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Moment of truth
The fastest man-made object that ever leave the Earth is the New Horizon spacecraft, launched in January 2006, and attained a speed of more than 36000 mph.

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lye Chem.
Strong solution of sodium or potassium hydroxide, which can be obtained by leaching wood ashes and use in soap making and textile.

lyophilic Chem.
Of a substance (such as colloid) having an affinity for a solvent (solvent-loving). The substance can be a solid that interacts and subsequently dispersed in the solvent. For instance, clay is a lyophilic colloid disperse in water. There are some special terms for certain solvents. For instance, substance that have affinity with water is hydrophilic; with oil is lipophilic and with other organic liquids is organophilic.

lyophobic Chem.
Of a substance that lacking any affinity for a solvent (solvent-hating). For instance, clay is lyophobic to oil. Colloid molecules when dispersed in water will aggregate such that the lyophobic group (of atoms) is interacting with one another and avoid interactions with the water molecules. Such group is called hydrophobic (water-hating). Substance that avoids oil is called lipophobic.

lysate Biol.
A fluid containing the content of lysed cells. See also lysis.

lysis Biol.
Derived from Greek word, meaning to separate. It is breaking of a biological cell, by viral, enzymic or osmotic means. Lysozyme, an enzyme found in animal saliva, can breakdown many species of bacteria. Lysis of cell via osmotic mechanism involves movement of excessive water into cell such that the cell membrane cannot withstand the build up of osmotic pressure of the water inside, leading to bursting of cell. This process is also called cytolysis and usually occur in a hypotonic environment.

lysosome Biol.
An organelle located within a living cell that contained digestive protein enzymes. Lysosome is responsible for removing damaged or excess cellular products. It also digests viruses or bacteria. A typical lysosome appears spherical or elongated bounded by a membrane. It measures about 0.1-1 micrometer in size. The membrane acts as a barrier that prevents the digestive enzymes contained within the lysosome from destroying other parts of the cell. A lysosome can contain up to several dozen of digestive enzymes each is capable to digest different types of foreign substances and cellular species.

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