Difference Between Lysosome and Peroxisome

Main Difference

The main difference between lysosomes and peroxisomes is that lysosome consists of degradative enzymes, which break down about all the biological polymers within the cell whereas peroxisome consists of enzymes, which are responsible for oxidation reactions and break down of metabolic hydrogen peroxide.

Lysosome vs. Peroxisome

Lysosome and peroxisome are two distinctive types of single-membrane compartments found inside the cell. Lysosomes are present only in animals whereas peroxisomes are found in all eukaryotes. Lysosomes are larger whereas peroxisomes are comparatively small. Both lysosomes and peroxisomes are enzyme compartments. The most important difference between lysosome and peroxisome is that lysosome contains a set of degradative enzymes, which break down about all the biological polymers within the cell while peroxisome consists of enzymes, which are responsible for the oxidation reactions and break down of metabolic hydrogen peroxide. The most important characteristic of peroxisomes is fatty acid metabolism. They are thus different from lysosomes in that they are concerned with metabolism instead of maintenance of the cell. Lysosomes generate from endosomes that bud off from the Golgi apparatus. The endosomes are packed with hydrolytic enzymes, which form them lysosomes. Peroxisomes do not develop from endosomes; they are created from different proteins (or polypeptide chains) synthesized in the cell by ribosomes. Lysosomes are responsible for digestion in the cells while peroxisomes are responsible for the protection of the cell against metabolic hydrogen peroxide.

Comparison Chart

LysosomePeroxisome
A lysosome is a membrane-bounded organelle present within the animal cell, which consists of enzymes for the digestion of biological polymers like proteins, polysaccharides, lipids, and nucleic acids.A peroxisome is a bounded membrane organelle present in all eukaryotes, containing enzymes for the degradation of metabolic hydrogen peroxides.
Composition
Lysosomes are composed of degradative enzymes.Peroxisomes are composed of oxidative enzymes.
Function
The function of lysosomes is the digestion of biomolecules and other unwanted material in the cell.The function of peroxisomes is the protection of the cell against metabolic hydrogen peroxide.
Presence
Lysosomes are present only in animals.Peroxisomes are present in all eukaryotes.
Size
Lysosomes are comparatively large.Peroxisomes are small in size.
Signal Sequence of the Target Proteins
The proteins present in the lysosomes are tagged with mannose 6-phosphate.The proteins present in the peroxisomes are tagged with peroxisomal targeting signal (PTS)
Energy Generation
Degradative reactions occurring in the lysosomes do not generate energy.Oxidative reactions take place in peroxisomes generate ATP energy.
Other Functions
The other functions of lysosomes are endocytosis, autophagy, and phagocytosis.Peroxisomes are involved in the biosynthesis of lipids and photorespiration.

What is Lysosome?

Lysosomes are membrane-enclosed organelles which consist of enzymes which can degrade all types of biological polymers like proteins, nucleic acids, carbohydrates, and lipids. Lysosomes are known as the scavengers of the cell; they keep cells clean of debris and unwanted metabolites. Lysosomes made up from endosomes that bud off from the Golgi apparatus. The endosomes are covered with hydrolytic enzymes that make them lysosomes. All of the lysosomal enzymes are acid hydrolases, which are active at the acidic pH (about 5) which is maintained inside the lysosomes but not at the neutral pH (about 7.2) characteristic of the rest of the cytoplasm. Lysosomes contain various lytic enzymes which help in the breakdown of unwanted materials in the cell, i.e., old organelles, pathogens, bacteria, etc. Lysosomes also play a major role in the digestion of the material taken up from outside the cells by the process of endocytosis. The general way in which lysosomes operate is: they fuse with ‘containers’ called vacuoles and release their contents within the vacuoles. The enzymes then digest and degrade whatever is present inside the vacuoles. The reason is that if all the enzymes contained within lysosomes were spilled inside the cell into its cytoplasm, they would end up degrading the cell itself! Lysosomes, therefore, have a job with great responsibility, as must be evident.

What is Peroxisome?

Peroxisomes are small; membrane-bounded organelles that consist of enzymes involved in a variety of metabolic reactions, including various aspects of energy metabolism. Peroxisomes are similar to lysosomes in shape, the reason why many people confuse between the two. Peroxisomes are assembled, like mitochondria and chloroplasts, from different proteins that are synthesized in the cell on free ribosomes and then imported into peroxisomes as completed polypeptide chains. Although peroxisomes do not contain their genomes, they are similar to mitochondria and chloroplasts in that they replicate by division. Peroxisomes contain about 50 different enzymes, which are involved in a variety of biochemical pathways in different types of cells. Peroxisomes initially were defined as organelles that perform oxidation reactions leading to the production of hydrogen peroxide. Since hydrogen peroxide is destructive to the cell, peroxisomes also contain the enzyme catalase, which degrades hydrogen peroxide either by converting it to less harmful substances like water or by using it to oxidize other organic compounds. A large number of substrates are broken down by such oxidative reactions in peroxisomes, for example, uric acid, amino acids, and fatty acids. The oxidation of fatty acids is a particularly important example because it provides the main cause of metabolic energy. In animal cells, fatty acids are oxidized in both peroxisomes and mitochondria; however, in yeasts and plants, fatty acid oxidation is limited to peroxisomes.

Peroxisomes play particularly important roles in plants. Peroxisomes in seeds are responsible for the break down of stored fatty acids to carbohydrates, which is very important to providing energy and raw materials for the growth of the new budding plant to grow as the seed germinates. This process occurs using a series of reactions termed the glyoxylate cycle, which is a variant of the Calvin cycle. The peroxisomes in which this process takes place are sometimes called glyoxysomes. Peroxisomes present in leaves are involved in the process of photorespiration and they are used to metabolize a side product formed during photosynthesis.

Key Differences

  1. Lysosomes degrade biological polymers like proteins and polysaccharides whereas peroxisomes oxidize organic compounds, breaking down metabolic hydrogen peroxides.
  2. Lysosomes are only found in animals while peroxisomes are found in all eukaryotes.
  3. Lysosomes are originated from Golgi apparatus or endoplasmic reticulum, on the other hand, peroxisomes are derived from the endoplasmic reticulum, and they can replicate by themselves.
  4. Lysosomes are comparatively large conversely peroxisomes are small.
  5. The function of lysosomes is the digestion in the cell whereas peroxisomes are responsible for the protection of the cell against metabolic hydrogen peroxide.
  6. Lysosomes consist of degradative enzymes, on the flip side, Peroxisomes consist of oxidative enzymes.

Comparison Video

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Conclusion

Lysosome and peroxisome are two organelles, which contain enzymes that catalyze a variety of biochemical processes in the cell. The difference lies in the enzymes they contain and their functions.

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