Understanding Alzheimer’s Disease Enrichment LESSON 3

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Date
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Chapter 2 Lesson 3
Enrichment
LESSON 3
Understanding Alzheimer’s Disease
Imagine slowly losing your most
precious memories. You can barely
remember how to do the simplest task, let
alone recognize the face of a loved one.
This devastating scenario is common for
the nearly 5 million Americans afflicted
with Alzheimer’s disease. This progressive
brain disease attacks nerve cells in the
brain, usually in older people. It affects a
person’s memory, thinking patterns, and
behavior. In the United States, Alzheimer’s
is the sixth leading cause of death.
Currently, there is no cure.
have several functions, one of which is to
help transport materials inside cells.
Scientists are studying several proteins in
nerve cells, including the amyloid
precursor protein (APP). The exact role of
APP is unclear, but it appears to be crucial
in transporting materials and information
from the nerve cell to the axons. In
patients with Alzheimer’s disease, this cell
transport system breaks down. As a result,
the cell sends out signals that eventually
lead to its death.
Working Toward a Cure
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Cell Transport and Alzheimer’s Disease
Scientists have made great strides in
understanding Alzheimer’s disease. They
now know that certain genes have a role
in the disease. Recently, they also
discovered that Alzheimer’s might be
linked to problems associated with cell
transport. Nerve cells have axons that can
extend several feet from the main body of
the cell, which makes transport an
important issue.
As you have learned, proteins are one
type of macromolecule in cells. Proteins
Scientists are working to understand how
this transport breakdown occurs. They have
discovered an enzyme that splits APP into
two parts, one of which is called beta
amyloid. When this split occurs in a certain
way, beta amyloid forms the plaques, or
deposits of protein, found in and around the
nerve cells of Alzheimer’s patients. By
regulating the production of beta amyloid,
scientists hope to prevent the formation of
plaques and halt the death of nerve cells in
the brain. The challenge, however, lies in
keeping all the other functions of APP intact.
Applying Critical-Thinking Skills
Directions: Answer each question or respond to each statement.
1. Infer what it means when a disease is called progressive.
2. Identify the challenges that scientists face in their search for a cure for
Alzheimer’s disease.
3. Evaluate the information in the article. What does it imply about the importance
of cell transport?
Cell Structure and Function
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