Final answer:
Neurofibrillary tangles and β-amyloid plaque associated with Alzheimer's disease affect metabolic processes and the health of neurons in the brain, leading to the loss of synapses and ultimately the death of neurons.
Step-by-step explanation:
The neurofibrillary tangles and β-amyloid plaque associated with Alzheimer's disease affect metabolic processes and the health of neurons in the brain. These abnormal changes in the brain include the development of amyloid plaques between brain cells and neurofibrillary tangles inside neurons, which lead to the loss of synapses between neurons and ultimately the death of neurons. The presence of these tangles and plaques interferes with proper brain functioning and contributes to the symptoms of Alzheimer's disease.