Memorize Enzyme Inhibition

Summary

This video explains the three types of enzyme inhibition: competitive, uncompetitive, and non-competitive. It breaks down the phenomena in which the inhibitor affects the enzyme's activity by competing with the substrate for the active site or binding to the enzyme-substrate complex. The video also demonstrates how to memorize the graphs of each inhibition type using a simple pencil technique, illustrating how the values of 1/Vmax and 1/Km change in each case, providing a clear and visual method for remembering enzyme inhibition concepts.

Takeaways

• 😀 Competitive inhibition occurs when the substrate and the inhibitor compete for the enzyme's active site.
• 😀 Uncompetitive inhibition happens when the inhibitor binds to the enzyme-substrate (ES) complex.
• 😀 Non-competitive inhibition involves the inhibitor binding either to the active site or directly to the ES complex.
• 😀 The graph of competitive inhibition shows no change in 1/V max but a change in -1/Km.
• 😀 To memorize the graph for competitive inhibition, hold the pencil at 1/V max and rotate it anti-clockwise.
• 😀 For uncompetitive inhibition, place the pencil on the graph and push it upwards to memorize its graph.
• 😀 Uncompetitive inhibition causes changes in both 1/V max and -1/Km.
• 😀 In non-competitive inhibition, rotate the pencil at -1/Km to get the graph, which shows changes in 1/V max but not in -1/Km.
• 😀 The key to memorizing the graphs involves manipulating the pencil based on specific values of 1/V max and -1/Km.
• 😀 Reviewing competitive inhibition: rotate the pencil at 1/V max, for uncompetitive inhibition push it upwards, and for non-competitive inhibition rotate at -1/Km.

Q & A

What are the three types of enzyme inhibition?

The three types of enzyme inhibition are competitive inhibition, uncompetitive inhibition, and non-competitive inhibition.

What happens in competitive inhibition?

In competitive inhibition, the inhibitor competes with the substrate for binding at the enzyme's active site.

How does the graph of competitive inhibition differ from other types?

In competitive inhibition, the value of 1/Km changes, but the value of 1/V_max remains the same.

What is the technique for memorizing the graph of competitive inhibition?

To memorize the graph of competitive inhibition, place the pencil at 1/V_max and rotate it counterclockwise.

How is uncompetitive inhibition defined?

Uncompetitive inhibition occurs when the inhibitor binds only to the enzyme-substrate (ES) complex.

What changes on the graph in uncompetitive inhibition?

In uncompetitive inhibition, both 1/Km and 1/V_max values change.

What is the technique for memorizing the graph of uncompetitive inhibition?

To memorize the graph of uncompetitive inhibition, push the pencil upwards on the graph.

What defines non-competitive inhibition?

In non-competitive inhibition, the inhibitor can bind either to the enzyme's active site or the enzyme-substrate (ES) complex.

What happens on the graph during non-competitive inhibition?

In non-competitive inhibition, the value of 1/Km remains the same, while the value of 1/V_max changes.

What is the technique for memorizing the graph of non-competitive inhibition?

To memorize the graph of non-competitive inhibition, hold the pencil at 1/Km and rotate it counterclockwise.