Lysis

Lysis (/ˈlaɪsɪs/, LEYE-sis; Greek λύσις lýsis, "a loosing" from λύειν lýein, "to unbind") refers to the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" /ˈlɪtɪk/, LI-tik) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a lysate. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles.

Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells.Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If cell wall is completely lost, the bacterium is referred as a protoplast if penicillin was used on gram-positive bacteria, and spheroplast when used on gram-negative bacteria.

Lysis (dialogue)

Lysis (/ˈlaɪsɪs/; Greek: Λύσις) is a dialogue of Plato which discusses the nature of friendship. It is generally classified as an early dialogue.

The main characters are Socrates, the boys Lysis and Menexenus who are friends, as well as Hippothales, who is in unrequited love with Lysis and therefore, after the initial conversation, hides himself behind the surrounding listeners. Socrates proposes four possible notions regarding the true nature of friendship:

Of all those options, Socrates thinks that the only logical possibility is the friendship between men who are good and men who are neither good nor bad.

In the end, Socrates seems to discard all these ideas as wrong, although his para-logical refutations have strong hints of irony about them.

Lysis (disambiguation)

Lysis can refer to: