The Effect of Increasing Concentrations of Formaldehyde on the Cellular Respiration in Columba Livia Liver Cells

Abstract

INTRODUCTION

Cellular respiration is one of the most important processes in the cell due to its catabolic effects that were able to produce ATP and other energy sources needed for biosynthesis and performing the cell function with the help of enzymes in catalyzing these reactions. Enzymes are proteins that aid in catalyzing and quickening the process, but inhibitors may compete with these enzymes or on substrates binding with each other that may permanently or temporarily hinder the action of the enzyme. An example of an inhibitor is formaldehyde (HCHO) which is a substance commonly used to preserve decaying bodies due to its ability to stop cellular respiration, avoid desiccation, and induces cell apoptosis.

METHODS

In the experiment, pigeon liver homogenate was used along with the addition of the substrate, succinate, and increasing concentrations of formaldehyde (5%, 10%, and 15%) was added to determine its effectiveness as an inhibitor. The solutions were added with dichlorophenolindophenol (DPIP) to monitor its reduction and measure its respiration rate using spectrophotometry with 605nm. The RESULTS were recorded and tabulated. The average and partial respiration rates were also computed.

RESULTS

The OD605 readings of tubes containing pigeon liver homogenate, liver homogenate with succinate, liver homogenate with succinate and 5% HCHO, liver homogenate with succinate and 10% HCHO, and liver homogenate with succinate and 15% HCHO, along with DPIP. inTube 1, there was no reduction of DPIP which was added to the solution before being read by the spectrophotometer, indicating respiration. inTube 2, the same conditions were observed as in Tube 1. inTubes 3 to 5 where increasing HCHO concentrations were added (5%, 10%, and 15%), the trend is generally decreasing, indicating respiration and reduction of DPIP.

DISCUSSIONS

Formaldehyde is synthesized from methanol with pungent odor and produces gases that are readily absorbed by the body at high concentrations and is converted to formic acid which inhibits the cellular respiration by binding to the cytochrome c and cytochrome a oxidases, which leads to acidosis wherein too much acid was produced and occurs at conditions such as poisoning of alcohols or severe dehydration. Results show that the concentrations used were not enough to inhibit cellular respiration. However, formaldehyde inhibits cellular respiration theoretically, and higher concentrations may inhibit the process.