Catalase Assay Flashcards
what was the purpose of this lab? how was this measured?
to examine the effects of pH on catalase activity
-to measure enzymatic activity of the enzyme catalase
-measured by collecting oxygen gas that was released as catalase broke down hydrogen peroxide. can measure water displacement in graduated cylinder
what are enzymes? why do our bodies use enzymes?
enzymes are proteins that speed up the rate of reactions without being consumed by the reactions
-our bodies use enzymes to speed up reactions without increasing our body temperature above normal level
how do enzymes speed up the rate of reaction? what is this called?
by decreasing the amount of energy required to start a reaction
-called activation energy
what is a substrate? what is an enzyme-substrate complex? what happens during this complex?
- the reactant an enzyme acts on
- when the enzyme binds to the substrate(s) it forms an enzyme-substrate complex
- while joined, the enzyme converts the substrates into the products
when does the enzyme release the substrate? how fast does this reaction occur?
after it has been turned into the product
-typical enzyme molecule acts on ~1000 molecules per second
why are enzyme catalyzed reactions specific? what causes this?
because enzymes will only recognize and bind to its specific substrate(s)
-an enzymes unique 3D shape determined by its linear sequence of amino acids
what is the active site?
the region in which a substrate binds to an enzyme
what does catalase do? where is catalase located, where is this found in high concentrations?
accelerates the breakdown of hydrogen peroxide to water and oxygen. H2O2 –> H2O + 1/2 O2
- located in peroxisomes (organelle in eukaryotic cells)
- found in high concentrations in the liver
why was it important to hold the flask at its neck, and not by the base?
because the heat from your hand is enough to significantly change the volume of gas in the apparatus.
what did it mean if it took < 1 min for the water level to stop dropping? what if it was still dropping after 3 minutes?
- meant that it took less than 1 minute for all the hydrogen peroxide to be broken down into water an oxygen and therefore the catalase solution was too strong and needed to be diluted
- if after three minutes the water was still dropping it meant that the dilution was to weak and needed to be made more concentrated
what was the Null Hypothesis for this experiment? what was the alternative hypothesis?
pH will have no effect on the rate of oxygen production (ml/sec) of Beef (Bos taurus) liver catalase.
-pH will have an effect on the rate of oxygen production (ml/sec) of Beef (Bos taurus) liver catalase.
what was the control in this experiment? what was the purpose of this control?
- distilled water
- this control was a negative control to ensure that no enzyme activity was occurring while non added catalase was present
