Chapter 4 Flashcards
Where do most synapses occur on the neuron
The spines
What type of neuron has a large number of dendritic spines
Pyramidal neurons
True or False:
All synapses occur on the dendritic spine head and none occur on the dendritic spine neck
False
What are the 3 shapes of dendritic spines
- Thin
- Mushroom
- Stubby
Where are stubby dendritic spines common
Immature brains
What does the volume of spines correlate with
Strength of connection
What is the postsynaptic density
Thick gray area where the synapse occurs
What is the nuclear envelope
Specialized portion of the RER
Are the nuclear pores hydrophillic or hydrophobic regions
Hydrophillic regions
What do the nuclear pores allow for exchange of (2)
Proteins and mRNA
What are the organelles located in the cytoplasm (cytosol) (6)
- Mitochondria
- SER
- Cytoskeleton
- Free ribosomes
- RER
- Golgi complex
Where are organelles located in the neuron
Cell body and dendrites
Are organelles located in the axon
No
What do the mitochondria do
Generate ATP for cellular energy
What are the functions of the SER (2)
- Regulates Ca2+
2. Lipid metabolism
What is the function of the cytoskeleton
Determine neuron shape
What are the 3 main structures made by cytoskeletons
- Microtubules
- Neurofilaments
- Actin microfilaments
How far do the microtubules run in the neuron
All the way down the axon
What is the function of microtubules
Develop and maintain neuron’s processes
How are microtubules formed
alpha and beta subunits arranged linearly
What are neurofilaments
Fibers that twist around each other
What are the functions of neurofilaments (2)
- Stable bones of the cytoskeleton
2. Act as cross bridges for microtubules
What is the most important microfilament
Actin
What are the 4 characteristics of actin
- Small diameter
- Concentrated at cell’s periphery
- Form a matrix
- Dynamic
What are microfilaments important for
Plasticity of the neuron
What does mercury do to microtubules
Break them down
How does mercury breakdown microtubules
It bids to newly synthesized tubulin in molecules which prevent tubulin molecules from connecting together
Where is DNA transcribed into mRNA
The nucleus
Where does the mRNA go after transcription
Leaves the nucleus through the nuclear pores and becomes associated with ribosomes
What occurs once the mRNA is associated with a ribosome
Translation
What type of proteins does the RER usually make
Membrane bound proteins like ion channels and transporters
Where do proteins from the RER go for further processing
The golgi complex
