Ethylene glycol (HO—CH₂—CH₂—OH) is a major component of antifreeze. If ingested, it is first converted to HOOC—CHO (oxoethanoic acid) and then to HOOC—COOH (oxalic acid), which is toxic.
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a. What class of enzyme catalyzes the reactions described?

Verified step by step guidance

1. Step 1: Begin by identifying the type of chemical reaction occurring in the problem. The conversion of ethylene glycol to oxoethanoic acid and then to oxalic acid involves the addition of oxygen atoms and the removal of hydrogen atoms, which is characteristic of oxidation reactions.
2. Step 2: Recall that enzymes are biological catalysts that facilitate specific types of reactions. For oxidation reactions, the class of enzymes responsible is known as oxidoreductases.
3. Step 3: Oxidoreductases are a broad class of enzymes that catalyze oxidation-reduction reactions. These enzymes typically involve the transfer of electrons, often with the help of cofactors such as NAD+ or FAD.
4. Step 4: In this specific case, the enzyme catalyzing the conversion of ethylene glycol to oxoethanoic acid and then to oxalic acid would likely be a subclass of oxidoreductases, such as alcohol dehydrogenase or aldehyde dehydrogenase, which are known to oxidize alcohols and aldehydes, respectively.
5. Step 5: Conclude by noting that the class of enzyme catalyzing the described reactions is oxidoreductases, as they are responsible for facilitating the oxidation of ethylene glycol to its toxic metabolites.

Key Concepts

Enzymes

Enzymes are biological catalysts that accelerate chemical reactions in living organisms. They are typically proteins that lower the activation energy required for reactions, allowing them to occur more quickly and efficiently. Each enzyme is specific to a particular substrate and reaction, facilitating processes such as metabolism and detoxification.

Oxidoreductases

Oxidoreductases are a class of enzymes that catalyze oxidation-reduction reactions, where the transfer of electrons occurs between molecules. In the context of ethylene glycol metabolism, these enzymes play a crucial role in converting the compound into its toxic metabolites by facilitating the necessary chemical transformations through electron transfer.

Metabolic Pathways

Metabolic pathways are series of interconnected biochemical reactions that occur within a cell, leading to the conversion of substrates into products. In the case of ethylene glycol, the metabolic pathway involves its conversion to oxoethanoic acid and subsequently to oxalic acid, highlighting the importance of enzymes in regulating these processes and their implications for toxicity.