written by: Emma Lloyd•edited by: Paul Arnold•updated: 10/21/2011
Venture deep inside the nucleus to explore the structure and function of DNA. The molecule's structure is key to its function and replication, and it controls its own replication and transcription in a way that is both simple and highly complicated.
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DNA: The Molecule Life
DNA is the hereditary material in most organisms including humans. Since the moment its structure was worked out in 1953 our knowledge of the molecule of life has come a long, long way.
Bookmark this guide to DNA and return to it time and again when you need to top up your knowledge of the double helix.
DNA is the acronym for deoxyribonucleic acid. A bit of a mouthful, but what does it actually mean, anyway? Breaking the word into its constituent parts reveals the different molecules from which DNA is made. In this article you'll learn about these different molecules and how they combine to form DNA’s unique structure.
Most of the DNA in a human cell is found in the nucleus, but DNA is also located in the mitochondria of the cell. In other cell types, such as viruses and bacteria, DNA is “packaged" differently to reflect the different needs of those organisms.
There is plenty more to learn about the structure of DNA, and there are many interesting facts to be found in these articles. DNA’s unique structure is key to the way in which it reproduces itself, and in the way individual genes code for proteins.
Within the DNA macromolecule are various types of smaller ones, including the deoxyribose sugar, phosphate groups, and the four nitrogenous bases. Incredibly, it’s these four bases—just four molecules—that code for all the proteins produced by the genome.
DNA function is critical to life, and DNA structure is critical to its function. One of the important factors that helps to maintain DNA structure is the nature of its hydrogen bonds. These bonds are crucial to the stability of the DNA molecule, and there are both internal and external hydrogen bonds present in DNA.
Every aspect of DNA structure serves a purpose, even though it’s not always apparent. One of the key features of the DNA molecule is that its two complimentary strands are arranged in an anti-parallel fashion, meaning that the strands run in opposite directions.
There are a staggering six billion base pairs in the human genome, and in relation to the size of a human cell, that’s a hugely long structure to fit into the small space the nucleus provides. The 46 chromosomes of the human genome are able to fit into a space that is millions of times smaller than their length. How on earth is such a feat achieved?
DNA isn’t the only nucleic acid present in cells: there are also ribonucleic acids, known as RNA. These two types of nucleic acids interact to produce proteins. Genes are sections of DNA that code for proteins, but how does a linear section of DNA code for a three-dimensional protein? In these articles you'll learn about how DNA and RNA interact to produce proteins.
There are thousands of genes in the human genome, but they don’t need to be active at all times. How does DNA “decide" when genes should be switched on to make the proteins they code for? In this article you'll discover the different ways in which DNA controls its own gene expression.
The process by which DNA reproduces itself is called replication. During DNA replication the two strands of a single DNA molecule unwind and become the templates for two new double-stranded DNA molecules. This ensures that both new double-stranded molecules are exact replicas of the original. Learn more about DNA replication, and how RNA is involved.
Unfortunately, DNA replication is not a fool-proof process. For various reasons, errors can crop up. Sometimes these errors don’t make any difference in the way the genome functions, and sometimes the errors can be repaired. In some cases, however, a replication error can give rise to a genetic disease.
Two of the most important moments in the history of genetics are the discovery of DNA and later the elucidation of its structure. DNA was discovered by Oswald Avery, and James Watson and Francis Crick used work by Maurice Wilkins and Rosalind Franklin to determine the structure of the molecule.
This is a compilation of articles contained on the Bright Hub site. References and resources used by the authors to create each piece of content within the compilation can be found on the individual articles themselves.