1 Pepsin is the main gastric enzyme. 2  It is produced by the stomach cells called chief cells in its inactive form pepsinogen, which is a zymogen. 3  Pepsinogen is then activated by the stomach acid into its active form, pepsin.
Single (music) In music, a single, record single or music single is a type of release, typically a song recording of fewer tracks than an LP record, an album or an EP record. This can be released for sale to the public in a variety of different formats. In most cases, a single is a song that is released separately from an album, although it usually also appears on an album. Typically, these are the songs from albums that are released separately for promotional uses such as digital download or commercial radio
Although Let It Be was the final album that the Beatles completed before the band's dissolution in April 1970, most of the album had been recorded before the Abbey Road sessions began. A double A-side single from the album, Something/Come Together, released in October, topped the Billboard chart in the US. Abbey Road is a rock album that incorporates genres such as blues, pop and progressive rock, and it makes prominent use of the Moog synthesizer and the Leslie speaker.