Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st year (First Year) Biochemistry ppt lectures Topic 66 Lipid Ingestion And Digestion 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.
LIPID METABOLISM
In Health and Diseases
7 Main Human Body Lipid (Forms)
1. Free Fatty acids
2. Cholesterol
3. Triacylglycerol
4. Phospholipid
5. Glycolipids
6. Lipoproteins
7. Eicosanoids
Metabolism of Lipid Forms
Generation, Operation, Destruction
? Sources/Biosynthetic Pathways (Anabolism)
? Functions/Associated Metabolic Pathways
? Breakdown/Degradation Pathways (Catabolism)
? Health= Biomolecules in body present in
regulated, balanced and in ordered
mechanisms.
? Disorders= Biomolecules of body get
dysregulated, imbalanced and interferences
in mechanisms.
Lipid Metabolism Derangement
Is Associated with
Obesity
Metabolic Syndrome
Non Communicable Diseases
Obesity And Metabolic Syndrome
SYNOPSIS
1. DIETARY LIPIDS
?INGESTION
?DIGESTION
?ABSORPTION
?TRANSPORTATION
?UPTAKE BY TISSUES
2. LIPOLYSIS: LIPID CATABOLISM /
Utilization Of Stored TAG
q FATTY ACID OXIDATION
q KETONE BODY METABOLISM
3. LIPOGENESIS:
q LIPID BIOSYNTHESIS
q DE NOVO BIOSYNTHESIS OF FATTY ACIDS
4. LIPOPROTEIN METABOLIM/
TRANSPORTATION OF LIPID FORMS
5. DISORDERS ASSOCIATED TO LIPID
METABOLISM
INGESTION OF DIETARY LIPIDS/
EATING OF DIETARY LIPIDS
?Lipids are chief
constituents of human
food.
Ingestion Of Dietary Lipids
? What quantity and quality of Lipid forms to be
ingested per day?
? Which forms of dietary Lipids ingested from rich
sources ?
? Why to eat dietary Lipids?
What quantity and
quality of Lipids to be
ingested per day?
In What
Amount (Quantity) Dietary Lipids to be
Eaten?
? Daily consumption of dietary Lipids
by human beings varies and
depends upon:
?Dietary habits of an individual
?Economic status of a family
RDA OF DIETARY LIPIDS
?Per day quantity of dietary
Lipids for an adult individual
is:
?20-35% of Calorie need
?50-80 grams/day of dietary
Lipids
In What Form (Quality) Dietary Lipids
are ingested?
FORMS AND SOURCES OF
INGESTED DIETARY LIPIDS
? Dietary ingested Lipids contain fol owing
forms of Lipids:
?Triacylglycerol (TAG):Principal dietary
Lipid form ingested - 98%.
?Phospholipid
?Cholesterol Ester
?Fat soluble Vitamins: are soluble in Fat
hence associated with fatty foods.
Quality Of Dietary Lipids To be ingested
? Natural
? PUFA of Cis Form
? Omega 3 and Omega 6
? PUFA:MUFA:SFA 1:1:1 ratio
Avoid Trans Fats
As they are detrimental to Health
? Sources of dietary Lipids
should be free from Trans
Fatty acids/less than 1%.
? Trans Fatty acids are not
readily metabolized by
human body.
? Trans Fats increases the
risk of Atherosclerosis.
Dietary Rich Sources Of Lipids
? Obtained from both foods of
Plant and Animal origin.
Forms Of Fat in Food Sources
Visible Fat
Butter, Margarine, Salad oils and
dressing, Shortening Fat Meat
Invisible Fat
Cheese, Cream portion of
homogenized milk, Egg yolk, Nuts,
Seeds, Olives.
Sources Of Plant Lipids
q Plant Oils: Peanut ,Safflower
,Sunflower, Olive, Mustard Oils,
Margarine etc.
qNuts: Peanuts , Walnuts , Cashew
,Almonds, Sesame ,Pine etc
Sources Of Animal Lipids
?Milk and Milk products
?Egg Yolk
?Sea foods ?Fish, Shell fish
?Animal-Fat ,Meat , Liver and
Brain
Rich Dietary Sources of PUFAs
Why To Eat Dietary Lipids?
OR
Importance Of Ingesting
Dietary Lipids
Importance Of Ingesting Dietary Lipids:
? TAG (predominantly ingested) - secondary source of
energy for body tissues.
? Source of Essential Fatty acids/PUFAs-structural
components of tissues.
? Source of Fat Soluble Vitamins- Vitamin A,D,E and K
associated with Fatty foods.
? Improve taste of recipes.
? Increase palatability and satiety value.
? Thus daily consumption of
dietary lipids is essential for
? Maintenance of normal
?Health
?Growth
?Reproduction
Digestion Of Dietary Lipids In GIT
Digestion of Dietary Lipids
Is
Cleavage Of Ester Bonds
Present In Various
Complex /Unabsorbable Lipid Forms
By
Lipases/Lipolytic Enzymes
In
Different Parts Of GIT
Prerequisites for Lipid Digestion
? GIT Hormones
? Optimum pH
? Emulsifiers
? Emulsification
? Lipid Digesting Enzymes- Lipases
Gastrin
Chyme stimulates
Cholecystokinin (CCK)
Secretin
to release bile from
gallbladder and
Pancreas for Pancreatic
juice.
Enterogastrone
?Cholecystokinin (CCK)
and Secretin
?Stimulates the:
Gal bladder to contract
and release bile.
Mechanism Of Lipid Digestion
in Different Parts of GIT
Insignificant Lipid Digestion
Occurs in Mouth and Stomach
? Though Salivary juice contains
Lingual Lipase and Gastric juice
contains Gastric Lipase .
? Digestion of dietary Lipids in
mouth is negligible and stomach
is~10% of TAGs are hydrolyzed
Insignificant Digestion Of Lipids In Mouth and
Stomach Due to:
?No optimal pH of salivary and gastric juices
?No optimal activity of Enzyme Lipases
(Optimal pH range 6-8)
?No Emulsification Process in Mouth and
Stomach
?Dietary Lipids (insoluble form) when not
emulsified
?Do not have contact with polar and soluble
forms of Lipases present in the aqueous
phase of salivary and gastric juices.
?There is no cleavage of Ester bonds of Lipid
structures in salivary and gastric juices
?Insignificant digestion of Lipids in mouth
and stomach.
Significant and Complete
Digestion
Of Dietary Lipids
Occurs In
Smal Intestine
In presence of Bile after
Emulsification
Requirements
for
Emulsification
To Form Emulsions
Essential y Requires
Presence Of Bile
In Smal Intestine
For Lipid Digestion and
Absorption
? Bile is a greenish
fluid produced in
Liver.
? Concentrated and
stored in Gal
bladder.
? Carried through bile
duct
? Later secreted in
Smal intestine via
Common Bile Duct
(CBD)
Composition Of Bile
? Bile is an
Alkaline solution
? Composed of:
?Bile Salts
(Surfactant)
?Bilirubin
(Bile Pigment)
?Bile acids
?Cholesterol
?Lecithin
Bile Acids Derived From Cholesterol
?Name Of Bile
salts :
?Sodium
Glycocholate
?Sodium
Taurocholate
Role Of Bile Salts In Formation of
Emulsions During Emulsification
? Emulsifying agents/Emulsifiers:
?Emulsifying Agents/Surfactants:
? Bile Salts
(Sodium Glycocholate, Sodium Taurocholate)
? Amphipathic Lipids
(Phospholipids)
?Bile salts have detergent
like action
?Bile salts serve as :
? Emulsifying agents
? Responsible for fat Emulsification
? Bile salts and dietary Amphipathic
Lipids by their detergent like
action:
?Reduces surface tension
?Increases surface area of Fats/Oil
and make them miscible with
aqueous phase.
? Emulsions bring non polar
dietary Lipids in close
contact with Lipid digesting
Enzymes present in aqueous
phase of intestinal juices.
What Is Emulsification?
Emulsification
Takes Place In Smal intestine
Which
Initiate and Completes
Significant Digestion of
Dietary Lipids
Emulsifiers brings out Emulsification
and forms Emulsions
?Emulsification is an Essential
Prerequisite Physicochemical
Process
?Which forms Emulsions from
dietary ingested Lipids.
? Emulsification takes place in the
lumen of smal intestine.
? Emulsification process occur
before digestion of dietary Lipids.
? During the process of
Emulsification there is
dispersion of large droplets
of Fats/Oils
? Into smal , miscible droplets
which are termed as
Emulsions.
?Emulsions have non polar
lipids (TAG) in center
?Covered with a peripheral
layer of Bile salts and
Amphipathic Lipids.
Emulsions formed by Bile salts, Triacylglycerols and pancreatic lipase.
Emulsification Forming Emulsions
Significance Of Emulsification
? Emulsification facilitate digestion of dietary
Lipids in smal intestine by:
?Reduces surface tension, increasing surface
area of Lipids
?Forms Emulsions
?Improves miscibility of non polar Lipids TAG
in aqueous phase.
?Brings contact of dietary Lipids with Lipid
digesting enzymes.
?Facilitates cleavage of Ester bonds of
dietary Lipids.
This post was last modified on 05 April 2022