The physics of sperm vs. the physics of sperm whales - Aatish Bhatia Fractal Globules in DNA : FractalFoundation.org Researchers have discovered how the DNA is packed into our cells in such a way that the roughly 2 meters of DNA in each cell doesn’t tangle, and is easily accessible when it’s needed to make proteins. And the key is: Fractal Geometry! ‘…Researchers found that the genome has a highly organized structure. Fractal folding keeps DNA organized in a cell's nucleus, despite the tight pack. Read more details at Science News.
Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope. To see anything smaller than 500 nm, you will need an electron microscope. Adenine The label on the nucleotide is not quite accurate. How can an X chromosome be nearly as big as the head of the sperm cell? No, this isn't a mistake. The X chromosome is shown here in a condensed state, as it would appear in a cell that's going through mitosis. A chromosome is made up of genetic material (one long piece of DNA) wrapped around structural support proteins (histones). Carbon The size of the carbon atom is based on its van der Waals radius.
Translation Molecular Expressions Cell Biology: Structure of Cells and Viruses Introduction to Cell and Virus Structure At first glance, the petal of a flower or the skin on the back of a human hand may seem smooth and seamless, as if they were composed of a single, indistinct substance. In reality, however, many tiny individual units called cells make up these objects and almost all other components of plants and animals. The average human body contains over 75 trillion cells, but many life forms exist as single cells that perform all the functions necessary for independent existence. Most cells are far too small to be seen with the naked eye and require the use of high-power optical and electron microscopes for careful examination. The relative scale of biological organisms as well as the useful range of several different detection devices are illustrated in Figure 1. Yet, until the mid-seventeenth century, scientists were unaware that cells even existed. Questions or comments? Last modification: Thursday, May 12, 2005 at 11:18 AM Microscopes provided by:
Protein Synthesis The Cell and its Organelles Lists of Nobel Prizes and Laureates The Cell and its Organelles Play the Incredible Megacell Game About the game An ultracentrifuge is used for separating the organelles in the cell according to their size, shape and density. The Nobel Prize The 1974 Nobel Laureates in Physiology or Medicine developed methods that made it possible to see and identify organelles, the specialised compartments inside all our cells.Read More » Share this: Share on facebook Share on google_plusone_share Share on twitter More Sharing Services Share on email To cite this pageMLA style: "The Cell and its Organelles". Recommended: The Legacy of Alfred Nobel On 27 November 1895 Alfred Nobel signed his last will in Paris. Play the Blood Typing Game Try to save some patients and learn about human blood types! Unlocking the Secrets of Our Cells Discover the 2012 awarded research on stem cells and cell signalling. Contact E-mail us Press Sitemap A-Z Index Frequently Asked Questions Terms Follow Contact | Press | Sitemap | FAQ | Terms
Mitochondria Research Cell biology Understanding cells in terms of their molecular components. Knowing the components of cells and how cells work is fundamental to all biological sciences. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology as well as to biomedical fields such as cancer research and developmental biology. These fundamental similarities and differences provide a unifying theme, sometimes allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types. Therefore, research in cell biology is closely related to genetics, biochemistry, molecular biology, immunology, and developmental biology. Processes Movement of proteins Endothelial cells under the microscope. Each type of protein is usually sent to a particular part of the cell. Other cellular processes Internal cellular structures Techniques used to study cells Notable cell biologists