Question

Reflect and Apply There is a reaction in which succinate reacts with FAD to give fumarate and \(\mathrm{FADH}_{2}\) In this reaction, which substance is oxidized, and which is reduced? Which substance is the oxidizing agent, and which is the reducing agent?

Short answer

Succinate is oxidized and is the reducing agent. FAD is reduced and is the oxidizing agent.

Step-by-step solution

Identify the Substances Involved

Examine the reaction: succinate reacts with FAD to give fumarate and \(\text{FADH}_2\). The substances involved are succinate, FAD, fumarate, and \(\text{FADH}_2\).

Determine Oxidation States

Consider the changes in oxidation states for the substances involved. Succinate is converted to fumarate, and FAD is converted to \(\text{FADH}_2\).

Identify the Oxidized Substance

Oxidation involves the loss of electrons. Succinate loses electrons and is converted into fumarate, thus succinate is oxidized.

Identify the Reduced Substance

Reduction involves the gain of electrons. FAD gains electrons and hydrogen to become \(\text{FADH}_2\), thus FAD is reduced.

Determine the Oxidizing Agent

The oxidizing agent is the substance that gets reduced, as it accepts electrons. Since FAD is reduced, FAD is the oxidizing agent.

Determine the Reducing Agent

The reducing agent is the substance that gets oxidized, as it donates electrons. Since succinate is oxidized, succinate is the reducing agent.

Key concepts

succinate and fumarate

In biochemistry, succinate and fumarate are key players in the citric acid cycle, which is vital for cellular respiration. Succinate is a four-carbon molecule and acts as a substrate. When succinate reacts and loses electrons, it transforms into fumarate. This oxidation process is crucial in the generation of energy within the cell.

The transformation involves a specific enzyme called succinate dehydrogenase which catalyzes this reaction. This enzyme helps strip away electrons from succinate, allowing it to form fumarate. Knowing the role of succinate and fumarate helps us understand broader metabolic processes.

Succinate's role as an electron donor and fumarate's as a product show how energy conversion takes place at a molecular level.

FAD and FADH2

FAD (flavin adenine dinucleotide) and FADH2 play essential roles in cellular energy metabolism. FAD is a redox-active coenzyme associated with various proteins. When involved in reactions like the succinate to fumarate conversion, FAD acts as an electron acceptor.

During the reaction, FAD accepts two electrons and two hydrogen atoms, reducing to form FADH2. This reduction is vital because FADH2 carries the electrons into the electron transport chain, which ultimately contributes to the production of ATP, the cell’s energy currency.

The conversion of FAD to FADH2 in this biochemical reaction highlights its importance in energy production and cellular respiration. FADH2 ultimately produces about 1.5 ATP molecules when it donates its electrons in the electron transport chain.

oxidizing agent and reducing agent

Understanding oxidizing and reducing agents is critical in analyzing oxidation-reduction reactions. In the reaction where succinate converts to fumarate and FAD converts to FADH2, we identify these roles. The oxidizing agent accepts electrons, causing another substance to be oxidized. Here, FAD accepts electrons and hydrogen atoms during its conversion to FADH2, making it the oxidizing agent.

Conversely, the reducing agent donates electrons, causing another substance to be reduced. Succinate donates electrons in this reaction, converting it to fumarate and thus is the reducing agent.

Identifying these agents helps us understand the transfer of electrons and how energy transformations are managed in biochemical pathways. This foundational knowledge is applicable across numerous oxidation-reduction reactions in biochemistry.