Learn: Core Practical 4 - Enzyme and Substrate Concentration

Welcome!You've already studied factors affecting enzyme activity, including temperature and pH. Now, let's explore how enzyme and substrate concentrations impact reaction rates. This builds on your understanding of enzymes as biological catalysts.

What is Core Practical 4?This experiment investigates how varying concentrations of enzymes and substrates affect the initial rate of enzyme-catalysed reactions. It helps demonstrate the relationship between concentration and reaction rate, and is important for understanding enzyme kinetics.

Enzyme ConcentrationIncreasing enzyme concentration generally increases the reaction rate because more active sites are available for substrate binding. However, this effect plateaus when all substrate molecules are bound, as the reaction becomes substrate-limited.

Substrate ConcentrationIncreasing substrate concentration initially increases the reaction rate because more substrate molecules collide with active sites. However, once all active sites are occupied, the reaction rate reaches a maximum and no longer increases.

Experimental SetupIn this practical, you will measure how varying enzyme and substrate concentrations affect the rate of reaction. A common example is investigating the breakdown of hydrogen peroxide by catalase, where oxygen production is measured.

Measuring Rate of ReactionThe initial rate of reaction is calculated by measuring the product formed or substrate used over time. This is often determined graphically from the steepest part of the curve or using data tables.

Review Time!Great work! You've learned about enzyme and substrate concentrations, their effects on reaction rates, and how to measure the initial rate of reaction. Let's test your understanding with a few questions.

Well done!You've completed the lesson on enzyme and substrate concentration and their effects on reaction rate. These principles are important for understanding enzyme kinetics and biological processes. Keep building on your practical skills!