The gel-like material within the cell membrane is referred to as the cytoplasm. It is a fluid matrix, the cytosol, which consists of 80% to 90% water, salts, organic molecules and many enzymes that catalyze reactions, along with dissolved substances such as proteins and nutrients.
The River Thames is the second longest river in the United Kingdom and the longest river entirely in England, rising at Thames Head in Gloucestershire, and flowing into the North Sea at the Thames Estuary.
The most important river entering the Black Sea is the Danube. The Black Sea has an area of 422,000 kmÂ² and a maximum depth of 2210 m. Countries bordering on the Black Sea are Turkey, Bulgaria, Romania, Ukraine, Russia, and Georgia (including the breakaway region of Abkhazia). The Crimean peninsula is a Ukrainian autonomous republic.