Enzyme Action, Factors, And Inhibition Flashcards
(15 cards)
What is an enzyme?
A protein that acts as a biological catalyst, speeding up chemical reactions in living organisms
What is a catalyst?
A substance that speeds up a reaction without being consumed or changed by the reaction
How do enzymes speed up reactions?
By lowering the activation energy required for the reaction to occur, essentially making it easier for the reactants to transform into products
Explain the lock-and-key model
Enzymes have a specific active site that matches the shape of their substrate (reactant) perfectly. This allows for a highly specific reaction to occur, akin to a key fitting into a lock
Describe the induced-fit model
The enzyme’s active site can slightly change shape to accommodate the substrate, optimizing the reaction
What is an enzyme-substrate complex?
The temporary complex formed when an enzyme binds to its substrate at the active site
How does temperature affect enzyme activity?
At its optimum temperature, an enzyme’s activity is at its highest level. Increasing temperature initially increases the reaction rate, but at very high temperatures, the enzyme denatures (loses its shape) and activity decreases dramatically
How does pH affect enzyme activity?
Enzymes have an optimum pH. Deviations from this pH can alter the enzyme’s shape and affect its activity
What is enzyme denaturation?
The irreversible change in an enzyme’s structure (shape) due to extreme temperature or pH, causing it to lose its function
How does substrate concentration affect enzyme activity?
As substrate concentration increases, enzyme activity increases until all enzyme active sites are occupied (saturation)
What is competitive inhibition?
An inhibitor molecule competes with the substrate for the enzyme’s active site, preventing substrate binding, thus reducing the number of enzyme-substrate complexes formed.
What is non-competitive inhibition?
An inhibitor binds to a location other than the active site, (called the allosteric site), altering the enzyme’s shape and reducing its activity
What is activation energy?
The minimum energy required to start a chemical reaction
How do enzymes lower activation energy?
By providing an alternative reaction pathway with a lower energy barrier
How does lowering activation energy affect reaction rate?
It speeds up the reaction
