Peroxidase is present in all aerobic cells and is also functional in plants. Peroxidase catalyzes the decomposition of peroxide into water and oxygen bubbles. Peroxisomes in the liver convert the hydrogen found in alcohol, and other toxins, into oxygen the body can use. The hydrogen peroxide formed during the metabolism of peroxisome is toxic to the body. The liver contains an enzyme that converts this hydrogen peroxide into water.

In Plants

Plant peroxisomes, called glyoxysomes, are found in the fatty tissues in plants. The glyoxysomes initiate the transformation of fatty acids into sugar. The sugar may be used as an energy source for new seedlings. Peroxisomes in plants are located near mitochondria and chloroplasts to aid in metabolic functions. Hydrogen peroxidase functions to decompose the spontaneous arrival of toxic hydrogen peroxide.

Lab: Enzyme Activity

In a lab experiment on Enzymes And Enzyme Activity, used a rat liver homogenate, assorted water temperature, different enzyme concentration and pH effects to ascertain under which conditions the enzymes were most efficient. The pieces of filter paper were soaked in the homogenate. The soaked filter paper was then pressed against the inner wall of a glass bottle. Hydrogen peroxide was then poured into the bottle and the bottle was sealed. At the point that the bottle was inverted and placed inside a water bath of desired temperature, the homogenate and the hydrogen peroxide interacted. The measurements of the oxygen bubbles taking the place of the liquid in a graduated cylinder revealed the levels of hydrogen peroxide that was decomposed and transformed into oxygen and water.

Effects of Temperature on Enzyme Activity

To explain the effects of temperature on enzyme reaction at the molecular level, we used water bath treatments at <10 degrees C, 37 degrees C and .40 degrees C. We concluded that enzymes were happily reacting at a higher rate in the room temperature water bath of 37 degrees C.

Effects of Enzyme Concentration on Enzyme Activity

In order to explain the effects of enzyme concentration on enzyme activity, we saturated ½, 1 and 2 strips of rat liver homogenate in isolated experiments. Our findings were that as the concentration of the enzyme treatment increased, the enzyme reaction increased as well. Finally, we tested the effect of PH on enzyme activity using neutral (N), acidic (HCl) and basic (NaOH) pH treatments. We found that the more basic the pH treatment, the greater the enzyme reaction.

The peroxidase reaction can be viewed as: 2H2O2 à 2H2O + O2. In other words, two molecules of hydrogen peroxide decompose to yield two molecules of water and one molecule of oxygen.

Peroxidase is an essential metabolic process in the liver. The decomposition of toxic hydrogen peroxide is essential to maintaining healthy aerobic cells.

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