Health

Body building supplement could be bad for the brain

People taking the protein supplement L-norvaline should be aware of its potential for harm, scientists say. L-norvaline is an ingredient widely used in body building supplements and is promoted as a compound that can boost ...

Immunology

Researchers discover how sleep can fight infection

Researchers in Germany have discovered why sleep can sometimes be the best medicine. Sleep improves the potential ability of some of the body's immune cells to attach to their targets, according to a new study that will be ...

Medical research

CRISPR gene editing makes stem cells 'invisible' to immune system

UC San Francisco scientists have used the CRISPR-Cas9 gene-editing system to create the first pluripotent stem cells that are functionally "invisible" to the immune system, a feat of biological engineering that, in laboratory ...

Immunology

Masterswitch discovered in body's immune system

Scientists have discovered a critical part of the body's immune system with potentially major implications for the treatment of some of the most devastating diseases affecting humans.

Cancer

Immune stimulant molecule shown to prevent cancer

A research team at the University of Louisville has discovered that an immune checkpoint molecule they developed for cancer immunotherapy, also protects against future development of multiple types of cancer when administered ...

Immunology

Patients' own cells could be the key to treating Crohn's disease

A new technique using patients' own modified cells to treat Crohn's disease has been proven to be effective in experiments using human cells, with a clinical trial of the treatment expected to start in the next six months.

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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.

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