when a biological molecule is oxidized, the electrons are often captured by nad. with that knowledge, identify if the substrate in each reaction is being oxidized or reduced.
Based on the information provided by LectureNotes, when a biological molecule is oxidized, the electrons are often captured by NAD+. In light of this knowledge, we can determine whether the substrate in each reaction is being oxidized or reduced.
To understand whether a substrate is being oxidized or reduced, we need to determine the change in oxidation state of the substrate.
- If the oxidation state of the substrate increases, it means that the substrate is being oxidized.
- If the oxidation state of the substrate decreases, it means that the substrate is being reduced.
It is important to note that oxidation and reduction always occur together and are known as redox reactions.
Let’s look at an example:
Reaction: Glucose + NAD+ → Glucose-6-phosphate + NADH + H+
In this reaction, the glucose molecule is being oxidized to form glucose-6-phosphate. Here, the carbon atoms in glucose lose electrons to NAD+ and hence, the oxidation state of the carbon atoms increases. Therefore, in this reaction, glucose is being oxidized.
Similarly, in a reaction where a substrate gains electrons, it is being reduced.
Remember that NAD+ acts as an electron carrier, accepting electrons from oxidized molecules and becoming reduced to NADH. In this process, the substrate molecule loses electrons and is oxidized, while NAD+ gains electrons and is reduced to NADH.
By analyzing the change in oxidation state and the role of NAD+, we can determine whether the substrate in each reaction is being oxidized or reduced.