Which reactions of the citric acid cycle transfer energy as NADH?

Verified step by step guidance

1. Identify the reactions in the citric acid cycle where NAD+ is reduced to NADH.
2. Recall that the citric acid cycle, also known as the Krebs cycle, involves a series of enzymatic reactions that occur in the mitochondria.
3. Recognize that NADH is produced in the citric acid cycle during specific dehydrogenation reactions.
4. List the specific steps in the citric acid cycle where NADH is generated: (1) Isocitrate to α-ketoglutarate, (2) α-ketoglutarate to succinyl-CoA, and (3) Malate to oxaloacetate.
5. Understand that in each of these steps, a dehydrogenase enzyme catalyzes the reaction, facilitating the transfer of electrons to NAD+, forming NADH.

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. It plays a crucial role in cellular respiration by oxidizing acetyl-CoA to produce energy carriers. The cycle generates NADH and FADH2, which are essential for the electron transport chain, ultimately leading to ATP production.

NADH Production

NADH is a reduced form of nicotinamide adenine dinucleotide (NAD+), a key electron carrier in cellular metabolism. During the citric acid cycle, specific reactions, such as the conversion of isocitrate to alpha-ketoglutarate and malate to oxaloacetate, involve the reduction of NAD+ to NADH. This process captures energy that can later be used to generate ATP.

Energy Transfer in Metabolism

Energy transfer in metabolism refers to the conversion of biochemical energy from nutrients into usable forms, primarily ATP. In the citric acid cycle, the transfer of electrons to NAD+ to form NADH is a critical step in this process. The NADH produced carries high-energy electrons to the electron transport chain, where they are used to create a proton gradient that drives ATP synthesis.