Most people picture molecules as rigid, locked-together structures — like tiny pieces of stone. But the molecules inside every living cell are something far more remarkable: they hold together loosely and temporarily on purpose. The strongest molecular bonds — called covalent bonds — share electrons so firmly that breaking them requires a serious chemical event. These strong bonds produce the stable structures of large molecules like DNA, RNA, lipids, and proteins. When the D

Alternative splicing of messenger RNA has been shown to be critical for the development of the human brain. The ability to make many new and complex proteins allowed the development of the enormous molecular complexity in different neurons and in different regions. For some reason, in evolution humans developed the ability to use alternative splicing much more than other species. This ability is most prominent in the brain. This post updates the most recent understanding of h

There are 20,000 “genes” but more than 100,000 different proteins. Alternative RNA editing is necessary to form the many different patterns.In the fly, one gene has 38,000 alternative patterns. (picture below)In humans, one gene can have 500 alternative patterns. Alternative RNA splicing in evolution is one of the critical factors in the development of the complexity of human beings Previous posts have shown how the shapes of complex interlocking proteins allow the neuron mac

Some think viruses are not alive. It is, therefore, very surprising that they can evade elaborate cellular mechanisms used to find and destroy them. Search and destroy mechanisms of the cell and counter attacks from viruses are very complex. Cells use many sensors to find DNA and RNA that is not where it is supposed to be. When found, other mechanisms are triggered to get rid of it. Major cellular tools are pattern recognition receptors with enormous numbers of variations all

Only a very small percentage of the world’s microbes have been discovered, and even less of the much more plentiful and diverse viruses. So, it is not surprising that many dramatic new viruses have recently been found that alter our understanding of evolution. The giant Pandora viruses and many new unique ocean phages have brought forth questions about the validity of the current three-limbed diagram of the tree of life (archaea, bacteria, eukarya). With viruses and virus lik

50% of the human genome consists of jumping genes or mobile genetic elements. The 8% of human DNA from retroviruses has been vital to human evolution, such as determining the human placenta, epigenetic changes in the brain and digestive enzymes. An epigenetic immune system in the nucleus battles the jumping genes for control of the cell and control of evolution. Jumping genes, being large strands of DNA with specific functions, are much more likely to be the drivers of evol

The regulation of DNA is fantastically complex with many different layers: changing 3D shapes of the chromatin and loops of DNA; regional differences in nuclear DNA; large numbers of different epigenetic tags on DNA nucleotides and protective protein histone molecules; complex DNA repair mechanisms and alternative messenger RNA splicing; hundreds of thousands of transcription factors; and many different kinds of small and large RNAs that influence every aspect of the process.

A previous post noted how microbes can help cancers in all stages of their development. Now, it has been found that the one-time microbe now the mitochondria is also vital for cancer to start, to grow, to survive and to metastasize. These microbes and the mitochondria use back and forth communication to help cancers in many ways. This post describes the recent research about mitochondria and its vital relationship to cancer. Mitochondria Joined Forces With Our Cells Two billi

Communication among cells is the basis of all immune and nervous system activity. Research continues to find large vocabularies of signals in different languages—neurotransmitters, cytokines, small RNAs, protein transcription factors, small lipid molecules and glycan sugars. The numbers of signals is growing fantastically with at least 50 neurotransmitters, 100 cytokines, thousands of transcription factors and small RNAs and as yet indefinable large number of ubiquitin tags,