Neural Lipids Flashcards
what is neural lipids?
Lipids found in the brain
Nerve cells mould (modify) the lipid fabric (composition) of their
membranes to ease?
vesicle fusion, regulate ion fluxes and create
specialized microenvironment
what are the function of membrane lipids?
controls
protein traffic, facilitates recognition between cells and leads to the
production of hundreds of lipid mediator
is lipid solublle in water?
mostly, but not all of them
what are lipids?
hydrophobic or amphipathic small molecules derived by condensation of hydrocarbon units in chains or rings
what are the 4 catergories of lipids?
- fatty aclys(FA)
- glycerophospholipids(GP)
- sphinolipids (SP)
- sterol lipids (ST)
Are fatty acids free in membranes?
never, but always attached to phospholipids and sphingolipids
Which sphingolipid lacks glycerol and is the precursor to various complex sphingolipids?
Sphingosine.
Identify the common sphingolipid that contains phosphocholine and is a major component of cell membranes
Sphingomyelin.
What characterizes globosides in terms of sugar content?
Globosides contain 2 or more sugars
what deficiency leads to Krabbe disease?
galactosylceramidase
what is hugely toxic to oligodendrocytes and other cells?
accumulation of galactosylsphigosine
What is the primary precursor of bile acids and steroid hormones in animals?
Cholesterol
Name a major function of cholesterol in biological membranes.
controls membrane fluidity and packing, providing mechanical strength and supporting membrane organization and stability
Where is the highest concentration of cholesterol found within the human body?
Approximately 25% of body cholesterol is located in the brain.
In terms of solubility, describe cholesterol in water.
Cholesterol is water-insoluble.
what are the function of lipids in neural lipids?
- insulating myelin to reduce ion leakage and speed up electrical
signals - Polarisation of neurons, vesicular trafficking at synapses
(exocytosis) - Rearranging dendritic spines to mediate synaptic plasticity
what do paranodal junction do?
limits current leaks from the node of Ranvier
How does the level of plasmalogens change with age, and at what point do they typically start to decline?
Plasmalogen levels increase with age up until 30-40 years and then decline with age.
In what neurodegenerative condition has the loss of plasmalogens been correlated with the onset of dementia?
dementia in Alzheimer’s Disease (AD).
What consequence arises in transgenic mice lacking plasmalogens, specifically concerning myelin and axons?
leads to demyelination, loss of myelin compaction, and axonal loss.
what is the membrane fluidity depends on?
temperature
How do the conical and inverted conical shapes of lipids minimize energy requirements for lipid packing in highly curved membrane structures?
by reducing curvature frustration
what is the role of lipids in exocytosis?
Only in protozoa evidence of lipids involved in
fusion of vesicles
what are the 2 membrane properties?
asymmetric and have specialised domain
