RP 1 Flashcards
give examples of variables that could affect the rate of an enzyme controlled reaction
enzyme conc./ vol
substrate conc./vol
temperature of solution
pH of solution
inhibitor conc.
decribe how temperature can be controlled
use a thermostatically controled water bath
monitor using a thermometer at regular intervald and add hot/cold water is temperature fluctuates
describe how pH can be controlled
use a buffer solution
monitor using pH meter at regualar intervals
why were the enzyme and substrate solutions left in the water bath for 10 min before mixing
so solutions equilibrate to reach temperature of water bath
describe a control experiment
use denatured enxymes
everything else the same - same conc and vol substrate and exyme, same type and volume of buffer, same temp
describe how the rate of an enzyme-controlled reaction can be measured
measure time taken for reaction to reach a set point eg. conc. volume mass
rate = 1/time
measure conc./vol/mass throughout reaction
plot on graph with time on x axis
draw tangent at t=0
initial rate = change in y/change in x
suggest a safety risk and explain how to reduce this risk
handling enzymes may cause an allergic reaction
avoid contact with skin by wearing gloves and eye protection
explain why using a colorimeter to measure colour change is better than comparison to colour standards
not subjective
more accurate
explain a procedure that could be used to stop each reaction
boil /add strong acid —> denature enzyme
put in ice —> lower kinetic energy so no E-S complexes
add high conc. of inhibitor —> no E-S complexes form
describe how processed data can be presented as a graph
IV on x axis rate on y
linear number sequence with appropriate scale
plot coordinates as crosses
join piping to point with straight lines or draw smooth curve
explain why the rate of reaction decreases over time throughout each experiment
initial rate is highest as substrate conc. not limiting
reaction slows as substrate used up and stops when no substrate left
