Nicotinamide adenine dinucleotide (NAD+) is a coenzyme found in all
living cells. The compound is a dinucleotide, since it consists of two
nucleotides joined through their phosphate groups, with one nucleotide
containing an adenine base and the other containing nicotinamide. In
metabolism, NAD+ is involved in redox reactions, carrying electrons
from one reaction to another. The coenzyme is therefore found in two
forms in cells: NAD+ is an oxidizing agent – it accepts electrons from
other molecules and becomes reduced. However, it is also used in other
cellular processes, notably as a substrate of enzymes that add or
remove chemical groups from proteins, in posttranslational
modifications. Due to the importance of these functions, the enzymes
involved in NAD+ metabolism are targets for drug discovery. In
organisms, NAD+ can be synthesized from basic building blocks (de novo)
from the amino acids tryptophan or aspartic acid. Some NAD+ is also
converted into nicotinamide adenine dinucleotide phosphate (NADP+); the
chemistry of this related coenzyme is similar to that of NAD+, but it
has different roles in metabolism.
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Today's selected anniversaries:
An expedition led by James Cook reached Maui, the second largest of the
The University of Notre Dame in South Bend, Indiana, USA, was founded
as an all-male institution by members of the Roman Catholic
Congregation of Holy Cross.
Unable to resolve disputes with Eddie Livingstone, owner of the Toronto
Blueshirts, the other ice hockey clubs of Canada's National Hockey
Association officially agreed to leave that sports league and to form a
new one: the National Hockey League.
The Soviet Red Army shelled Mainila, and then claimed that the fire
originated from Finland across a nearby border, giving them a casus
belli to launch the the Winter War a few days later..
World War II: Josip Broz Tito and the Yugoslav Partisans convened the
first meeting of the Anti-Fascist Council of National Liberation of
Yugoslavia at Bihać in northwestern Bosnia.
Wiktionary's word of the day:
(biology, paleontology) Having a distinct edge; bordered
Wikiquote quote of the day:
Knowledge is proud that he has learned so much;
Wisdom is humble that he knows no more.