Question

Zellweger syndrome is one of a class called Peroxisome Biogenesis Disorders (PBD). PBDs are characterized by abnormalities of the liver, kidney, brain, and skeletal system. Zellweger syndrome is particularly severe and death usually occurs by age 6 months. There is an absence of functional peroxisomes. One of the roles of peroxisomes is to render \(\mathrm{H}_{2} \mathrm{O}_{2}\) nontoxic by A. oxidizing amino acids with \(\mathrm{O}_{2}\) B. the action of the enzyme catalase. C. transporting \(\mathrm{H}_{2} \mathrm{O}_{2}\) from blood into peroxisomes. D. the action of cathepsins. E. shortening of a fatty acid chain.

Short answer

Answer: The main role of peroxisomes in rendering H2O2 nontoxic is through the action of the enzyme catalase, which breaks down hydrogen peroxide into water (H2O) and oxygen (O2) gas.

Step-by-step solution

Understanding the role of peroxisomes

First, it's important to understand the role of peroxisomes in the cell. Peroxisomes are small, membrane-bound organelles found in eukaryotic cells that are involved in various metabolic processes such as detoxification of harmful substances, metabolism of fatty acids, and decomposition of hydrogen peroxide (H2O2).

Evaluating Option A

Option A suggests that peroxisomes render H2O2 nontoxic by oxidizing amino acids with O2 (oxygen). While peroxisomes are involved in oxidation reactions, this is not the primary mechanism they use to detoxify H2O2. So, option A is incorrect.

Evaluating Option B

Option B states that peroxisomes render H2O2 nontoxic through the action of the enzyme catalase. Catalase is an enzyme found in peroxisomes that breaks down hydrogen peroxide into water (H2O) and oxygen (O2) gas, thus detoxifying it. This is the correct function of peroxisomes in the context of handling H2O2. So, option B is the correct answer.

Evaluating options C, D, and E for completion

Even though we have already identified the correct role of peroxisomes in detoxifying H2O2, let's evaluate the remaining options for a better understanding: C. Peroxisomes do not primarily transport H2O2 from the blood into peroxisomes. They are more involved in breaking it down once it's inside the organelle. D. Cathepsins are a family of protease enzymes involved in the lysosome function, not peroxisome function. E. Peroxisomes are involved in shortening fatty acid chains through beta-oxidation, but this is not related to the detoxification of H2O2. In conclusion, the correct option is:

Answer

B. The action of the enzyme catalase renders H2O2 nontoxic in peroxisomes.