Lab Enzyme Function

In which tubes did hydrogen peroxide get broken down into water and oxygen

Catalase + Hydrogen Peroxide

Which of the following combinations demonstrate that the enzyme catalase is specific for the substrate hydrogen peroxide

Catalase + Water

How is the temperature of the chemical reaction in this experiment controlled?

Catalase is either heated or cooled before adding the substrate.

What is required for the reaction to work

Catalase solution Hydrogen Peroxide Solution

Which of the following factors can affect the rate of a chemical reaction

How much substrate is avalible The pH in which the enzyme is active The Temperature of the reaction How much enzyme is avalible.

It is essential that the catalase is properly equilibrated to the cold, warm, and hot temperatures before this experiment starts. Why is this?

Temperature is the independent variable in the expirament and must be set accurately

At optimum pH:

The active site of an enzyme closely matches the shape of its substrate

If catalase is present in excess, reducing the amount of hydrogen peroxide in the reaction mix will _____________ the amount of oxygen gas formed

decrease

Raising the pH or lowering the pH from the optimal pH of an enzyme will __________ the activity

decrease

A graph constructed to show the relationship between enzyme concentration and enzyme activity would have ________ plotted on the x-axis and _____ plotted on the y-axis

enzyme concentration ; bubble column height

If enough substrate is present, adding more enzyme to a reaction mixture will ___________ the rate of product formation

increase

enzymes below their optimal temperature will show ________ activity

less

An enzyme at its optimum pH will produce a column of bubbles that is higher than when it is not at its optimum ph because it is _________ active

more

Catalase activity can be detected by:

observing formation of oxygen bubbles

The activity of catalase can be measured as the rate of:

oxygen formation and hydrogen peroxide breakdown

Based on your results in this experiment, catalase has a pH optimum of

7

What is true about enzyme activity and pH?

At pH's above or below optimum, conversion of subtrate to product happens more slowly Enzymes at their optimum pH will be most active An enzyme converts substrate to product most quickly at optimum pH

What are the reasons to measure the height of the bubble column exactly 20 seconds after combining the catalase with the hydrogen peroxide?

At shorter or longer times the difference in enzyme concentration might not correlate to bubble height The timing must be standardized between the tubes.

Enzymes heated up at very high temperatures can lose activity due to which of the following.

Denaturation

What is the purpose of prepaering a tube with water and hydrogen peroxide?

It is a negative conrolled expirament.

If you have a constant amount of substrate and add an increasing concentration of enzyme, what will happen to the reaction rate?

It will increase

Increasing the concentration of enzyme at the beginning of the experiment results in __________ substrate interacting with the enzyme per unit of time

More

When the enzyme catalase is mixed with water are oxegen bubbles produced?

No

When an enzyme is at its optimum pH

Product is formed at the fastest rate

At refrigerator temperatures catalase is expected to produce few bubbles of oxygen. Why is this?

Substrate molecules move more slowley and interact with the active site less frequently.

Catalase is the enzyme that catalyzes the reaction that breaks down hydrogen peroxide to oxygen and water. What will happen as the reaction between catalase and hydrogen peroxide proceeds?

The amount of hydrogen peroxide decreases and the amount of oxygen gas formation increases.

Compared to the other test tubes, what did you observe when catalase reached its optimum pH

The bubbles were at their highest

What will happen if the test tubes are left to react for an hour instead of 20 seconds?

The bubbles will burst All the tubes will have produced approximately the same amount of bubbles The bubbles will no longer be formed

At very high temperatures enzymes can exhibit less activity or none at all. Which of the following could explain this.

The enzyme has denatured and cannot interact with the substrate The active site has changed shape so that the substrate does no longer fit properly

Heating up a solution of molecules will result in which of the following?

The molecules will bump into eachother with a greater frequency The molecules will move around faster

In the concentration exercise, which test tube produced the highest column of bubbles after the same amount of time?

The one with the most enzyme.

Different Types of Enzymes may differ in optimal temperature and pH requirements, depending upon where and how they function

True

Three test tubes are set in a rack and contain the following: Tube 1: 4ml Hydrogen Peroxide & 3 ml catalase Tube 2: 4 ml hydrogen peroxide & 1ml catalase Tube 3: 4ml hydrogen peroxide & 7ml catalase In which tube will you observe the highest column of bubbles.

Tube 3