Marvin is suffering from the early stages of alzheimer's disease. which component of his working memory is most likely to be affected? a. all of these are equally affected b. the phonological loop c. the central executive d. the visuospatial sketch pad

Correct
"All of these are equally affected."

When in Alzheimer's disease, all of the working memory is in peril. In early stages of Alzheimer's disease, all of these functions start to have problems. Phonological loop is basically the capacity to memorise speech or information in it. Central executive is the ability to switch attention from one activity to another that is needing more attention. The visuospatial sketch pad is the ability to handle visual and spatial information being able to judge distances for example. All of these are part o the working memory and are affected from the early stages of Alzheimer's disease.

Nuclear Localization Signal (NLS).

1. Importin

2. Nucleoporin

3. RanGTP

Explanation: The specific amino acid sequence motif that allows the selective transport of proteins having a molecular mass more than approximately 40 KDa into the nucleus is called Nuclear Localization Signal (NLS).

These proteins enter the nucleus through the Nuclear Pore Complex (NPC). The transit of the protein from the cytoplasm to the nucleus requires binding to a receptor called Karyopherin or Importin β, this receptor binds to the protein by direct recognition of the NLS sequence or through an adapter protein, Importin α (depending on the NLS sequence).

The passage of the complex through the NPC needs, in turn, the binding of the Importin to the Nucleoporins, proteins that form the nuclear pore.

Once the complex passes through the pore, the receptor-bound protein is released by the interaction of Importin with RanGTP, an enzyme with guanosine triphosphate (GTP) hydrolytic activity.