BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The amyloid fibrils are composed of the amyloid- peptide (A), a 39–43 amino acid residue peptide produced by cleavage from a larger amyloid precursor protein, APP. The A peptide is known to be present in unaffected individuals and is thought to have a normal physiological role.

Detailed explanation-2: -Amyloid proteins are a group of proteins that share the common characteristic of the ability to form beta-pleated sheets, which are resistant to proteolysis. More than 20 different types of amyloid have been identified.

Detailed explanation-3: -The beta-amyloid protein involved in Alzheimer’s comes in several different molecular forms that collect between neurons. It is formed from the breakdown of a larger protein, called amyloid precursor protein. One form, beta-amyloid 42, is thought to be especially toxic.

Detailed explanation-4: -By electron microscopy, amyloid appears as a beta-pleated sheet composed of fibrils ranging from 7.5 to 10 nanometers in width that are non-branching and of indefinite length and are associated with a P component which is donut shaped and pentagonal. The P component is very similar to serum C reactive protein.