Required Practical 1 - Rate of Enzyme-Controlled Reaction (Colorimter Use) Flashcards
Suggest why a colorimeter is used
- provides quantitative result
- more accurate (not subjective)
- easier to compare
Suggest why a water bath is used over a Bunsen burner
- stable temperature
- uniform heating
- safer since no open flame
Suggest the importance of calibrating a colorimeter using a control
- consistent readings
- container and buffer solution absorb light as well so provides a base line
Suggest why a buffer solution is used in investigations not measuring effect of pH on enzyme activity
- maintains constant pH
- pH is controlled variable
Suggest why it is important never to touch the sides of a cuvette
Fingerprints affect the absorbance reading on colorimeter
Suggest why a colourless buffer solution should be used in a colorimeter
Coloured buffer solution would affect the absorbance reading on colorimeter
Suggest why solutions are mixed gently before placed in a colorimeter
Avoids formation of bubbles or froth which significantly affect absorbance reading on colorimeter
Suggest why test tubes are left in the water bath for a period of time before the reaction
- temperature can equilibrate
- reach temperature for reaction to occur
Suggest why a water bath at room temperature is used
- keeps test tubes at a constant temperature
- room air temperature fluctuates
Describe and explain what you did to make sure the temperatures of the water baths were as reliable as possible
- measure temperature before and after each reaction
- ensure there is little/no change