Lipid Metabolism Flashcards
Tay Sachs disease
Lack of HEXA which breakdown gangliosides
Cherry red spot in macula (eye)
Structural lipids includes
Phospholipids and Glycolipids
Phospholipids include, and their structure
Glycerol phospholipids/Phosphoglyceride
Glycerol backbone with two FA via ester linkage and choline/ethanolamine via phosphodiester linkage
I.e. Plasmalogens = cardiomyocytes plasma membrane. Protection against radicals
Sphingolipid structure
Sphingosine backbone with FA via amide linkage
I.e. Sphingomyelin - neuron myelin sheath
Glycolipids include
Glycosphingolipids and Gangliosides
Glycosphingolipid
Sphingosine backbone with FA.
Involved in nerve impulses
Simple - cerebroside
Complex - 2+ goboside
Ganglioside
Nerve tissue
ABO blood group
Oligosaccharide head attached to Salic acid residues
Stem cell markers
Saturated fats
Unbranched, single bonds, solid at room temp
I.e. Palmitic acid
Monosaturated Fats
1 double bond
Waxy.
I.e. Palmitoleic acid.
Oliec
Polyunsaturated fats (PUFAs)
Two or more double bonds
Cis = healthy
I.e. Arachidonic acid
Linolenic
Triaglycerides include:
Glucagon (mobilize) and insulin (store) –> lipoprotein lipase releases TG for storage
Chylomicrons
Largest and least dense
Synthesized in ER of small intestine
Core lipid: dietary TG, cholesterol esters
B48, C,E
ApoC
A lipoprotein lipase enzyme converts TG to free FA and glycerol which is stored and oxidized in the target tissues
ApoE
Binds liver receptors involved in Chylomicron uptake to be degraded
B48
Acquires ApoC and ApoE from HDL while moving through blood and lymph system
VLDL
High in diet fat, cholesterol and converted into TG and packaged in muscle and adipose tissue for storage and usage
Core lipids - endogenous TG
B100, ApoC, ApoE
IDL is a remnant and converted to LDL
LDL
Synthesized via VLDL
Core lipids- endogenous cholesterol, esters
ApoB-100
Cholesterol converted to extra hepatic tissue
HDL
Synthesized in liver and nascent intestine
Core lipid - endogenous
ApoA, ApoC, ApoE = nascent HDL
Collects cholesterol via all transfer proteins towards liver to be excreted.
Equation to determine cholesterol levels = plaque
LDL = VLDL - IDL
Abetalipoproteinemia
Deficiency in ApoB48 and ApoB-100
Low LDL, VLDL, CHylomicrons = no absorption or transport
Symptoms: fatty stool, early death
Familial defective ApoB-100
Mutant in ApoB-100
LDL receptor binding problem resulting in high cholesterol LDL levels
Autosomal dominant
ApoA
Good
High HDL component
ApoB
Bad
High chylomicrons, VLDLs and LDLs
MI risk assessment using ApoB/ApoA ratio
Zellwegers syndrome
No peroxisomes
Facial features, liver, CNS
Infantile Refsum Disease
High serum copper and iron, acidic serum and CSF
Hypomyelination
ELISA function
To measure Ag-Ab quantification of hormones/enzymes/NTs that are present in blood/tissues/fluids,etc.
The target protein is the Ag, then lab made Ab binds
Direct, Indirect, and Sandwich (most sensitive)
Neimann Pick Disease
Rare autosomal recessive
Acid sphingomyelinase enzyme = accumulation of sphingomyelin in brain, spleen, liver
Mental retardation
Type A: neurological, early infancy
Type B: non-neurological, no mental retardation, preteen
HMG-CoA Reductase
Rate limiting step of cholesterol biosynthesis, forming Mevalonate from HMG-CoA.
Activated by insulin which dephosphorylates HMG via protein phosphatase
Inhibited by glucagon/Epi which activates protein kinase which phosphorylates HMG-CoA Reductase
Systemic primary carnitine def.
No carnitine transporter
Low plasma carnitine
High urine carnitine
Muscle weakness, hypoketotic hypoglycemia
CPT-1 def
Long chain FA cannot go into mito
High plasma carnitine
Early childhood
CPT-II def
Adult form- not fatal, muscle damage
Severe infantile form - sudden death risk
Fatal neonate form - highly fatal
Intermediates of the biosynthesis of cholesterol
- Isopentenyl-pyrophosphate
- Geranyl-pyrophosphate
- Farnesyl-pyrophosphate —> prenylated proteins such as: Rho/Ras, Dolichol, ubiquinone/Coenzyme Q, Heme a
SREBP - sterol regulatory element binding protein
Promotes transcription of HMG CoA reductase forming endogenous cholesterol biosynthesis
During low Intracellular cholesterol
