Temperature and Catalytic Functions of β-galactosidase
September 12, 2012
All life forms and cells process chemical reactions (Barnhart and Hopper, 2012).Chemical reactions either bind or break bonds between atoms. Greater amounts of energy are necessary to have the chemical reaction with higher concentrations. Sometimes the chemical reactions need a push to reach enough energy.
Activation energy is that extra push of energy to reach that necessary amount of energy. This can be achieved by either heat or a catalyst. More heat is more energy and a catalyst in the form of an enzyme will lower the amount of energy needed to reach the reaction.
Reactants are the initial molecule or molecules and the product is the outcome molecule(s). Each individual enzyme will act as a catalyst to only one reactant due to its very particular shape. Denaturation can destroy enzymes with an advanced temperature (Brooker Widmaier Graham Stiling,2011).
Galactosidase (enzyme that comes from E. coli) is the catalyst to the breakdown of lactose to the monosaccharides galactose and glucose. The enzyme only breaks down when lactose is ready to be broken down as nourishment to the body.
Lactose, glucose, and galactose are all colorless so the spectrophotometer alone wouldn’t properly monitor their concentrations so ONPG is added. ONPG is also colorless but it produces a yellow chemical called nitrophenol.
Competetitive inhibition is where multiple substrates are competeting for the same enzyme causing not all substrates to bind to the enzyme. I hypothesis that higher the temperature of the molecules faster they will reach activation and that the control will have higher absorbance.
We set the wavelength of the spectrophotometer to 420 nm and gathered all the needed materials (cuvettes, stirrer, buffer, ONPG solution of galactosidase (enzyme) solution. Calibratde the transmittance to zero on...