Glutathione (GSH) is a tripeptide with an unusual peptide linkage between the amine group of cysteine (which is attached by normal peptide linkage to a glycine) and the carboxyl group of the glutamate side-chain. It is an antioxidant, preventing damage to important cellular components caused by reactive oxygen species such as free radicals and peroxides.

Thiol groups are reducing agents, existing at a concentration of approximately 5 mM in animal cells. Glutathione reduces disulfide bonds formed within cytoplasmic proteins to cysteines by serving as an electron donor. In the process, glutathione is converted to its oxidized form glutathione disulfide (GSSG), also called L(-)-Glutathione.

Once oxidized, glutathione can be reduced back by glutathione reductase, using NADPH as an electron donor. The ratio of reduced glutathione to oxidized glutathione within cells is often used as a measure of cellular toxicity.

Glutathione is not an essential nutrient (meaning it does not have to be obtained via food), since it can be synthesized in the body from the amino acids L-cysteine, L-glutamic acid, and glycine. The sulfhydryl (thiol) group (SH) of cysteine serves as a proton donor and is responsible for the biological activity of glutathione. Cysteine is the rate-limiting factor in cellular glutathione synthesis, since this amino acid is relatively rare in foodstuffs.

Robert Keller (1828-1891) was a German music editor.

Keller was born on January 6, 1828 in Harpersdorf in Lower Silesia. He moved to Berlin where he became a musical editor for the music publishing company N. Simrock. Keller edited and arranged a substantial amount of works by Johannes Brahms and Antonín Dvořák.

Suzanne Somers (born as Suzanne Marie Mahoney on October 16, 1946) is an American actress, author, singer and businesswoman, known for her television roles as Chrissy Snow on Three's Company and as Carol Lambert on Step by Step.

Somers later became the author of a series of best-selling self-help books, including Ageless: The Naked Truth About Bioidentical Hormones (2006), a book about bioidentical hormone replacement therapy. She has also released two autobiographies, four diet books, and a book of poetry entitled "Touch Me" (1980). She currently features items of her design on ShopNBC.^{[citation needed]}

She is criticized for her views on some medical subjects and her advocacy of the Wiley Protocol, which has been labelled as "scientifically unproven and dangerous". Her promotion of alternative cancer treatments has received criticism from the American Cancer Society.

Born Suzanne Marie Mahoney in San Bruno, California, Somers was the third of four children in an Irish Catholic family. Her mother, Marion Elizabeth (née Turner), was a medical secretary, and her father, Francis Mahoney, was a laborer (loading beer into boxcars) and gardener. Her family attended church at St. Robert's Catholic Church in San Bruno.