3.1.4.2 Many Proteins are Enzymes Flashcards
Q: What role do enzymes play in biochemical reactions?
A: Enzymes lower the activation energy of reactions, making them proceed more quickly and efficiently.
Q: What is the Induced-Fit Model of enzyme action?
A: The Induced-Fit Model suggests that the enzyme changes shape slightly upon binding with the substrate, which enhances the fit and catalytic activity.
Q: How does the tertiary structure of an enzyme relate to its function?
A: The tertiary structure determines the shape of the enzyme’s active site, which allows it to bind specifically to complementary substrates to form an enzyme-substrate complex
Q: What is enzyme specificity?
A: Enzyme specificity refers to the ability of an enzyme to select and bind to a particular substrate among many possible molecules.
Q: What effect does enzyme concentration have on the rate of an enzyme-controlled reaction?
A: Increasing enzyme concentration typically increases the rate of reaction, provided there is sufficient substrate.
Q: How does substrate concentration affect enzyme activity?
A: Increasing substrate concentration increases the rate of reaction until all enzyme active sites are occupied; after this point, further increases in substrate concentration do not affect the rate.
Q: What is the effect of competitive inhibitors on enzyme activity?
A: Competitive inhibitors compete with the substrate for the enzyme’s active site, which can reduce the rate of reaction.
Q: How do non-competitive inhibitors affect enzyme activity?
A: Non-competitive inhibitors bind to a site other than the active site, causing a change in enzyme shape and reducing its activity regardless of substrate concentration.
Q: How do pH and temperature influence enzyme activity?
A: Each enzyme has an optimal pH and temperature range. Deviations from these optimal conditions can reduce enzyme activity or denature the enzyme.
Q: How have models of enzyme action evolved over time?
A: Models have evolved from the Lock-and-Key Model, which suggested a rigid fit, to the Induced-Fit Model, which describes a more flexible interaction between enzyme and substrate.
Q: What is the importance of enzymes in intracellular and extracellular reactions?
A: Enzymes are crucial for various biochemical reactions that determine cellular processes and overall organism function.
Q: What variables should be controlled in an enzyme activity experiment?
A: Variables to control include temperature, pH, enzyme concentration, substrate concentration, and the presence of inhibitors.
Q: How can you calculate the uncertainty of measurements in an enzyme experiment?
A: Uncertainty can be calculated by determining the range of possible values and considering measurement errors.
Q: How do you find the initial rate of an enzyme-controlled reaction from a graph?
A: Use a tangent to the curve at the start of the reaction on a graph of product concentration versus time to determine the initial rate.
