In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: About free radicals:
Options: <0> They are compounds that contain two or three unpaired electrons in an outer orbital. <1> Reactive oxygen species (ROS) in the cell are only generated enzymatically. <2> Hydrogen peroxide is the most damaging radical in the cell. <3> The hydroxyl radical originates non-enzymatically (Heber-Weiss reaction) and damages proteins and DNA. <4> Oxygen is a triradical.
chemistry

Question: COMPLETE: in the Krebs cycle 4 oxidation reactions occur, in 3 of them the final acceptor electron is ___ and in the other is ___:
Options: <0> FAD / FMN. <1> NAD + / FMN. <2> NADP + / FAD. <3> NAD + / FAD. <4> FAD / NAD +.
chemistry

Question: A columbimetrica valuation:
Options: <0> It is always done at controlled potential. <1> Always use a platinum macroelectrode. <2> It does not need a system indicating the end point. <3> You need the current to be controlled. <4> You always need the titrant to be added from a burette.
chemistry