Lipids study guide

What does cholesterol do in the body, what is it used for?

Cholesterol is essential for maintaining cell membrane integrity, synthesizing steroid hormones, bile acids, and vitamin D, and aiding in nerve transmission by forming myelin.

Cholesterol is made from

acetyl coA

how much of the cholesterol is esterified in the body

70%

ACAT is cholesterol acyltransferase where

intracellular

LCAT is cholesterol acyltransferase where

in circulation

fatty acids are made of what

a chain hydrocarbons with a terminal carboxyl group at one end and a methyl group at the other

fatty acids determine what in a compound

if the compound will be solid or liquid

What are the three essential fatty acids

• linoleic

• linolenic

• arachidonic

what do fecal fatty acids help detect

malabsorbtion or pancreatic disorder

why do we produce ketones

Ketones are produced from fatty acids in the liver and serve as an alternative energy source for the brain and body when glucose levels are low. causes acidification of blood tho

What are three ketone bodies

• acetone

• acetoacetate

• BHOB

what transports triglycerides

by chylomicrons

what are phospholipids made of

diglyceride esterified with phosphoric acid bound to an alcohol

Amphipathic

containing hydrophilic head groups and hydrophobic fatty acid side chains

Phospholipids act as

detergents and surfactants

Whata are the two fatty acids used for fetal lung maturity testing

• phosphatidylcholine

• phosphatidylglycerol

cardiolipin

a component of the inner mitochondrial membrane that generates electrochemical potential for substrate transport and ATP synthesis

Shingomyelin

the only phospholipid that doesnt contain a glycerol back bone from a sphingosine

What ratio is used for maturity of an inutero baby

Lecithin: shpingomyelin (more lecithin the more mature)

Prostaglandins

A group of lipids that have a hormone like action, they modulate inflammatory responses

Terpenes

Polymers of different isoprene units

What vitamin is a terpene

Vitamin A

What are the lipid soluble vitamins

ADEK

how is lipids digested and absorbed

• lipase in the stomach starts breaking down lipids

• bile is produced in the liver and aids in the digestion and absorbtion

• the pancreatic lipase breaks down fatty acids

• micelle is formed and is diffused into the mucosal cells

• lipids are transported by chylomicrons

• fat is absorbed by the small intestine

What is the order of density for lipoproteins

(most dense) HDL

LDL

IDL

VLDL

Chylomicrons (least dense)

What percentages make up chilomicrons

• 90% triglyceride

• 5% cholesterol

• 4%phospholipids

• 1% protein

What percentages make up VLDL

• 65% triglyceride

• 20% cholesterol

• 10% phospholipids

• 5%proteins

What percentages make up IDL

30% triglyceride

35% cholesterol

20% phospholipid

15% protein

What percentages make up LDL

10% triglycerides

50% cholesterol

20% phospholipids

15% protein

What percentages make up HDL

5% triglycerides

15% cholesterol

25% phospholipids

55% protein

chylomicrons are major carriers of _____ triglycerides

exogenous

VLDL carries ____ triglycerides synthesis in the liver

endogenous

VLDL creates ____ in spun spcimens

turbidity

What is IDL made from

is formed from the metabolism of Very-Low-Density Lipoprotein (VLDL) as VLDL is broken down by lipoprotein lipase and loses triglycerides.

APoE ‘s role with IDL

• ApoE requir eleed for liver uptake and continues degredation of IDL to LDL

• APOE deficiency will result in elevation of chylomicron remnants and IDL

What does LDL transport?

transports cholesterol and triglycerides from the liver to peripheral tissues. It is often referred to as 'bad cholesterol' due to its association with plaque buildup in arteries.

LDL is a major risk facto for

CHD

HDL increased levels means

decreased risk of accelerated atgherosclerosis

Apolipid proteins function as

• enzyme cofactors

• structural integrity agents

• receptor ligands

Apolipoprotein A1

the major constituent of HDL

What does ApoA1 activate and what does this cause

LCAT, removing free cholesterol from extrahepatic tissues

Apolipidprotein B 48

associated with clearing of chylomicrons, binding VLDL to LDL

Apolipidprotein B 100 is a

recognition site for LDL to bind to cell membranes

Apolipidprotein C

slows clearance of trig rich lipoproteins

Apolipid C1 inhibits and activates what

• inhibits- lipoprotein binding to LDL and VLDL receptors

• Activates- lipoprotein lipase for breakdown of triglycerides in the cell

Apo C-II activates

lipoprotein lipase

APO C-III is an inhibitor of

LPL activity

Apolipidprotein E functions to

regulate lipid levels in plasma by promoting binding of lipoproteins to the LDL receptor and a specific chylomicron remnant receptor

LpA functions to

homolog of plasminogen and may compete for binding site thereby slowing the rate of clot lysis

LPA is a contributor to

CVD, atherosclerosis and heart attacks

What are the risks of increasing atherosclerosis

• smoking

• diabetes

• obesity

• hypertension

What test detects small amounts of inflammation

HsCRP

Homocysteine

an amino acid that can accumulate and promote endothelial injury

elevated levels of homocysteine are associated with

1. cardiovascular disease

2. stroke

3. alzheimers

4. osteroporosis

5. nutritional deficiency of B6, B12, and folic acid

What is the ideal time to fast before a test

12 hrs

If someone is not fasting for the lipid testing then

the serum will become turbid w/ a layer of CM and have an increase of triglycerides

desirable level of HDL

>60mg/dl

desirable level of LDL

<100mg/dl

desirable levels of triglycerides

<150mg/dl

desirable total cholesterol

<200mg/dL

What is the method used now for cholesterol testing

enzymic cholesterol oxidase testing

triglycerides testing method has lipase liberating

glycerol

lipid testing methods interferance:Glycerol contamination from stoppers of evacuation tubes or ingestion of glycerol-coated medication can falsely _______ results

increase

Hisotric method of HDL measurements would have removed

CM, VLDL, LDL by pcpt and analyze supernatant for HDL

Most known assays for HDL dont need

pre-treatment

Friedewald equation

LDL=[total chol.-HDL] -[trigly/5]

What is the limiting factor of friewald equation

its an estimate and the higher the triglyceride the more likely LDL will be udnerestimated

in the friedewald equation the total cholesterol and HDL must be

measured by the same chemical procedure

Primary hyperlipedemia is due to…

genetic

Secondary hyperlipedemia

secondary condiion

Frederickson classification of lipid disorders

What does defective ApoB100 result in

results in increased LDL

hypoalphalipoproteinemia has low ____ and ____ deficiency associated

HDL-C and LCAT

Tangier disease characteristics

• absent HDL which means low Apo AI and Apo AII

clinical signs of Tangier disease

• hyperplastic orange tonsils

• splenomegaly

• peripheral neuropathy

Gauchers disease

deficency in Beta glucocerebrosidase, leading to acculmination of glucocerebroside in bone marrow, liver, and spleen

What are clinical signs of gauchers

• normocytic, hypochromic anemia

• thrombocytopenia

• leukopenia

• bone pain

• hepatosplenomegaly

• skin pigmentation

• gaucher cells

Niemann pick disease is caused by a deficiency in what

sphingomyelinase

clinical signs of niemannpick disease

• loss of appetite

• loss of early motor skills

• enlarged spleen and liver

• jaundice at birth

• irregular speech

For Niemann pick what would you see on a blood smear

macrophages loaded with sphingomyelin

Taysachs disease is from what ancestry

• ashkenazi jews

tay sachs is due to a deficiency in

hexosamidase A

What are the clinical signs of taysachs

psychomotor deterioration and dementia

blindness with a cherry spot in the retina

Type 1 familial hyperchylomicronemia

elevated chylomicrons

Type IIA familial hypercholesterolemia

increased LDL-C

Type III dysbetalipoproteinemia

increased VLDL with increased chylomicrons

• creamy layer w/ turbid infranate

Type IV hypertriglyceridemia

Overproduction of VLDL

• turbid

Type V hyperlipoprotenemia

mixed hyperlipidemia

-creamy and turbid

Which type of hyperlipidemia would be present if there was a deficiency in lipoprotein lipase or apoCII?

Dysbetalipoproteinemia