LIPIDS AND LIPO

Question 1

petroleum industry

Answer 1

Lipoproteins

Question 2

redistributing dietary and hepatic-synthesized
triglycerides to peripheral cells mostly during fasting for energy needs or
storage as fat.

Answer 2

The very-low-density lipoproteins (VLDLs)

Question 3

rich in cholesterol, which
start out as VLDLs, are like nearly empty tankers that just deliver cholesterol
to peripheral cells and return to the liver after their main cargo, triglycerides,
have been off loaded.

Answer 3

low-density lipoproteins (LDLs)

Question 4

are the cleanup
crew, gathering up excess cholesterol for transport back to the liver.
Cholesterol is used by the body for such useful functions as facilitating
triglyceride transport by lipoproteins and maintaining the normal structure
and integrity of cell membranes, and as a precursor for steroid hormone
synthesis, but when in excess, it can lead to cardiovascular disease.

Answer 4

high-density lipoproteins (HDLs)

Question 5

-Commonly referred to as fats.
-composed of mostly carbon-hydrogen ( C-H )
bonds, they are a rich source of energy and an
efficient way for the body to store excess calories.
-Insoluble in blood and water, but soluble in
organic solvents
-Transported by lipoproteins , namely
triglycerides, phospholipids, cholesterol, and fat
soluble vitamins (ADEK)

Answer 5

LIPIDS

Question 6

Linear chains of C-H bonds that terminate with a carboxyl group
(- COOH).

As to length can be classified as short-chain (4 to 6 carbon atoms),
medium-chain (8 to 12 carbon atoms), long-chain (12 to 18 carbon
atoms), or very-long-chain (>20 carbon atoms) fatty acids.
As to the number of C=C bonds, they can be saturated or unsaturated

Mostly found as constituents of phospholipids or triglycerides
Mainly derived from hydrolysis of triglycerides in adipose tissues
Small amount is present in plasma, most is bound to albumin.

Important source of energy

Provide the substance for conversion of glucose

Reference value: 9-15 mg/dl

Answer 6

FATTY ACIDS

Question 7

Triacyglycerol (neutral fat)

3 molecule of fatty acid and one molecule of glycerol by ester bond

Hydrophobic and water soluble

Main storage of lipid in man ( adipose tissue) - 95% of stored fat and the predominant form
of glyceryl ester found in plasma

Breakdown of TAG are metabolized, their fatty acids are release to the cells and converted
into energy

Breakdown of TAG are facilitated by:
> lipoprotein
> lipase
> epinephrine
> cortisol

Answer 7

TRIGLYCERIDES

Question 8

Fasting requirement for triglycerides

Answer 8

12-14 hours

Question 9

Reference value for lipids

Answer 9

9-15 mg/dl

Question 10

Reference value for triglycerides in Normal state

Answer 10

<150 mg/dl

Question 11

Reference value for triglycerides in Borderline High

Answer 11

150-199 mg/dl

Question 12

Reference value for triglycerides in High TAG

Answer 12

200-499 mg/dl

Question 13

Reference value for triglycerides in Very High TAG

Answer 13

200-499 mg/dl

Question 14

Chemical Methods

Answer 14

I. Colorimetric Method (Van Handel and Zilversmith)
II. Flourometric Method (Hantzsch Condensation)

Question 15

Enzymatic Methods

major interference; normally present in plasma
concentration below 0.163 mmol/L, equivalent to 14 mg/dL TAG
concentration

Answer 15

Glycerol

Question 16

Hydrolysis of TAG to free fatty acids and glycerol,
followed by the phosphorylation of glycerol to glycerophosphate

Answer 16

Glycerol Kinase Method

Question 17

Involves alkaline
hydrolysis (saponification) using alcoholic KOH, solvent extraction with chloroform
and the extract is treated with silicic acid (chromatography) to isolate TAG and a
color reaction with chromotopic acid, giving rise to a pink end color

Answer 17

CDC reference method (Modified Van Handel and Zilversmith)

Question 18

Increased Triglycerides BECAUSE OF

Answer 18

Hyperlipoproteinemia Types I,
IIb, III, IV, and V

Nephrotic syndrome

Alcoholism

Hypothyroidism

Pacreatitis

Question 19

Decrease Triglycerides BECAUSE OF

Answer 19

Malabsorption

Hyperthyroidism

Malnutrition

Brain Infarction

Question 20

Most abundant lipids derived from phosphatidic acid
* Originates in the liver and intestine
* Produced from the conjugation of two fatty acids and phosphorylated
glycerol
* Amphipathic lipid, contains polar hydrophilic head groups and non polar
hydrophobic fatty acid side chains
* Similar structure to triglycerides, except they contain two fatty acids
* Alter fluid surface tension
* Participate in cellular metabolism and blood coagulation

Answer 20

PHOSPHOLIPIDS

Question 21

Reference value of PHOSPHOLIPIDS

Answer 21

150-380 mg/dL

Question 22

what are the forms of Phospholipids

Answer 22

Lecithin/Phosphatidyl choline — 70%
* Spingomyelin — 20%
* Cephalin — 10%
- Phosphatidyl ethanolamine
- Phosphatidyl serine
- Lysolecithin + Inositol Phosphatide

Question 23

Only phospholipid in membranes that is not derived from glycerol but from an amino
alcohol called sphingosine
* Essential component of cell membrane
* Accumulates in liver and spleen of patients suffering Niemann-Pick disease
* Serve as reference material during 3rd trimester of pregnancy because its
concentration is constant as oppose to lecithin

Answer 23

SPHINGOMYELIN

Question 24

• Unsaturated steroid alcohol containing 4 rings, and it has a single C-H
  side chain tail similar to fatty acid
• Amphipathic hydroxyl group in the A-ring is the hydrophilic part of
  cholesterol
• Found on the surface of lipid layers; synthesized in the liver
• Almost exclusively synthesized by animals; not catabolized by most
  cells-does not serve as source of fuel
• Transport and excretion is promoted by estro

Answer 24

CHOLESTEROL/ 3-HYDROXYL-5,6-CHOLESTENE

Question 25

CHOLESTEROL/ 3-HYDROXYL-5,6-CHOLESTENE (FUNCTION)

Answer 25

1. Progestins 2. Glucocorticoids 3. Mineralocorticoids 4. Androgen 5. Estrogen

Question 26

WHAT ARE THE Forms of Cholesterol

Answer 26

Cholesterol Ester 70% Free cholesterol 30%

Question 27

Chemical Methods for CHOLESTEROL/ 3-HYDROXYL-5,6-CHOLESTENE

Answer 27

1. Liebermann Burchardt Reaction End product: Cholestadienyl Monosulfonic Acid (Green) 2. Salkowski Reaction End product: Cholestadienyl Disulfonic Acid (Red)

Question 28

General Methods for CHOLESTEROL/ 3-HYDROXYL-5,6-CHOLESTENE

Answer 28

1. One-step Method = colorimetry 2. Two-step Method = extraction + colorimetry 3. Three-step Method = saponification + extraction + colorimetry 4. Four-step Method = saponification + extraction + colorimetry + precipitation

Question 29

Increased Cholesterol

Answer 29

Hyperlipoproteinemia types II, III, V Biliary cirrhosis Nephrotic syndrome DM Alcoholism Primary hypothyroidism

Question 30

Decreased Cholesterol

Answer 30

Severe hepatocellular Hyperthyroidism Malnutrition Malabsorption syndrome

Question 31

General Lipoprotein Structure

Answer 31

Apolipoprotein Cholestereyl-ester Triglycerides Cholesterol Phospholipids

Question 32

Apolipoproteins are located on the surface of lipoprotein particles. They help maintain the structural integrity of lipoproteins. They serve as ligands for cell receptors. They act as activators and inhibitors of enzymes that modify lipoprotein particles. Apolipoproteins contain an amphipathic α helix structural motif. This motif allows the proteins to bind to lipids. Amphipathic helices have hydrophobic and hydrophilic regions. Keep the lipids in solution during circulation through the blood stream Aid in solubilization of the lipids and also in their transfer from the gastrointestinal tract to the liver Interact with specific receptors and direct the lipids to the correct target organs and tissues in the body

Answer 32

Apolipoprotein

Question 33

major lipoproteins

Answer 33

Chylomicrons (CM) Very Low Density Liproprotein/Pre-Beta Lipoprotein (VLDL) High Density Lipoprotein/Alpha Lipoprotein (HDL) Low Density Lipoprotein/ Beta Lipoprotein (LDL)

Question 34

Largest and less dense of lipoprotein particles * Produced in the intestine from dietary fat; completely cleared within 6-9 hours post prandial * Transport exogenous/dietary TAG to liver, muscle and fat depot * Major composition: 90% TAG + 1-2% protein * Apolipoprotein: Apo B-48, Apo A-1, Apo C and Apo E * Density: <0.95 kg/L

Answer 34

Chylomicrons (CM)

Question 35

Secreted in the liver * Transport endogenous TAG to liver, muscle, fat depot and peripheral tissues * Major composition: 65% TAG + 6-10% protein + 16% CE * Apolipoprotein: Apo B-100, Apo C and Apo E * Density: 0.95-1.006 kg/L

Answer 35

Very Low Density Liproprotein/Pre-Beta Lipoprotein (VLDL)

Question 36

* Smallest lipoprotein (5-12nm) but the most dense * Produced in the liver and intestine *Transports excess cholesterol from the tissues and return it to the liver (reverse cholesterol transport) - HDL maintains the equilibrium of cholesterol in peripheral cells by the reverse cholesterol transport pathway. * CDC reference method: ultracentrifugation, precipitation with heparin-MnCl, and AbellKendall Assay * Major composition: 30% phospholipid + 45-50% protein + 20% CE * Apolipoproteins: Apo A-I, Apo A-ll and Apo C * Reference value: 40 mg/dl * Density: 1.063-1.21 kg/L

Answer 36

High Density Lipoprotein/Alpha Lipoprotein (HDL)

Question 37

Synthesized in liver * Major end product from the catabolism of VLDL *Transport cholesterol to the peripheral tissues-it carries most of the circulating cholesterol and transports cholesterol to hepatic and extrahepatic tissues, where it is taken up by the LDL-receptor-mediated endocytosis * Most cholesterol rich of lipoproteins and most atherogenic * Major composition: 50% CE +18% protein and phospholipid * Apolipoproteins: Apo B-100 and Apo E * Research method: Beta quantification * Reference value: <100 mg/dL * Density: 1.019-1.063 kg/

Answer 37

Low Density Lipoprotein/ Beta Lipoprotein (LDL)

Question 38

* An aliquot of plasma (2 mL) is placed into a 10 x 75-mm test tube and allowed to stand in the refrigerator at 4° C undisturbed overnight. * Chylomicrons accumulate as a floating "cream" layer and can be detected visually. * A plasma sample that remains turbid after standing overnight contains excessive amounts of VLDL

Answer 38

STANDING PLASMA TEST

Question 39

MINOR lipoproteins

Answer 39

Intermediate Density Lipoprotein (IDL) Lipoprotein (a) / Lp(a)

Question 40

* Product of VLDL catabolism- "VLDL remnant" * Converted to LDL- "subclass of LDL" * Defective clearance of IDL in type 3 hyperlipoproteinemia is probably due to deficiency of Apo E-III * Major lipoprotein: Apo B-100 * Density: 1.006-1.019 kg/L

Answer 40

Intermediate Density Lipoprotein (IDL)

Question 41

Intermediate Density Lipoprotein (IDL)

Answer 41

Lipoprotein (a) / Lp(a)

Question 42

ABNORMAL LIPOPROTEINS

Answer 42

Lipoprotein X B-VLDL (floating ẞ lipoprotein)

Question 43

The four major pathways involved in lipoprotein metabolism:

Answer 43

* Lipid Absorption Pathway * Exogenous Pathway * Endogenous Pathway * Reverse Cholesterol Transport Pathway

Question 44

* Found in obstructive jaundice and LCAT deficiency * Specific and sensitive indicator of cholestasis * Lipid content is mostly phospholipid and free cholesterol * Contains Apo A and Albumin

Answer 44

Lipoprotein X

Question 45

*"abnormally migrating B-VLDL" * Found in type 3 hyperlipoproteinemia or dysbetalipoproteinemia * "VLDL rich in cholesterol" * There is an accumulation of IDL because of failure to fully convert VLDL to LDL * Density: <1.006 kg/L

Answer 45

B-VLDL (floating ẞ lipoprotein)

Question 46

DISORDERS ASSOCIATED WITH LIPIDS AND LIPOPROTEINS

Answer 46

Arteriosclerosis Hyperlipoproteinemia Hypercholesterolemia PCSK9 HYPERTRIGLYCERIDEMIA Combined Hyperlipidemia Lp(a) Elevation Non-HDL Cholesterol Hypoalphalipoproteinemia Familial Hypercholesterolemia (Type 2a) Hypobetalipoproteinemia Abetalipoproteinemia (Bassen-Kornzweig Syndrome) Niemann-Pick disease (lipid storage disease) Familial Dysbetalipoproteinemia (Type 3 Hyperlipoproteinemia) Tangier's Disease Lipoprotein Lipase (LPL) Deficiency Lecithin Cholesterol Acyl Transferase (LCAT) deficiency Tay-Sachs disease Chylomicron Retention Disease (Andersen's Disease) Sitosterolemia

Question 47

FREDRICKSON CLASSIFICATION

Answer 47

Type 1- Hyperchylomicronemia/Familial LPL Deficiency Type 2- Hyperlipoproteinemia Type 3 Dysbetalipoproteinemia Type 4 Hyperlipoproteinemia/ Hypertriglyceridemia Type 5 Hyperlipoproteinemia