Refer to the diagram of the citric acid cycle in Figure 12.11 to answer each of the following:


d. Name the reactions where secondary alcohols are oxidized to ketones.

Verified step by step guidance

1. Identify the structure of secondary alcohols in the citric acid cycle. Secondary alcohols have the hydroxyl group (-OH) attached to a carbon atom that is also connected to two other carbon atoms.
2. Look for reactions in the citric acid cycle where a secondary alcohol is converted to a ketone. This involves the oxidation of the alcohol group.
3. Recall that oxidation in organic chemistry often involves the loss of hydrogen atoms or the gain of oxygen atoms.
4. In the citric acid cycle, the conversion of isocitrate to α-ketoglutarate involves the oxidation of a secondary alcohol to a ketone.
5. Another example is the conversion of malate to oxaloacetate, where a secondary alcohol is oxidized to a ketone.

Key Concepts

Citric Acid Cycle

The citric acid cycle, also known as the Krebs cycle, is a series of enzymatic reactions that occur in the mitochondria, playing a crucial role in cellular respiration. It involves the oxidation of acetyl-CoA to produce energy in the form of ATP, as well as electron carriers like NADH and FADH2. Understanding this cycle is essential for identifying specific reactions, such as the oxidation of secondary alcohols to ketones.

Oxidation of Alcohols

Oxidation of alcohols refers to the chemical process where alcohols lose electrons, often resulting in the formation of carbonyl compounds. In the context of the citric acid cycle, secondary alcohols are specifically oxidized to ketones through the action of dehydrogenase enzymes. This transformation is significant as it contributes to the overall energy yield of the cycle.

Enzymatic Reactions

Enzymatic reactions are biochemical processes facilitated by enzymes, which are proteins that act as catalysts to speed up chemical reactions. In the citric acid cycle, specific enzymes are responsible for the oxidation of secondary alcohols to ketones, ensuring that these reactions occur efficiently and at a biologically relevant rate. Understanding the role of these enzymes is key to identifying the specific reactions in the cycle.