Problem 17 - Biology

Question

What is the effect of an inhibitor binding an enzyme? a. The enzyme is degraded. b. The enzyme is activated. c. The enzyme is inactivated. d. The complex is transported out of the cell.

Step-by-Step Solution

Answer

c. The enzyme is inactivated.

Step 1: Understanding Enzymes and Inhibitors

Enzymes are biological catalysts that accelerate chemical reactions inside cells. Inhibitors are molecules that decrease the activity of enzymes.

Step 2: Types of Inhibition

Inhibitors can bind to enzymes and reduce their activity. This binding usually results in a decrease in enzyme function or complete inactivation.

Step 3: Considering the Options

Evaluate each given option based on the effect of an inhibitor on an enzyme: a. The enzyme is degraded: Enzyme degradation is generally not the result of inhibitor binding. b. The enzyme is activated: Inhibitors do not activate enzymes; they decrease their activity. c. The enzyme is inactivated: Inhibitors often result in the enzyme being inactivated. d. The complex is transported out of the cell: Inhibitor binding does not typically cause the enzyme to be transported out of the cell.

Step 4: Conclusion

Based on the understanding and evaluation, the correct answer to the effect of an inhibitor binding an enzyme is that the enzyme is inactivated.

Key Concepts

enzyme activity

Enzyme activity refers to the ability of an enzyme to catalyze a chemical reaction. Enzymes are specific to substrates and work best under certain conditions. This activity is crucial for processes such as digestion, metabolism, and DNA replication. Each enzyme has an **active site** where the substrate binds, forming an enzyme-substrate complex. Catalytic action then transforms the substrate into products, which are released, allowing the enzyme to act again. This relationship ensures that biological processes occur at necessary speeds for life. An inhibitor can decrease or stop this activity by interfering with the active site or altering the enzyme's shape.

biological catalysts

Enzymes function as biological catalysts. Unlike non-biological catalysts, enzymes are highly specific. They only catalyze specific reactions for specific substrates. This specificity is due to the unique shape of their active sites. This precise match between enzyme and substrate is often described using the 'lock and key' model or the 'induced fit' model.
Enzymes work by ➡️ lowering the activation energy of reactions, which allows them to occur more efficiently. They are vital in pathways such as glycolysis and the citric acid cycle.
Key points about biological catalysts:

• They are not consumed in the reactions they catalyze.
• They can be reused multiple times.
• They operate best at optimal temperature and pH levels.

inhibitor binding

Inhibitor binding refers to the process by which molecules called inhibitors attach to enzymes. This binding can take place at the active site or elsewhere on the enzyme. There are different types of inhibitors:

• **Competitive inhibitors**: These bind to the active site, directly competing with the substrate.
• **Non-competitive inhibitors**: These bind to a different part of the enzyme, causing a change in its shape and thus reducing its activity.
• **Uncompetitive inhibitors**: These bind only to the enzyme-substrate complex, preventing the reaction from completing.

The main consequence of inhibitor binding is a reduced enzymatic activity, often leading to complete inactivation.
This detailed understanding is critical for fields like drug design, where inhibitors can be used to regulate enzyme activity for therapeutic benefits.