Lab -- properties of enzymes Flashcards
exergonic
free energy of products are less than free energy of reactants
able to occur spontaneously
activation energy
initial input of energy that must be supplied to before a reaction that involves covalent bonds can proceed
required to bring the reacting molecules close enough and in the proper orientation for the reaction b/n them to proceed
effect of catalyst on activation energy
catalyst greatly reduces activation energy requirement
enzymes
biological catalysts
greater quantity of enzyme = (faster/slower) rate of reaction
faster
alkaline phosphatase
an enzyme normally catalyzes the removal of phosphate (PO4 3-) from molecules w/in a cell
para-nitrophenyl-phosphate (pNPP)
synthetic substrate of alkaline phosphatase
hydrolysis of pNPP produces ___ which is a ___ color
para-nitrophenol (pNP) – yellow color
yellow substances, like pNP, tend to absorb ___ light
blue
greater concentration of pNP == (more/less) blue light it absorbs == (higher/lower) absorbance
more blue light it absorbs
higher absorbance
as enzyme concentration increases…
abs/min increases
rate of reaction increases because more enzyme catalyzes the production of more yellow pNP –>
more yellow pNP == blue light is absorbed
as substrate concentration increases…
abs/minute increases but peaks eventually at substrate concentration of 1.0-1.6 M
ideal pH for max abs/min…
idea pH is 10
below or above, abs/min starts to drop
abs/min of reaction is the same as…
rate of reaction
what is the relationship b/n pH and initial reaction rate?
proteins need a specific range of pH to be effective. Outside of this range, proteins will begin to denature (change shape) and become less effective. This is why reaction rate begins to decrease
