In the Krebs cycle, the enzyme-catalyzed transformation involves removal of hydrogen and is best described as which category of reaction?

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Multiple Choice

In the Krebs cycle, the enzyme-catalyzed transformation involves removal of hydrogen and is best described as which category of reaction?

Removing hydrogen in the Krebs cycle is an oxidation reaction because it involves loss of hydrogen atoms (and their electrons) from a molecule to carriers such as NAD+ or FAD, producing NADH or FADH2. Oxidation means the substrate loses electrons, raising its oxidation state. The other categories don’t fit: gaining hydrogen would be reduction, hydrolysis would cleave bonds with water, and substitution would replace an atom in the molecule rather than involving electron transfer. The dehydrogenase steps and formation of NADH/FADH2 illustrate this oxidation process.

Removing hydrogen in the Krebs cycle is an oxidation reaction because it involves loss of hydrogen atoms (and their electrons) from a molecule to carriers such as NAD+ or FAD, producing NADH or FADH2. Oxidation means the substrate loses electrons, raising its oxidation state. The other categories don’t fit: gaining hydrogen would be reduction, hydrolysis would cleave bonds with water, and substitution would replace an atom in the molecule rather than involving electron transfer. The dehydrogenase steps and formation of NADH/FADH2 illustrate this oxidation process.

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