2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog is about the various uses of nitrogen.
Nitrogen – an imperative part of DNA
The polymer that makes up the genetic code of is a sequence of nitrogen bases laid out on a backbone of sugar and phosphate molecules and blended into a double helix.
The nitrogen bases are translated into proteins and enzymes which regulate most our system’s biochemical reactions.
RDX is a nitrogen explosive. This means its explosive properties are primarily caused by the presence of many nitrogen–nitrogen bonds, which are extremely unstable, especially as nitrogen atoms want to come together to produce nitrogen gas due to the triple bond.
Ultimately, the more nitrogen–nitrogen bonds a molecule has, the more explosive it is. RDX is normally combined with other chemicals to make it less sensitive or less likely to explode.
One of the most powerful explosive chemicals is PETN, containing nitro groups and nitroglycerin in dynamite. Despite its powerful explosions, the chemical rarely will detonate alone. PETN was used frequently during World War II, whereby PETN was used to create exploding bridgewire detonators, using electric currents for detonations.
Among the least stable explosives is aziroazide azide, with 14 unstable nitrogen bonds, most of them bonded into unstable nitrogen–nitrogen bonds. Touching or handling this chemical can cause it to detonate, making it one of the most dangerous non-nuclear chemicals.
Nitrogen and plants
Nitrogen plays a significant role for plants to keep healthy. Plants usually contain 3-4% nitrogen in their above-ground tissues. Nitrogen is a major component of chlorophyll which plants use to capture sunlight energy to produce sugars, and a major component of amino acids, which are the building blocks of life.
Overall, nitrogen is a significant component to DNA, a key nutrient to plants, and the uses of nitrogen in everyday life span across various chemical industries including the production of fertilisers and explosives.
Organised by the National Human Genome Research Institute each year, National DNA Day in the US on 25 April celebrates the discovery of DNA’s double helix in 1953 and the completion of the Human Genome Project in 2003. Here, we explore the history of DNA and its discovery’s unparalleled effect on science, medicine and the way we now understand the human body.
Discovering DNA’s structure
Using the pictures that she had taken, Franklin was able to calculate the dimensions of the strands and found the phosphates were on the outside of the DNA helix.
Rosalind Franklin working in her lab. Image: Wikimedia Commons
Meanwhile, at the University of Cambridge, James Watson and Francis Crick deduced the double-helix structure of DNA, describing it as ‘two helical chains each coiled round the same axis’ following a right-handed helix containing phosphate diester groups joining β-D-deoxyribofuranose residues with 3’,5’ linkages.
The discoveries made by these scientists would propel the study of genetics into the modern science we know today. Crick and Watson were awarded the Nobel Prize for Physiology or Medicine alongside Maurice Wilkins, who worked with Rosalind Franklin, in 1962. You can read their original paper here.
Dolly the sheep
Dolly on display at the National Museum of Scotland, UK.
Dolly is arguably the most famous sheep in the world, having been the first mammal to be cloned from an adult cell. Born in 1996, Dolly was part of a series of experiments at the Roslin Institute in Edinburgh to create GM livestock that could be used in scientific experiments.
She was cloned using a technique called somatic cell nuclear transfer, where a cell nucleus from one adult is transferred into an unfertilised developing egg cell of another that has had its nucleus removed, which is then implanted into a surrogate mother.
The scientific legacy of Dolly the sheep. Video: Al Jazeera English
Dolly lived until 2003 when she was euthanised after contracting a form of lung cancer. Many speculated that Dolly’s early death was related to the cloning experiment but extensive health screening throughout Dolly’s life by the Roslin Institute suggest otherwise.
Her creation has led to further cloning projects and could be used in the future to preserve the populations of endangered or extinct species, and has led to significant developments in stem cell research.
In 2009, Spanish researchers announced the cloning of a Pyrenean ibex, which has been extinct since 2000, and was the first cloning of an extinct animal. Unfortunately, the ibex died shortly after birth but there have been a few successful stories since then.
The Human Genome Project
Beginning in 1990 and finishing in 2003, the Human Genome Project was an international research initiative that aimed to write the entire sequence of nucleotide base pairs that make up the human genome, including the mapping of all its genes that determine our physical and functional attributes.
The publicly funded $3bn project was able to map 99% of the human genome with 99.99% accuracy, which included its 3.2bn Mega-base pairs, 20,000 genes and 23 chromosome pairs, and has led to advancements in bioinformatics, personalised medicine and a deeper understanding of human evolution.
In honour of World Health Day, held on 7 April 2019 annually, we have collated the five most innovative healthcare projects we have featured on SCI’s website over the past year.
Using 2D imaging techniques to diagnose problems with the heart can be challenging due to the constant movement of the cardiac system. Currently, when a patient undergoes a cardiac MRI scan they have to hold their breath while the scan takes snapshots in time with their heartbeat.
Still images are difficult to obtain with this traditional technique as a beating heart and blood flow can blur the picture. This method becomes trickier if the individual has existing breathing problems or an irregular heartbeat.
An innovative new screening method using cell aggregates shaped like spheres may lead to the discovery of smarter cancer drugs, a team from the Scripps Research Institute, California, US, has reported.
The 3D aggregates, called spheroids, can be used to obtain data from potentially thousands of compounds using high throughput screening (HTS). HTS can quickly identify active compounds and genes in a specific biomolecular pathway using robotics and data processing.
Several thousand antibiotic combinations have been found to be more effective in treating bacterial infections than first thought.
Antibiotic combination therapies are usually avoided when treating bacterial infections, with scientists believing combinations are likely to reduce the efficacy of the drugs used. Now, a group at UCLA, USA, have identified over 8,000 antibiotic combinations that work more effectively than predicted.
Researchers at the University of Copenhagen, Denmark, have identified a mechanism that prevents natural DNA errors in our cells. These errors can lead to permanent damage to our genetic code and potentially diseases such as cancer.
Mutations occurring in human DNA can lead to fatal diseases like cancer. It is well documented that DNA-damaging processes, such as smoking tobacco or being exposed to high levels of ultraviolet (UV) light through sunburn, can lead to increased risk of developing certain forms of cancer.
Treatments for Alzheimer’s disease can be expensive to produce, but by using novel cultivation of daffodils one small Welsh company has managed to find a cost-effective production method of one pharmaceutical drug, galanthamine.
Alzheimer’s disease is a neurodegenerative disease with a range of symptoms, including language problems, memory loss, disorientation and mood swings. Despite this, the cause of Alzheimer’s is very understood. The Alzheimer’s disease drug market is currently worth an estimated US$8bn.