Enzyme Function 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 transport oxygen in the blood

• To convert glucose into energy

• To break down hydrogen peroxide

• To synthesize proteins

Which of the following best describes an enzyme?

• A molecule that is consumed in a reaction

• A biological molecule that acts as a catalyst

• A product of a chemical reaction

• A reactant in a chemical reaction

In the example given, what does the enzyme lactase do?

• It synthesizes lactose from glucose

• It transports lactose across cell membranes

• It converts lactose into energy

• It breaks down lactose into glucose and galactose

What is the purpose of using filter paper in the catalase experiment?

• To act as a substrate for the enzyme

• To provide a surface for yeast growth

• To measure the temperature of the reaction

• To observe the breakdown of hydrogen peroxide

How is the rate of reaction measured in the catalase experiment?

• By counting the number of bubbles produced

• By measuring the time taken for the filter paper to float

• By observing the color change in the solution

• By weighing the amount of yeast used

What happens to the reaction rate as the concentration of yeast increases?

• It decreases linearly

• It remains constant

• It increases and then levels off

• It decreases exponentially

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

• The yeast becomes inactive

• The filter paper dissolves

• The hydrogen peroxide is depleted

• The temperature of the solution drops

What effect does increasing the substrate concentration have on the reaction rate?

• It decreases the reaction rate

• It has no effect on the reaction rate

• It increases the reaction rate

• It stops the reaction completely

How does temperature affect enzyme activity?

• Enzyme activity is highest at freezing temperatures

• Enzyme activity increases to an optimal point and then decreases

• Enzyme activity decreases with increasing temperature

• Temperature has no effect on enzyme activity

What happens to enzymes in extreme pH conditions?

• They denature and lose function

• They become more active

• They change their substrate

• They replicate faster