Question

A student coming out cell fractionation of a tissue and forgot to label his tubes. The contents of one tube when studied showed organelles bounded by the membrane with an activity of catalase enzyme. These organelles could be:
A. SER
B. Chloroplast
C. Lysosome
D. Peroxisome

Answer 1

The cytoplasm consists of a jelly-like homogenous ground substance the cytosol, which contains organelles, inclusions, and a variety of organic and inorganic materials. The organelles include ER, Golgi, lysosomes, microbodies, vacuoles, etc.

Complete answer: Smooth endoplasmic reticulum is made up of mainly tubules and vesicles and is free of ribosomes. It lies near the cell membrane and is well developed in the muscle cells, adipose tissue cells, interstitial cells, glycogen storing liver cells, adrenal cortex cells, spermatocytes, leukocytes and the cells that synthesize and secrete steroids. These help in the synthesis of lipids, carries enzyme bodies, the glycosomes, for glycogen metabolism in the liver cells, detoxification of liver and formation of organelles like Golgi apparatus, lysosomes and vacuoles.
Chloroplasts are the most common type of plastids that are of prime importance in plants as these are the site of photosynthesis in plants. These chloroplasts vary in form, size and number but have a uniform structure.
Lysosomes are organelles containing 50 different hydrolyzing or digestive enzymes called acid hydrolyzing enzymes like nuclease, phosphatase, glycosidase, sulfatase, lipase, etc. These are popularly called as suicide bags.
Peroxisomes are abundant in the liver and kidney cells of the vertebrates. They are also found in other organs such as the brain, small intestine and adrenal cortex. They contain peroxide-producing enzymes and peroxide-destroying enzymes. Oxidases catalyze the oxidation of substrates producing hydrogen peroxide. Hydrogen peroxide is produced by the cell’s biochemical machinery to attack and kill ingested bacteria. However hydrogen peroxide is harmful to living cells. In plants peroxisomes are present in the mesophyll cells.
So, the correct answer is “Option D”.

Note: Peroxisomes are a type of microbodies. The microbodies are minute, simple, roughly spherical sacs that are bounded by a single unit membrane. They usually lie near the endoplasmic reticulum, or plastids or both.