When alzheimer disease appears in middle age rather than old age; it progresses more rapidly. Alzheimer's disease that results from the brain cell death. It is a neurodegenerative disease; such that there is progressive brain cell death that happens over a period of time. The brain tissue gets fewer and fewer nerve cells and connections.
A (adenine), C (cytosine), G (guanine), and T (thymine) constitute the backbone of the molecule.
<span>The DNA molecule is made up of two polynucleotide strands </span>
