Transcript Document

Definition & its
Classification
Classification of lipids (examples)
SIMPLE LIPIDS
COMPOUND LIPIDS
DERIVED LIPIDS
TAG
WAXES
PHOSPHOLIPID
SPHINGOLIPIDS
CHOLESTEROL
STEROID HORMONES
FATTY ALDEHYDES
KETONE BODIES
FAT SOLUBLE VITAMINS
(ADEK)
EICOSANOIDS
Prostaglandin
Leukotriene
BILE ACIDS/SALTS
GLYCEROL
Phosphosphingolipid
GLYCOLIPID
Cerebosides
Gangliosides
Sulfatides
LIPOPROTEINS
Functions of Lipids
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Energy provision as ATP
Building block
Thermal Insulator
Specialized functions
– Messenger/Signaling
– Bone strength
– Visual pigment
– Antioxidant
– Electron Transport Chain
Simple fat have simple function
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They are neutral lipid
Storage in adipose tissues
Body contouring
Insulation
Store of energy
Complex/Compound Lipids
• Esters of fatty acids with alcohol, containing
non-lipid Group (PO4, Nitrogenous base, or
sugar)
• Compound Lipids are Further Classified as:
1. PHOSPHO-LIPIDS
2. GLYCO-LIPIDS
3. PROTEO-LIPIDS (LIPO-PROTEINS)
4. SULPHO-LIPIDS
PHOSPHOLIPIDS
1. Glycerophospholipids (Backbone is Glycerol)
• Phosphatidic acid is the parent compound for all
• PO4 with additional group form Polar head.
• 2 Fatty acids form non polar tail.
• Amphipathic molecule
Types of Glycero-phospholipids
• depending upon the type of head alcohol Common
GPL are
1. Phosphotidyl Choline. (Lecithin)
1.
2.
3.
4.
5.
Present in membrane, plasma, & bile
Forms component of cell membrane
Decrease surface tension of aqueous later of lung
Detergent property solubilize cholesterol in bile (Gall stone)
LCAT esterify cholesterol in HDL
2. Phosphotidyl Ethanol amine.(Cephalin)
1. Brain lipid
Types of Glycero-phospholipids
3. Phosphotidyl Serine.
Apoptosis
4. Phosphotidyl Inositol
1. Precursor of Second Messengers
5. Phosphatidyl Glycerol.
6. Cardiolipin.
3.
Mitochondrial Membranes
2. Sphingolipids (backbone is Sphingosine)
• Ceramide is the parent compound for
spingolipid.
• Amino alcohol (sphingosine)
• Fatty acid
GLYCOLIPIDS
Ceramides + Sugar residue (β-glycosidic bond)
1. Cerebrosides
Glucosylcerebrosides
Ceramides + Glucose
Non neuronal accumilate in Liver (GAUCHER’S Disease)
Galactosylcerebrosides
Ceramides + Galactose
Neuronal tissues- White matter
Sulfatides
Ceramides + Galactose + Sulfate
Ceramides + Sugar residue (β-glycosidic bond)
2. Gangliosides
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Ceramides + branched oligosaccharides
Have acidic sugar (Sialic Acid/NANA)
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Glc-Gal-GalNA-Gal ………………….GM1
NANA
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Glc-Gal-GalNA-Gal ………………….GM2
NANA
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Glc-Gal- ………………….GM3
NANA
• Oligosaccharide present on outer membrane
for receptor of GP hormones
• Gangliosides present in brain & liver
• TAY SACH’s disease occur B/o deposition of
gangliosides in brain (hexoseaminidase)
BRAIN LIPIDS
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Caphalin
Sphingomyelin
Cerebresides (Galactosyl)
Gangliosides
Cholesterol
• 35% of the dry weight of brain
III-LIPOPROTEINS
• Clusters of lipids
associated with
proteins that serve as
transport vehicles for
lipids in the lymph and
blood
Lipoproteins
• Distinguished by size and
density
• Each contains different
kinds and amounts of
lipids and proteins
– The more lipid, the lower
the density
– The more protein, the
higher the density
Lipoproteins
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Chylomicrons
VLDL – Very low density lipoprotein
IDL – Intermediate density lipoprotein
LDL – Low density lipoprotein
HDL – High density lipoprotein
Properties of Plasma Lipoproteins
Property
Chylomicron
Density
(g/mL)
<1.006
VLDL
IDL
LDL
HDL
<1.006 1.006- 1.019- 1.063
1.019 1.063 -1.21
Lipids
(%)
98
92
85
79
50
Protein
(%)
2
8
15
21
50
Lipids (%) in Plasma Lipoproteins
Lipid
Chylomicron
VLDL
IDL
LDL
HDL
Cholesterol
9
22
35
47
19
Triglyceride
82
52
20
9
3
Phospholipid
7
18
20
23
28
Lipoproteins and cardiovascular
disease (CVD) risk
• LDL is positively associated with CVD
• HDL is negatively associated with CVD
Cardiovascular disease (CVD)
Cardio = heart, & Vascular = blood vessels
• General term for all diseases of the heart and
blood vessels
– Atherosclerosis is the main cause of CVD
• Atherosclerosis leads to blockage of blood
supply to the heart, damage occurs (coronary
heart disease, CHD)
LDL and atherosclerosis
Recommended blood lipids
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Total cholesterol: <200 mg/dL (WHO-<150)
LDL cholesterol: <130 mg/dL
HDL cholesterol: >35 mg/dL
Triglycerides: <200 mg/dL
Effect of lipids on lipoproteins and CVD
risk
• Dietary cholesterol
– No effect on blood cholesterol
• Saturated fats
– Raise LDL
• Trans fats
– Raise LDL and lower HDL
• Monounsaturated fats
– Lowers LDL
• Omega-3 (n-3) polyunsaturated fats
– Lowers blood cholesterol
What is Cholesterol?
• Steroids are derived
lipids in which the basic
or principle structure is
Cyclopentano Perhydro
Phenanthrne Nucleus
• (CPPP Nucleus)
(Steroid Nucleus)
• Examples:
– Steroid hormones,
Vitamin D etc.
Derived lipid (cholesterol)
• 27-C cyclic isoprene unit, derived from acetyl CoA
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Phenenthrene nucleus
Cyclopentane ring
OH gp at 3rd C
Double bond at 5th position
Aliphatic chain at C-17
Methyl gp at C18,19.
Cholesterol is white waxy compound
Widely distributed in almost all the tissues of the body
especially in brain, other nervous tissues, adrenals and liver.
Desirable Blood Cholesterol Levels
• Total cholesterol Less than 200 mg/dL
• LDL ("bad" cholesterol) Less than 100 mg/dL
• HDL ("good" cholesterol)40 mg/DL or higher
• Triglycerides Less than 150 mg/dL
Important biological
functions Of Cholesterol
• One of the important members of
membrane lipids.
• Precursor of Steroids & Vitamin D.
• Forms Adrenal hormones
• Forms Bile acids and salts
• Relation with various diseases like:
– Hypertension
– Diabetes Mellitus
– Thyroid Diseases.
Eicosanoids
• Porstanoids
– Prostaglandins (PGs)
– Prostacyclins (PGIs)
– Thromboxanes (TXs)
• Leukotrienes (LTs)
• Lipoxins (LXs)
Eicosanoids Derivatives of the
Arachidonic acid
• Physiologically they are considered to act as
local hormones.
• Many of these compounds have profound
effects on smooth muscles, inflammation,
blood clotting and many other important
biological functions.
Prostaglandins Belong to a group of
20 Carbon fatty acids containing a 5
Carbon ring in their structure
• They are of interest because of their
extraordinary physiological and
biochemical effects on:
– Smooth muscles of many organs like
blood vessels, uterus, kidney, stomach.
– Adipose tissues.
• On the basis of difference in the chemical
structure various types of prostaglandins
are described, such as Pgα, Pgβ, Pg and so
Different types of prostaglandins have variety
of effects on different tissues
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Role on adipose tissues.
Stimulation of inflammation.
Role on kidney.
On cardiovascular system.
On respiratory system.
Effects on platelet aggregation.
On gastrointestinal tract.
On female reproductive system.
On central nervous system.
Clinical Application of Prostaglandins in
Medical Practice
• To facilitate the labor or therapeutic
abortion.
• Contraception.
• Asthma.
• Management of blood pressure.
• Gastric ulcer.
• Prostaglandin inhibitors commonly used as
Analgesics (Pain killers)