Lesson 3 : Lipids Flashcards
● Lipids with Fatty Acids
● Lipids without Fatty Acids
● Lipids with Fatty Acids
○ Waxes
○ Fats and oils (Triglycerides)
○ Phospholipids
○ Sphingolipids
● Lipids without Fatty Acids
○ Steroids
What is TRIACYLGLYCEROL
● Energy storage lipids.
● Found in Adipocytes (Adipose cells).
● Formed by esterification of glycerol and 3 fatty acids.
process of combining an organic with an alcohol to form an ester with water.
Esterification
The esterification of the triacylglycerol is a
dehydration synthesis reaction where fatty acids and glycerol are combined to form an ester bond and release water.
differentiate simple Triacylglycerol from a mixed Triacylglycerol
● Simple Triacylglycerol - triester formed from esterification of glycerol with 3 identical fatty acids.
● Mixed Triacylglycerol - triester formed from the esterification of glycerol with more than 1 kind of fatty acid.
naturally occurring mixtures of triacylglycerol in which many different triacylglycerol molecules are present which are ______ or _______ at _______ temperature (__C).
Fats
solid / semi-solid
room
25C
naturally occurring mixtures of triacylglycerol in which many different triacylglycerol molecules are present which are ______ at _______ temperature (25C).
oils
liquid
room
differentiate fats from oils
form
composition
melting point
source
fats
Solid at RT
More SFA than UFA
Higher
Animals
oils
Liquid at RT
More UFA than SFA
Lower
Plants, Fish
GOOD FAT VS BAD FAT
SFA (Good or Bad? and Why)
MUFA (Good or Bad? and Why)
PUFA (Good or Bad? and Why)
SFA : Bad, High risk of Heart Disease
MUFA : Good, Low risk of Heart Disease; Low risk of Breast Cancer
PUFA : Bad and Good, Low risk of Heart Disease; High risk of Breast Cancer
OMEGA 3 VS OMEGA 6
Omega 3 ( source and benefits)
Omega 6 (source and benefits)
Omega 3 : Cold water fishes | Low incidence of Heart Disease despite high-fat diet
Omega 6 : Plant Oils | High incidence of Heart Disease if high-fat diet
CHEMICAL REACTIONS
● Esterification or Dehydration Synthesis
● Hydrolysis
● Saponification
● Hydrogenation
● Oxidation
What is Hydrolisis
● Triacylglycerol is split by water and acid (H+ or enzyme catalyst)
● Produce Glycerol and 3 Fatty acids
● Reverse Esterification
Differentiate Acidic and Basic Condition
● Acidic Condition - hydrolysis product of glycerol and fatty acid
● Basic Condition - hydrolysis product is glycerol and fatty acid salts
What is Saponification
● Triacylglycerol undergoes hydrolysis with a strong base and is split into glycerol and salts of fatty acids.
● The salts of fatty acids are “soaps”
● Chemical reaction used to make soaps.
What is Hydrogenation
● Unsaturated compounds react with H2
● Ni (Nickel) or Pt (Platinum) are Catalysts
● C=C bonds -> C-C bonds
○ Double bonds (UFA) break and
become single bonds (SFA).
● Converts cis double bonds to trans double bonds.
have ill effects on blood chemistry similar to those of Saturated Fatty Acids.
Trans fatty acids
What is Oxidation
● C=C double bonds present in Unsaturated Fatty Acids are subject to oxidation with Oxygen (from Air).
● Results to short chain Aldehydes.
● Further oxidation will form short chain carboxylic acids.
What are membrane lipids
Lipids that are structural components of cell membrane.
○ Up to 80% of the mass of the cell membrane can be lipid material.
○ The rest is primarily proteins.
(1) Phospholipid
- Glycerophospholipids
- Sphingophospholipids
(2) Cholesterol
(3)Sphingoglycolipids
- Cerebrosides
- Gangliosides
Most abundant type of membrane lipid.
PHOSPHOLIPIDS
What does Phospholipids contain
contains 1 or more fatty acids, a platform molecule, and a phosphate group with an alcohol.
What is Sphingophospholipids
Contains a fatty acid and a carbohydrate component attached to a sphingosine.
Define Cholesterol
● C27 (carbon) steroid molecule.
○ Composed of 27 carbon linkages.
● Component of cell membranes and precursor for other steroid based lipids.
Lipids that stabilize and disperse water-insoluble materials in aqueous solution
EMULSIFICATION LIPIDS
Two types of Bile Acids
Cholic Acid
Deoxycholic Acid
What is Bile Acids
○ One derivative of cholesterol.
○ It is an emulsifying agent that facilitates the
absorption of dietary lipids in the intestine.
Regulatory lipids that act in the tissue where they are synthesized or at the other locations after transport via the bloodstream.
MESSENGER LIPIDS
Types of Messenger Lipids
Steroid Hormones
- Sex Hormones
- Adrenocorticoids
Eicosanoids
- Prostaglandins
- Thromboxanes
- Leukotrienes
female sex hormones; synthesized in the ovaries and adrenal cortex.
Estrogen
male sex hormones; synthesized in the testis and adrenal cortex.
Androgens
pregnancy hormones; synthesized in the ovaries and placenta.
Progestins
control the balance of Na+ and K+ ions in cells and body fluids.
Mineralocorticoids
control glucose metabolism and counteract inflammation.
Glucocorticoids
involved in many regulatory functions in the body.
Prostaglandin
promote the formation of blood clots by promoting platelet aggregation.
Thromboxane
found in leukocytes and are associated with various inflammatory and allergic responses.
Leukotriene
What are biological waxes
Water insoluble, water repellant lipids with protective coating and lubricating functions.
