or light they become excited. One quantum of energy is absorbed for an electron to become excited (from ground state to excited state) and for it to go back to its ground state one quantum of energy is released. There are two laws surrounding the absorbance of light in a solution known as the Beer-lambert relationship. These laws state that the absorption of light is exponentially related to the concentration of the solute. It also states that the absorption of light is
Every fruit has a sweet taste only that some are sweeter than others. The sweetness of most fruits come from its sugar content and these sugars that the fruits contain are known as invert sugars. In this experiment, an orange was used. An orange which is an excellent source of vitamin C gets its sweetness from natural sugars which are sucrose, glucose and fructose (livestrong.com). In this experiment the concentration of glucose in an orange was measured. There are various methods which can be used to measure the glucose concentration but in this experiment a highly specific enzymatic method using the GOD-PAP assay (glucose oxidase peroxidase aminophenazone phenol) (schedule coventry,2013). This assay is based on 2 coupled enzyme reactions and a colorimetric end-point.
D-glucose + O2 +H2O → H2O2 + gluconate aminophenazone + phenol + H2O2 → a red dye + H2O2
Under stable conditions, absorbance measured using a spectrophotometer will be proportional to the amount of glucose present (schedule Coventry,2013). Spectrophotometry is a method used to measure absorbance of light. This measurement is carried out using a spectrophotometer. A spectrophotometer is an equipment used to take accurate measurement of absorbance at various wavelengths. Electrons are usually present at different energy levels but are usually at ground state (stationary state) which is the lowest energy level. When electrons are exposed to energy such as heat or light they become excited. One quantum of energy is absorbed for an electron to become excited (from ground state to excited state) and for it to go back to its ground state one quantum of energy is released. There are two laws surrounding the absorbance of light in a solution known as the Beer-lambert relationship. These laws state that the absorption of light is exponentially related to the concentration of the solute. It also states that the absorption of light is
References: 1. Reed,R.,Holmes,D.,Weyers,J.,Jones,A. (2007) Practical Skills in Biomolecular Sciences, 3rd edn., Essex: Pearson. 2. Ochs,C (2010) Natural Sugars in Oranges, Available at: www.livestrong.com/article/267094-natural-sugars-in-oranges/ (Accessed: 15th November 2013). 3. Coventry University. Schedule 116 BMS.(2013) Determination Of The Glucose Content O An Orange