Exploring Enzyme Catalysis and Reaction Rates

Mr. Anderson introduces enzyme catalysis, focusing on catalase, an enzyme that breaks down hydrogen peroxide into water and oxygen. The video explains enzyme functions using lactase as an example and describes a lab experiment using yeast to measure reaction rates. It discusses how factors like temperature and pH affect enzyme activity, providing insights into optimal conditions for enzyme function.

What is the primary function of the enzyme catalase?

• To break down water into hydrogen and oxygen

• To synthesize hydrogen peroxide from water and oxygen

• To convert water into hydrogen peroxide

• To break down hydrogen peroxide into water and oxygen

Which of the following best describes an enzyme?

• A biological molecule that acts as a catalyst

• A molecule that is consumed in a reaction

• A product of a chemical reaction

• A reactant in a chemical reaction

What does the enzyme lactase break down?

• Glucose

• Sucrose

• Lactose

• Fructose

In the lab experiment, what is used to measure the rate of the reaction?

• The pH level of the solution

• The amount of hydrogen peroxide remaining

• The time it takes for filter paper to float

• The temperature of the solution

What happens to the filter paper if there is no yeast on it?

• It floats immediately

• It changes color

• It sinks and stays at the bottom

• It dissolves in the solution

Why do we measure the rate in 'floats per second'?

• Because it is a standard unit of measurement

• To account for the time it takes for the paper to float

• To measure the amount of yeast

• To measure the concentration of hydrogen peroxide

Why does the reaction rate not continue to increase linearly with more yeast?

• Because there is a limited amount of hydrogen peroxide

• Because the yeast becomes inactive

• Because the filter paper dissolves

• Because the temperature decreases

How does temperature affect enzyme activity?

• Higher temperatures always increase enzyme activity

• Lower temperatures always increase enzyme activity

• Temperature has no effect on enzyme activity

• Enzyme activity increases to an optimal point and then decreases

What happens to an enzyme when it denatures?

• It becomes more active

• It speeds up the reaction

• It produces more substrate

• It changes shape and loses function

How does pH affect enzyme activity?

• pH has no effect on enzyme activity

• Enzyme activity peaks at an optimal pH and decreases on either side

• Enzyme activity is highest at extremely basic pH

• Enzyme activity is highest at extremely acidic pH