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(cell and molecular biology)
A specialized subcellular structure, such as a mitochondrion, having a special function; a condensed system showing a high degree of internal order and definite limits of size and shape.



a part of the body of a unicellular organism, or protozoan, that performs any one of various functions. Organelles are especially diverse and complex in Infusoria and Flagellata. There are several types of organelles. Skeletal and support organelles protect the organism from mechanical, chemical, and other harmful effects (for example, the shells of Sarcodina and Infusoria). There also are locomotor and contractile organelles (for example, flagella, cilia, and myonemes); sensory, or receptor, organelles (for example, photosensitive ocelli); and attack and defense organelles (for example, in Infusoria, the rod-shaped formations known as trichocysts, which are discharged from the body). Digestive organelles capture, conduct, and digest the food (for example, the digestive vacuoles of Infusoria). There are also excretory and secretory organelles (for example, the pulsating vacuoles of Infusoria). The term “organelle” is often used as a synonym for “organoid.”

References in periodicals archive ?
15) However, it proved very difficult to study the cellular and molecular mechanisms of organelle division in eukaryotes for the following reasons.
Scientists at The Rockefeller University have discovered that it depends on whether tiny organ-like structures known as organelles are allocated properly within the dividing stem cell.
Biologists and biology educators face this issue when communicating about any sort of biological structure, from organelles to whole organisms.
Finally, this finding implies that organelle breakdown may occur through multiple independent pathways, so researchers' understanding of the mechanism of this pathway in apoptosis is not comprehensive yet.
But the new pictures showed that the roots continue through, make a sharp 110-degree angle, and extend all the way to the membrane at the opposite side of the cell, where they connect with the striated organelle.
The nucleus is a fairly conspicuous organelle within the plant cells.
There was no evidence of adjacent organelle lysis or of agglomeration of particulates (Figure 4).
The vaccine is designed to ferry the papillomavirus to an internal organelle, called a lysosome, where the protein is broken into bits and sent to the cell surface for display.
Hepatic iron toxicity because of iron overload seems to be mediated by lipid peroxidation of biological membranes and the associated organelle dysfunctions.
Molecules that are to be broken down are enclosed in a membrane sack that forms an organelle called an autophagosome.
Having students argue why a particular organelle is the best one in the cell is an amusing activity that covers a lot of factual information about cell structure and function.