Dna Extraction

DNA EXTRACTION

In extracting chromatin from the cells of wheat germ there are seven steps to

follow. The optimal cell to use would be the polyploidal eukaryotic. Eukaryotes

have nucleus membrane-bound organelles, while prokaryotic does not. The

polyploidal eukaryotic cell has DNA that is held in the nucleus while the

prokaryote has DNA that floats freely around the cell. The DNA of eukaryotes is

more complex and extensive than the other. Prokaryote is a bacterial cell that

usually has DNA in one large strand and only has one chromosome while the

eukaryotic cell has more than one chromosome and is considered to be a higher

organism. Prokaryotes have an outer wall that prevents them from bursting or

collapsing due to osmotic changes. With that said, during the buffering stage the

cell could not be broken and the DNA could not be extracted.

When you add the surfactant it softens the cell and the soap dissolves and

breaks down the lipids and proteins in the phospholipid bilayer. Much like dish

detergent does to greasy dishes. Lipids are insoluble in water, the detergent

reacts with the cell and causes the molecular contents to fall out much like

hydrolysis. Without this you could never complete the extraction.

Then you add the baking soda (buffer) to the test tube. Buffer is defined as a

substance that tends to resist pH changes of a solution, thus stabilizing its

relative acidity and basicity. The baking soda will extract the DNA, nuclear

membrane and envelope out of a cell and keep it unchanged in the solution. The

baking soda must keep the pH levels at a neutral place similar to the way pool

chemicals work together. If we didn't buffer the solution we would end up with

trash. Next you add the meat tenderizer. I did further research and found

that the "hydrolyzing protein (enzyme) known as papain can either be used as

trace metal carrier or a sequestering agent that reacts with ions to form soluble

complexes."2 Both temperature and pH can bring about a change in polypeptide

shape. When a protein loses it normal configuration it is called denatured. The

tenderizer must eliminate the proteins, the membrane and envelope allowing