Engineering

Getting smart about off-grid desalination

Small changes in membrane design can have a large impact on the performance of a new technology developed at KAUST that uses waste heat from solar cells for seawater desalination.

Energy & Green Tech

Printing perovskite solar cells

To reach the target of carbon neutral, a transition from fossil energy to renewable energy generation is indispensable. Photovoltaic technology is considered as one of the most prominent sources of renewable energy. For decades, ...

Energy & Green Tech

Removing the lead hazard from perovskite solar cells

Although they offer a very promising solution for capturing solar energy, perovskite solar cells contain lead, which is toxic to the environment and a serious health hazard. EPFL scientists have now found a very elegant and ...

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Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.

This text uses material from Wikipedia, licensed under CC BY-SA