catalase assay part 1

what is an enzyme

protein that acts as a catalyst and increases reaction rate without having permanent changes to its own structure

what is a substrate

a reactant that an enzyme acts on

enzyme substrate complex

what forms when an enzyme binds to substrate

active site

area on enzyme where the substrate binds

catalase

an enzyme found in all living organisms that are exposed to o2

what does catalase do and why

speeds up the decomposition of hydrogen peroxide to water and o2

• hydrogen peroxide is toxic and damages cells and tissues

what does the liver do?

detoxifies dangerous substances that are consumed by the body by using enzymes such as catalase to help break down toxic substances and make them safer

what was the big question of research paper

how does pH affect catalase activity

what were the results of research paper

catalase works well in normal pH around 4-8.5. the enzyme activity drops when pH is too low or too high

why does activity drop outside a normal pH range

pH changes the shapes on enzymes and enzymes need to be a certain shape to bind to active site

what happens if pH is too low or too high

the bonds break, the enzymes shape changes, and the substrate cant bind

purpose of the lab

to measure catalase acitivty and dermine how ph affects the rate at which catalase breaks down hydrogen peroxide

catalase location

in the peroxisomes of cells and the liver tissue. the liver uses catalase to break to hydrogen peroxide

how is reaction rate measured

As o2 was produced, it displaced the water in the graduated cylinder. the change in placement was recorded and helped measure rate

why was the solution dilluted

to ensure the reaction happens at a measurable rate. if concentration was too high, then the reaction would happen too fast. if concentration was too low, then it would take a really long time

why was a buffer solution used

a buffer solution was used to maintain the same constant pH level throughtout the experiment

key idea of the experiment/lab

The rate of O2 produced affects catalase activity.

• faster production means higher enzyme activity

control

water used to determine if any changes in water level in cylinder were due to anything else other than enzyme

change in control

levels only changed slightly due to liquid injected in a closed system

why did the water displace during control

change is water is not always due to o2, sometimes due to liquid add, this is why we subtract it from the displacement to only measure the o2 production

independant and dependant variable

iv- pH levels. dv- reaction rate

constants

catalase volume, hydrogen peroxide volume, and apparatus system