Enz

The Enz is a river flowing north from the Black Forest to the Neckar in Baden-Württemberg. It is 112 km long.

Its headstreams – the Little Enz (German: Kleine Enz) and the Great Enz or Big Enz (Große Enz) – rise in the Northern Black Forest, the latter at Enzklösterle. In Calmbach, the Little Enz and the Big Enz join to form the Enz. The river passes through Neuenbürg and Pforzheim, where it leaves the Black Forest. It then flows through the cities of Vaihingen and Bietigheim-Bissingen. Along the lower course, wine is grown.

Major tributaries to the Enz are Glems and Nagold (with its tributary Würm). Near Besigheim the Enz feeds into the Neckar.

In earlier times the Enz was important for the timber rafting industry.

Geography

River system

The Enz flows through two large natural regions: in the upper half of its course, the river and its tributaries drain the eastern half of the Northern Black Forest; later it flows through the southwest German Gäu landscape, mostly through the Neckar Basin.

Enzkreis

Enzkreis is a district (Kreis) in the north-west of Baden-Württemberg, Germany. Neighboring districts are (from west clockwise) Karlsruhe, Heilbronn, Ludwigsburg, Böblingen and Calw. The district-free Pforzheim area in the south is nearly completely surrounded by Enz.

History

The district was created in 1973, when the previous district Pforzheim was merged with parts of the neighboring districts Vaihingen, Leonberg and Calw. Some part of the district Pforzheim was included into the city Pforzheim.

The district Pforzheim dates back to 1939, when the Bezirksamt Pforzheim was split into the district and the district-free city.

Geography

The south of the Enz district covers the northern part of the Black Forest. In the north-west of the district is the Kraichgau, a mainly agricultural area. The main river is the Enz, a tributary of the Neckar.

International relations

Twin towns — Sister cities

Since March 1993 the district has an official partnership with the Italian province Reggio Emilia. Since 1996 the district has a partnership with the Polish city Mysłowice. As two municipalities left the city in a communal reform in 1995, the partnership also includes Imielin and Chelm Slaski. In March 2001 the Enz district together with the city Pforzheim started a friendship with the Hungarian Komitat Györ-Moson-Sopron.

Enzyme

Enzymes /ˈɛnzaɪmz/ are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions. The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life. The set of enzymes made in a cell determines which metabolic pathways occur in that cell. The study of enzymes is called enzymology.

Enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins, although a few are catalytic RNA molecules. Enzymes' specificity comes from their unique three-dimensional structures.

Like all catalysts, enzymes increase the rate of a reaction by lowering its activation energy. Some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5'-phosphate decarboxylase, which allows a reaction that would otherwise take millions of years to occur in milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, nor do they alter the equilibrium of a reaction. Enzymes differ from most other catalysts by being much more specific. Enzyme activity can be affected by other molecules: inhibitors are molecules that decrease enzyme activity, and activators are molecules that increase activity. Many drugs and poisons are enzyme inhibitors. An enzyme's activity decreases markedly outside its optimal temperature and pH.