Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st year (First Year) Biochemistry ppt lectures Topic 2 L3 Lipid Alcohols Notes. - biochemistry notes pdf, biochemistry mbbs 1st year notes pdf, biochemistry mbbs notes pdf, biochemistry lecture notes, paramedical biochemistry notes, medical biochemistry pdf, biochemistry lecture notes 2022 ppt, biochemistry pdf.
Study Of Derived Lipids
Alcohols
Alcohols Involved In
Lipid Structures
3 Alcohols Involved In
Various Forms Of Lipids
1. Glycerol
(C3-Trihydric Alcohol)
2. Sphingol/Sphingosine
(C18-Dihydric Alcohol)
3. Cholesterol
(C27-Monohydric Alcohol)
Alcohols Of Lipids
Are
Classified
As
Derived Lipids
Glycerol is a
Derived Lipid
Obtained from Hydrolysis of
Simple and Compound Lipids
Glycerol/ Glycerin
? Glycerol [C3 ]is a POLYOL
? Glycerol is chemically Trihydric
Alcohol (3 ?OH groups)
? Glycerol has potency to interact
with 3 same or different Fatty
acids .
vGlycerol is a backbone of
Glycerol based Lipids viz:
v Triacylglycerol
v Glycerophospholipids
Glycerol Sources To Human Body
Endogenous and Exogenous Sources
Glycerol
Glucose
Source Of Glycerol To Human
body
? Glucose is responsible for biosynthesis of Glycerol
in human body
? Glucose transforms to Glyceraldehyde,
? Glyceraldehyde on reduction forms Glycerol.
? Glycerol formed is then used for Biosynthesis
of Glycerol based Lipids.
? Glycerol released from hydrolysis of Glycerol
based Lipids is transformed to Glucose.
SPHINGOSINE/SPHINGOL
? Sphingosine is a derived
Lipid.
? Obtained from Hydrolysis of
Sphingolipids
? Sphingosine is a C18, complex Dihydric,
Amino alcohol.
? Sphingosine is biosynthesized in human
body using amino acid Serine.
? Serine provides NH2 group of
Sphingosine.
? Sphingosine forms Sphingolipids
/Compound Lipids with Alcohol
Sphingol
? Examples of Sphingolipids:
?Sphingophospholipids
?Sphingoglycolipids
What Is a Ceramide?
? A Fatty acid linked to an amino
group of Sphingosine
? With an amide linkage form a
Ceramide.
? Ceramide if linked to Phosphate and
Nitrogenous groups forms
Sphingophospholipids.
? Ceramide linked to Carbohydrate
moieties form Sphingoglycolipids.
Sphingosine Based Lipids
Sterols
Common Sterol And Steroids
Vitamin D3
Cholesterol
(cholecalciferol)
(a sterol)
Testosterone
Stigmasterol
(a steroid
(a phytosterol)
hormone)
? Sterols are chemical y
complex, organic monohydric
Alcohols.
? Sterols has cyclic ring
structures
?Sterols have a parent ring
?Cyclo Pentano Perhydro
Phenantherene (CPPP)
nucleus.
Examples Of Sterols
? Cholesterol (Animal Sterol)
? 7 Dehydrocholesterol( Provitamin D)
? Coprosterol (Excretory form Cholesterol)
? Ergosterol (Plant Sterol)
? Sitosterol (Plant Sterol)
Cholesterol
Most abundant Sterol of Human body
Cholesterol
? Cholesterol is an Animal Sterol .
? Cholesterol means Solid Alcohol as it
was first obtained from gal stones of
bile.
? Cholesterol is excreted via bile hence
richly composed in bile ,Gal stones.
Cholesterol
Is A Derived Lipid
? Cholesterol is classified as
Derived Lipid.
? It is derived from hydrolysis of
Cholesterol Ester (Human Body
Wax).
Chemical Structures Of
Cholesterol and Cholesterol Ester
Pentahydrophenantrene
(Sterane)
Structure Of Cholesterol
? Cholesterol is complex, cyclic,
unsaturated, monohydric Alcohol.
? Molecular formula is C27H45OH
? Cholesterol has parent nucleus as
Cyclo Pentano Per hydro
Phenantherene ring system(CPPP).
? The structure of CPPP has four
fused cyclic rings (A,B,C and D)
? Hexane ring A,B,C is a
Phenatrene nucleus.
? D ring is Cyclopentane ring.
? The Structure of Cholesterol Possess:
1. Hydroxyl group (-OH) at C3.
2. Double bond between C5 and C6.
3. 5 Methyl (-CH3) groups.
4. 8 Carbon side chain linked to C17 of
the structure.
Forms Of Cholesterol In Human Body
? Cholesterol exists in two forms:
?Free Cholesterol - 30%
(Amphipathic form)
?Cholesterol Ester - 70%
(Non polar form)
Properties Of Cholesterol
? Cholesterol is white or pale yel owish,
crystal ine ,odorless compound.
? Insoluble in water and soluble in organic
solvents like Ether and Chloroform.
Crystals of Cholesterol Rhombic plates
with Notched edges.
? Qualitative Tests For Cholesterol
detection are:
?Liebermann Burchard Reaction
?Salkowski Reaction
?Zak's Reaction
Sources Of Cholesterol
To Human Body
? Exogenous Sources of Cholesterol:
?Animal Origin Food Items
? Endogenous Source Of Cholesterol:
?Obtained In wel fed condition from
Excess Glucose
Dietary Sources Of Cholesterol
?Cholesterol is exclusively
present in animal foods.
? The dietary rich sources of Cholesterol
animal origin foods like:
?Egg Yolk
?Meat
?Milk
?Butter
?Ghee
?Cream
?Remember Cholesterol
is absent in plant origin
food items.
Endogenous Source Of Cholesterol
? Cholesterol Biosynthesized in
human body from Free Excess
Glucose in Liver.
Transportation Of Cholesterol
?Cholesterol in blood is
transported by Lipoproteins:
? Chylomicrons ( Dietary origin)
? LDL (From Hepatocytes to Extra hepatocytes)
? HDL (From Extra hepatocytes to Hepatocytes)
Occurrence and Distribution Of
Cholesterol in the Body
?70 % of Cholesterol associated
with cel ular components
?30 % of Cholesterol is in the
Blood.
? Cholesterol is richly present in Nervous
tissue Brain.
? Other organs containing Cholesterol are:
?Liver
?Adrenal Cortex
?Gonads
?Intestinal Mucosal cel s
?Skin
Functions Of Cholesterol
Depends Upon
Quality and Quantity
? Cholesterol is constituent of biomembranes
of cel
? It give structure, shape and fluidity to them.
Effects on Membrane without Cholesterol
In Cold Environment In Hot Environment
Rigid/ Not Flexible
Too Flexible
Not Fluid
Very Fluid
May Get damage
Not hold Shape
? Cholesterol richly present in
nervous tissue and covers
Myelin sheaths.
? Cholesterol help in nerve
impulse conduction.
? Cholesterol helps in nerve
impulse transmission since:
?It has high dielectric constant.
?It is a poor conductor of heat
and electricity.
Cholesterol Serves Precursor for
Biosynthesis Of Many Steroids
Derivatives of Cholesterol
? Steroids are derivatives of Sterols.
? Chemical Compounds obtained
from Cholesterol are termed as
Steroidal compounds.
? Derivatives of Cholesterol
? Vitamin D (Cholecalciferol)
? Bile acids (Cholic and Chenodeoxycholic acid)
? Bile Salts are obtained from Bile acids.
? Steroidal Hormones
? ACTH
? Mineralocorticoids
? Glucocorticoids
? Sex Hormones: Androgens, Progesterone,
Estrogen and Testosterone
Bile Acids and Bile Salts
Steroids Hormones
Disorders Related To Cholesterol
?Serum Total
Cholesterol level of a
Healthy human body is
150-200 mg%
Hypercholesterolemia
? Causes for Hypercholesterolemia
? High intake of dietary Cholesterol(animal origin) is a
exogenous source of Cholesterol.
? Elevated endogenous Cholesterol biosynthesis
when a very rich Carbohydrates is ingested.
? Defect in Cholesterol transport by Lipoproteins in
blood retains Cholesterol in blood.
Conditions Of Hypercholesterolemia
?Diabetes mellitus
?Obstructive Jaundice
?Nephrotic Syndrome
?Hypothyroidism
? Hypercholesterolemia leads to :
? Deposits of excess of
Cholesterol in blood vessels.
? Atherosclerosis and atheroma
/plaque formation.
? Increased risk of ischemia and
Myocardial infarction and
Stroke.
?Cholesterol Summary
?Cholesterol is exclusively found only in
animals.
?Exogeneous Cholesterol comes from diet
?Endogeneous Cholesterol is biosynthesized
by the Liver from Glucose product Acetyl-
CoA.
?Cholesterol is an important component of
biomembranes, steroidal hormones, bile
acids and Vitamin D
This post was last modified on 05 April 2022