Monday, April 3, 2017

Foundational Concepts of DNA (2)

Corporate headquarters for your DNA is the nucleus.  At the same time, multiple branch offices reside scattered around that part of the cell out side of the nucleus called the "cytoplasm".  These branch offices are called "mitochondria" and contain a much smaller, circular shaped DNA passed down from the moms of the world.  You have come to call this mtDNA [ for this unique form of circular DNA located in the branch offices].   A big picture of this single cell organization is shown.

The yellow area is the nucleus.  The clear moist looking area is the cytoplasm.  Within each branch office [mitochondria] are specialized copy machines called "ribosomes".  Communication between the home office and all the branches use special messengers to carryout the purpose of this organization called RNA [ribonucleic acid].  Three RNA forms exist called messenger RNA... transfer RNA... and ribosomal RNA.  Universally accepted as the central tenant, the purpose of DNA is to make proteins:  1) new DNA is copied from the existing DNA, 2) messenger RNA is copied from DNA, and 3) proteins are made from this messenger RNA.  Wow...what a deal.

Monday, March 13, 2017

Foundational Concepts of DNA

The DNA revolution has produced a number of new opportunities for the eager genealogist.  Along with these opportunities come a host of unusual terms, fancy words, and confusing outcomes that can make for some, a very difficult experience.  For those, who like me, continually express...say what!...this post will begin perhaps a series of posts on some basic ideas surrounding all this DNA stuff.   So, let's begin.

Our human existence is dependent on the cell, the basic unit of life.  All  "us humans" are made up of these cells, and come from cells.  As we know it, one of the most important aspect of these cells is reproduction.  [Good thing or we would'nt be here!]  At any rate, it is during this reproduction that our genetic traits get pass down.  Now this DNA ( doxyribonucleic acid ) is the molecule of inheritance for all.  These poor cell's DNA is the thing that gets knocked around in all these labs...scraped, dipped, broken apart, multiplied, electrified, analyzed, and...the results printed out, as the "Holy Grail" of our long lost relatives still among the family tree.

The basis for most traits past down is the functional unit of inheritance call the "gene".  Each gene is given a specific position (location or loci) along the DNA molecule to be preserved and transmitted on down the family tree.  These genes control our biological processes through the production of proteins and a special modification called RNA ( ribonucleic acid ).  The genetic composition of all genes is called the "genotype".  The observable inherited traits [ physical, behavioral, physiological, etc.] is given the word "phenotype".

Foundational concepts 1) Genes form the basis of our inheritance.