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DNA Structure
DNA structure videos are found here. Litlle information about the structure of DNA. The backbone of the DNA strand is made from alternating phosphate and sugar residues.[8] The sugar in DNA is 2-deoxyribose, which is a pentose (five-carbon) sugar. The sugars are joined together by phosphate groups that form phosphodiester bonds between the third and fifth carbon atoms of adjacent sugar rings. These asymmetric bonds mean a strand of DNA has a direction. In a double helix the direction of the nucleotides in one strand is opposite to their direction in the other strand. This arrangement of DNA strands is called antiparallel. The asymmetric ends of DNA strands are referred to as the 5′ (five prime) and 3′ (three prime) ends, with the 5\' end being that with a terminal phosphate group and the 3\' end that with a terminal hydroxyl group. One of the major differences between DNA and RNA is the sugar, with 2-deoxyribose being replaced by the alternative pentose sugar ribose in RNA. The DNA double helix is stabilized by hydrogen bonds between the bases attached to the two strands. The four bases found in DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T). These four bases are attached to the sugar/phosphate to form the complete nucleotide, as shown for adenosine monophosphate.
Tags: structure Status: public
Created: March 14, 2009, 11:22 pm

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Adult Stem Cells and Regeneration
Doug Melton and Nadia Rosenthal are leaders in stem cell research, working primarily with mouse and human tissue. They will discuss where embryonic and adult stem cells come from and the biology of how they supply the cells the body needs. Stem cells are fundamental to biology. In the course of embryonic development, stem cells generate all the specialized cells that populate body tissues like muscle, the nervous system, and blood. In adults, reserves of stem cells repair and regenerate tissues damaged by disease and wounding. Because of the potential of stem cells to generate fresh, healthy cells, there is a huge interest in cultivating them to treat various diseases. This year\'s Holiday Lectures will explore exciting progress toward the goal of harnessing stem cells to treat diabetes, nerve damage, and heart disease.
Tags: stem cell Regeneration Status: protected
Created: March 16, 2009, 1:19 am

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Microbial Evolution
Recent genetic techniques have led to new theories of evolution and the relationships between organisms. Students examine this \\\"evolution revolution,\\\" using molecular sequences to trace the phylogenetic relationships of microbial life. Both the big picture of microbial evolution and the methods necessary for determining molecular phylogenies are examined. The metabolic pathways that produce energy create important environmental transformations. Although living organisms have diverse ways of meeting their energy needs, there is an amazing similarity between all life forms as they carry out metabolism directed to the construction and use of necessary biological molecules.
Tags: Microbial Evolution Status: private_owner_approval
Created: March 16, 2009, 1:28 am

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Protein Synthesis
This video set explains protein sythesis in detail.Protein synthesis is the creation of proteins using DNA and RNA. Proteins can often be synthesized directly from genes by translating mRNA. When a protein is harmful and needs to be available on short notice or in large quantities, a protein precursor is produced. A proprotein is an inactive protein containing one or more inhibitory peptides that can be activated when the inhibitory sequence is removed by proteolysis during posttranslational modification. A preprotein is a form that contains a signal sequence (an N-terminal signal peptide) that specifies its insertion into or through membranes; i.e., targets them for secretion.[1] The signal peptide is cleaved off in the endoplasmic reticulum.[1]. Preproproteins have both sequences (inhibitory and signal) still present. Text Reff: Wiki
Tags: Protein Synthesis Status: private_owner_approval
Created: March 16, 2009, 11:02 am

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Deconstructing Obesity Lectures
In the 2004 Holiday Lectures on Science, HHMI investigators Ronald M. Evans and Jeffrey M. Friedman discuss how the body regulates weight by carefully controlling the storage and burning of fat—and how a better understanding of these complex metabolic systems could lead researchers to treatments that curb obesity and improve public health.
Tags: obesity Status: private_owner_approval
Created: March 16, 2009, 3:49 pm

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Angiogenesis
Angiogenesis related videos. Wikipedia Text info: Angiogenesis is a physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over this, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for new blood vessel formation by splitting off existing ones. Angiogenesis is a normal process in growth and development, as well as in wound healing. However, this is also a fundamental step in the transition of tumors from a dormant state to a malignant state.
Tags: Angiogenesis Status: public
Created: March 16, 2009, 4:50 pm

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Viruses
Several Videos explaining virus cycle, structure and the way they infect. You are welcome to add videos related to this topic. Wikipedia info: A virus (from the Latin virus meaning toxin or poison) is a sub-microscopic infectious agent that is unable to grow or reproduce outside a host cell. Viruses infect all cellular life. The first known virus, tobacco mosaic virus, was discovered by Martinus Beijerinck in 1899,[1] and now more than 5,000 types of virus have been described.[2] The study of viruses is known as virology, and is a branch of microbiology.
Tags: virus Status: public
Created: March 14, 2009, 10:56 pm

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