Medicine is transforming rapidly. During this era of human history, scientists are forever changing lives, because for the first time humans are not powerless against their genes! We now have the power to not only predict, but also alter our very future. The Genetic Revolution is here!
With the power of gene therapy, scientists now have a new tool that enables them to change a patient's DNA. Medical treatments usually counteract the symptoms of a disease. But with gene therapy, doctors can cure diseases. Click to learn more
The concepts described in this website might be a review for some people, or it might be a new learning experience. Click in order to learn or review the basics of biology and genetics.
Medicine is transforming rapidly. During this era of human history, scientists are forever changing lives, because for the first time humans are not powerless against their genes! We now have the power to not only predict, but also alter our very future. The Genetic Revolution is here!
DNA and Chromosomes
The human genome controls everything about life. It contains the sum total of all the genetic and biological information needed for an organism to live. It tells the organism's cells how to build and sustain itself, making it very important. This information is encoded in DNA (deoxyribonucleic acid). Nearly all the cells in a human have the same DNA. Specific sections of DNA are divided into units called genes. These genes are responsible for coding proteins. Although a cell might contains thousands of genes, the genes are not always turned on. Some genes are only turned on in the early development of the human fetus, while others are only turned on when the body specifically needs it (like when there is too much glucose in the bloodstream). By manipulating DNA and genes through gene therapy, scientists can help sufferers and alleviate their genetic diseases.
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Only about 1 percent of all our genome is made up of genes. The part of our genes that code for proteins are called exons. Between each exons are breaks called introns. When DNA is replicated and transcribed into mRNA, all of the introns are taken out, while all of the exons are joined together. It is unknown what the purpose of introns are, but some scientists suggest that they are involved in recombination, the process which results in genes with newer and different combinations of nucleotides. Thus, introns could be involved in evolution.
At the beginning and end of each genes are regulatory sequences. They are involve in important functions like starting replication and telling where the beginning and end of each genes are.
The two strands of DNA form a "double helix" ladder. The two twisted vertical support of the "ladder" is made up of a sugar called deoxyribose, and a phosphate group. The sugar and phosphate alternates each "step" down. The "rungs" of the DNA ladder are attached to each sugar. There are four types of nitrogen bases: adenine(A), cytosine(C), guanine (G), or thymine(T).
Adenine always pairs up with Thymine, and Cytosine always pairs up with Guanine.
In humans, DNA is tightly packed in the nucleus of a cell. The tightly packed DNA are called chromosomes.
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All humans have 23 pairs of chromosomes, for a sum total of 46 chromosomes. A chromosome have two arms: a "p" arm and a "q" arm. The "p" arm is the smaller arm, while the "q" arm is the bigger arm. Separating these two are centromeres, which help keep chromosomes aligned during cell division. The 23 pairs of chromosomes determine the gender of a person. A male have an X and a Y chromosome, while a female have two X chromosomes.
Telomeres are stretches of DNA located at the ends of chromosomes. They ensure that the chromosomes do not unravel. Every time a cell divides, its telomeres lose a bit of their DNA. If the telomeres get too short, then the cells will be unable to divide properly. Telomeres can be use to accurately tell the "biological" age of a person or animal.
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Videos
The following videos will review and explain the concepts described on this page.