Complex Lipids And Disorders Flashcards
Name 1 storage/simple lipid
Name 2 membrane/complex lipids
Triacylglycerols
Phospholipids and glycolipids
Two sub sections of phospholipids
What is their difference
Glycerophospholipids and sphingolipids
One has glycerol backbone and other has sphingosine backbone
Sub section of glycolipids
Sphingolipids
What is difference between phospholipid sphingolipid and glycolipid sphingolipid?
Glycolipid one has a sugar attached; other one has PO4 and secondary alcohol (choline) attached
- Main role of phospholipids
2. Phospholipids serve as a component of what 3 things
- Important in cell membrane for signaling and anchoring proteins etc.
- Lipoprotein particles, pulmonary surfactants and bile
What is the most important precursor for glycerophospholipids?
Phosphatidic acid (PA)
What makes phospholipids different from each other?
All have PA, difference is in their secondary alcohol group
*What is necessary in order to synthesize phospholipids
What is its function
CDP
Activates either the alcohol or DAG component - activates the head group (similar to how UDP was activator of glucose)
Site of phospholipid synthesis?
Smooth ER
- What is lecithin
- What is it important for
- What will happen without it
- A phospholipid
- Making lung surfactant in infants
- Atelectasis (lung collapse)
How do you know when a baby lung is mature?
When lecithin/sphingomyelin ratio is greater than 2
What do phospholipases do?
Name 2 phospholipases
Degrade glycerophospholipids
Phospholipase A2 and phospholipase C
Phospholipase A2
- Releases?
- What part of body has a lot of this enzyme
- What inhibits this enzyme?
- Arachidonic acid
- Pancreatic secretions
- Glucocorticoids
Phospholipase C
- Found where in the body?
- Activated by?
- Liver lysosomes
2. PIP2 (secondary messenger signaling pathway)
What is sphingomyelin
__ + __ = sphingomyelin
Phospholipid
Ceramide + phosphocholine group
- What is ceramide
- Where is it synthesized
- What is ceramide made from
- So precursor for ceramide is
- Precursor for glycosphingolipids
- Cytosolic leaflet of ER
- Palmitoyl-CoA + serine = sphinganine; fatty acyl CoA converts sphinganine to ceramide
- Sphingosine and fatty acid
Function of sphingomyelinase
What is it necessary for
Where is this enzyme located
Hydrolyzes sphingomyelin (brings it back to ceramide+phosphocholine)
Important for myelin sheath
Lysosome
Niemann-Pick disease
1. Caused from deficiency in
- Type A vs. Type B
- Disease can be detected on slide by
- Acid sphingomyelinase
- Type A= more rare and more severe; death by age 2-3, enlarged liver and spleen due to lipid deposit
Type B= less severe; can be treated with bone marrow/enzyme replacements
~both can also give mental retardation~ - Zebra inclusion bodies
Another name for glycolipids
Essential component of
Predominantly present on
Glycosphingolipids
All membranes (like phospholipids)
Nerve cells
Glycolipids are antigenic what does that mean
Most important antigens for our purposes
Glycolipids also require?
Can have an antigen response, can cause inflammation
Blood types (A, B, AB, O) - determined by glycolipids
Ceramide
What is the substrate for synthesis of glycolipids
Nucelotide sugar - usually UDP, could also be NANA (CMP-sialic acid)
What is the difference between sphingophospholipid and sphingoglycolipid
Both have ceramide has hydrophobic tail but polar head will be different
Glycolipids are degraded where ?
How?
Lysosome
Via endocytosis (acid glycosidases)
What are the 4 classes of glycolipids
What makes them different
Glycolipids are important for
Cerebrosides, globosides, sulfatides, and gangliosides
What sugar is attached to the ceramide
Nerves/neurons/nervous system
How to make each of the glycolipids:
- Cerebrosides
- Globosides
- Sulfatides
- Gangliosides
- Ceramide +glucose (UDP)
- Ceramide + 2 or more UDP
- Ceramide + galactose
- Ceramide + Globoside + CMP-NANA
Cerebrosides are commin in
Myelin sheath, neurons, and maintaining integrity of skin
Sulfatides are common in
What is unique about these
Nerve and kidney
These are the acidic glycolipids
NANA is composed of
NANA is synthesized from
Reactivated by condensation with CTP to form
9 carbon sugar
Hexose sugar and PEP
CMP-sialic acid
Other function of globoside/ganglioside
Shock absorbers of the skull
Difference in blood type antigens
- O
- A
- B
- No galactose
- Galactose amine
- Galactose
~so difference depends on sugar that is attached to ceramide
Sphingolipidoses function
Deficiency leads to
Breakdown of sphingolipids in lysosome
Progressive mental retardation and death in early childhood
4 diseases of sphingolipidosis
Niemann pick, gauchers, tay-sachs, and fabry
Niemann Pick
- Defect in
- Symptoms
- Leads to accumulation of
- Key symptom
- Defect in
- Sphingomyelinase
- Liver/spleen enlargement, mental retardation
- Sphingomyelin
- Cherry red spot on macula of eye
Tay-Sachs disease - common
- Defect in
- Symptoms
- Leads to accumulation of
- Common in what kind of people
- Defect in
- Beta Hexosaminidase A (Hex A)
- Mental retardation, blindness, death by age
- Ganglioside Gm2
- Ashkenazi Jews
~also cherry red spot, but no organ involvement
Gauchers disease - most common
- Defect in
- Symptoms
- Leads to accumulation of
- How will cell appear on histology slide
- Defect in
- Glucocerebrosidase
- Liver/spleen enlargement, osteoporosis, mental retardation in infantile form only
- Glucocerebroside
- Cell looks like crumpled tissue paper
Fabrys disease
- Defect in
- Symptoms
- Leads to accumulation of
- Defect in
- Alpha galactosidase
- Skin rash, kidney failure, pain in lower extremities
- Trihexosylceramide
