Neurodegenerative diseases Flashcards
Some neurodegenerative diseases are associated with the degeneration of a particular __ ____, while others cause more widespread degeneration.
Cell type
Neuronal degeneration is driven by cellular _____,
Apoptosis
Apoptosis is triggered when _____
Clumps of misfolded proteins disrupt normal cellular function.
At high enough _______, all proteins have a risk of clumping together.
Concentrations
Evolution has favored proteins that are _____ to clumping.
Resistant
What are the 2 steps to correct proteins ?
- Protein that is resistant to clumping.
- Protein that folds into a correct 3D shape.
True or false : Cells have numerous ways of destroying misfolded protein
True
Cells have a hard time getting rid of ____ of ____ proteins
Aggregates of misfolded proteins
Reason misfolded proteins are difficult to break apart by enzymes
They are dense and hard to access for enzymes
Transmissible spongiform encephalopathy
Contagious disease that causes widespread neurodegeneration , making the brain look like a sponge.
2 names for Transmissible spongiform encephalopathy
Mad cow and Creutzfeldt-Jacob disease
Accumulation of this type of misfolded protein is responsible for transmissible spongiform encephalopathies.
Prion
Prion
Misfolded proteins that can cause other copies of the same protein to misfold, which spreads the problem throughout the brain.
Number of prion proteins needed to start a chain reaction
1
_rion protein diseases spread from cell to cell and animal to animal by means of contact with a ____
Misfolded prion protein
Death from prion protein disease usually occurs within ____
a year
Only infectious agent that is a protein (does not contain DNA or RNA)
Prion protein
Huntington’s disease
Neurodegenerative disease with a very clear genetic basis. It affects 1 in 10,000 people and runs in families.
Cause of Huntington’s
A mutation in the Huntingtin gene, which results in misfolding (long version that starts clumping to other proteins) of the huntingtin protein.
Is the Huntingtin gene mutation dominant or recessive ?
Dominant (one bad copy of the gene).
Part of the brain in which Huntingtin protein is highly expressed
Basal ganglia.
Aggragation of this protein cause parts of the basal ganglia to degenerate
Huntingtin protein
When do symptoms of Huntington’s start and cause death ?
Symptoms usually begin between 30 and 50 years of age. Death follows 15-20 years later
4 steps of Huntington’s symptoms progression
- Increasingly severe lack of coordination
- uncontrollable jerky limb movements
- dementia
- death.
True or false : movements in Huntington’s disease may seem voluntary but they are unconscious
True
The input nucleus of the basal ganglia that regulates movement receives input from ____ neurons.
Dopamine
We each have _ copies of each gene.
2
The Huntington gene has a section with more than 39 CAG repeats so the protein is a long version with more than 39 ____ acids in a row.
Glutamine
An enzyme tries to cut the amino acid up, but it leaves a ____ (the section with too many glutamine repeats) that is very prone to clumping. It will disrupt cell function.
Fragment
Death depends on the ___ of glutamine repeats.
Number (more than 39 means you will die from the disease).
A long repeat of the same nucleic acid over and over can be increased because of this.
When a cell is dividing, DNA copying machine can fall off and jump back at the wrong place
A possible treatment for protein malformation could be to get the ____ system better at fighting misfolded proteins clumps
Immune
Where is antisense DNA (RNA) inserted into in antisense therapy ?
The spinal cord
Antisense DNA complements ____
mRNA
When antisense DNA an mRNA bind together, the mRNA does not get translated into a ____.
Protein
Antisense therapy would allow the ____ protein not to get made in Huntington disease
Long
Antisense therapy alters ____ expression
Gene
Parkinson’s disease
Degenerative “movement” disorder, without an obvious genetic basis (in most instances)
