Lipid Chemistry (ppt) Flashcards
1
Q
It is the fraction of any biological material that is 💡insoluble in water but 💡soluble in one or more solvents of low polarity.
A heterogenous group of compounds that include fatty acids, fats and oils, waxes, steroids, phospholipids & sphingolipids.
A
Lipid
2
Q
What are the two major functions of lipids?
A
- Source of energy
2. Important component of cellular structure
3
Q
Classification of Lipids:
A
- Simple lipids
- Complex lipids
- Precursor and derived lipids
4
Q
These are classification of lipids which contains 💡esters of fatty acids with 💡various alcohols
A
Simple lipids
5
Q
It is a simple lipid which contain 💡esters of fatty acids with 💡glycerol
A
Triacylglycerol (triglycerides)
6
Q
These are simple lipids which contain 💡esters of fatty acids with 💡higher molecular weight monohydric
alcohols
A
Waxes
7
Q
These are classification of lipids which contains 💡esters of fatty acids with 💡various alcohols plus an 💡additional functional group.
A
Complex (Compound) Lipids
8
Q
These are complex lipid where there is a 💡phosphate group present.
A
Phospholipids
9
Q
These are complex lipid which contain 💡carbohydrates
A
Glycolipids
10
Q
These are complex lipid which are 💡hybrid molecules of lipids and 💡apoproteins
A
Lipoproteins
11
Q
General Properties of Lipids
A
- Insoluble in water but soluble in one or more solvents of low polarity such as chloroform, acetone, alcohol and benzene
- Esters of fatty acid or capable of forming such esters.
- Utilizable by the living organism.
12
Q
General Properties of Fatty Acids
A
- Monocarboxylic acids with hydrocarbon residues that are acyclic and unbranched.
- Number of carbon atoms is in most cases even.
- May or may not contain double bonds
13
Q
No double bonds
Abundant in animal fats
A
Saturated fatty acids
14
Q
They have double bonds
Abundant in plant and fish oils
A
Unsaturated fatty acids
15
Q
They have one double bond
Ex: Palmitoleic acid (16:1) & Oleic acid (18:1)
A
Monounsaturated fatty acids
16
Q
They have two or more double bonds.
Ex: omega-3 and omega-6 fatty acids
A
Polyunsaturated fatty acids
17
Q
They are derived from eicosa-(20 C) polyenoic fatty acids.
Ex: Prostanoids & leukotrienes
A
Eicosanoids
18
Q
Nutritional Classification of Fatty Acids
A
- Nonessential fatty acids
2. Essential fatty acids
19
Q
These are nutritional fatty acids that 💡can be synthesized in our body.
Ex: saturated fatty acids, palmitoleic acid and oleic acid
A
Nonessential fatty acids
20
Q
These are nutritional fatty acids that 💡cannot be synthesized in our body.
Ex: omega-3 and omega-6 fatty acids
A
Essential fatty acids
21
Q
These are the truly essential fatty acids
A
Linoleic acid and alpha-linolenic acid
22
Q
Examples of Omega-3 fatty acids:
A
a) Alpha-linolenic acid (cis-9,12,15 - octadecatrienoic acid)
b) Timnodonic acid (cis-5,8,11,14,17 – eicosapentaenoic acid)
c) Cervonic acid (cis-4,7,10,13,16,19 – docosahexaenoic acid)
23
Q
Examples of Omega-6 fatty acids:
A
a) Linoleic acid (cis-9,12- octadecadienoic acid)
b) Gamma-linolenic acid (cis-6,9,12 – octadecatrienoic acid)
c) Arachidonic acid (cis-5,8,11,14 – eicosatetraenoic acid)
24
Q
Alternating single and double bond.
A
Conjugated Double Bond
25
Optimal ratio of omega 6 to omega 3 PUFA is between:
1:1 and 4:1
26
-
Methylene interrrupted double bond
27
Fatty acid with 💡more than 12 carbon atoms
Long-chain fatty acids
28
Using the 💡symbol delta plus a superscript number, the reference point is the?
Carboxyl group as C-1
29
Using the 💡symbol omega plus a number beside it reference point is the?
Methyl carbon as C-1
33
It refer to the type of 💡geometric isomerism that occur in unsaturated fatty acids depending on the 💡orientation of the acyl groups around the 💡axes of double bonds.
Cis
| Trans
34
An isomerism formed when the 💡acyl groups are on the 💡same side of the bond; produces a 💡kink
Cis Isomerism
35
An isomerism formed when the 💡acyl groups are on the 💡opposite side.
Trans Isomerism
36
It is a 💡by product of hydrogenation or hardening of natural oils in the manufacture of margarine.
Increased risk of CVD and DM
It raises the levels of TAG and LDL
Trans Fatty Acid
37
Gamma linoleic acid (18:3;6,8,12)
1st digit is the number of carbon atoms
2nd digit is the number of double bonds.
Succeeding number after the 2nd bond is the location of the double bonds.
38
Medium chain fatty acid (rich in Philippines)
Lauric Acid
Coconut oil
39
See anki for the table
Physical Properties of Fatty Acids
40
Deleterious effects of trans fats occur at intakes of:
2-7 g/day
41
Examples of 💡soluble soaps:
Sodium & potassium soaps (e.g. sodium oleate)
42
Examples of 💡insoluble soaps:
Calcium & magnesium soaps (e.g. calcium palmitate)
43
It is a reaction between the 💡carboxyl group of the fatty acid and the 💡hydroxyl group of an alcoholic substance forming an 💡ester compound linked by an 💡ester bond.
Esterification
44
It refers to 💡fatty acid residues.
Acyl group
45
Chemical reactions of fatty acids:
Saponification
Esterification
Reactions of double bonds
Oxidation of the double bonds
46
Only 💡unsaturated fatty acids will give these kind of reactions
Reactions of double bonds
47
Soap formation
Saponification reaction
48
It is a reaction with hydrogen forming 💡saturated fatty acids
It is the principal reaction behind manufacturing of solid shortenings, e.g., margarine
Hydrogenation reaction
49
It is a reaction with 💡halogens like iodine forming 💡iodinated saturated fatty acids
The reaction involved in a chemical test – Iodine number
Halogenation reaction
50
Test to determine the 💡degree of unsaturation
Directly proportional
Iodine number
51
💡In vitro oxidation of double bonds that causes formation of short-chain fatty acid aldehyde producing 💡rancid fat.
Rancidification
52
💡In vivo oxidation of fatty acid that forms ROS (free radicals) that causes the following:
- destroy the integrity of cell membranes
- cause cancer
- aging of tissues
- implicated in degenerative diseases
Lipid Peroxidation (auto-oxidation)
53
These are compounds that 💡inhibit oxidation
Antioxidants
54
It contains 💡three fatty acids are esterified to 💡one glycerol
* Primary ester bonds – 1st and 3rd carbon atoms
* Secondary ester bond – 2nd carbon atom (asymmetric/ chiral)
* Note: Fatty acid in carbon 2 is usually 💡unsaturated
💡Most abundant naturally occurring lipid
💡Most abundant dietary lipid
💡Chief storage form of energy in our body; stored mostly in 💡adipose tissue
¨Adipose tissue under the skin also serve as 💡insulation against low temperatures
¨💡Neutral fat since it does not have any charge
¨Other neutral fats: monoacylglycerol & diacylglycerol
Triacylglycerol (Triglyceride)
55
Salts of fatty acid
| Maybe soluble or insoluble to water
Soaps
56
Classification of Triacylglycerol (TAG)
1. According to number of kinds of fatty acids present
| 2. According to length of hydrocarbon residues of the fatty acids present in TAG
57
According to number of kinds of fatty acids present
1. Simple TAG
| 2. Mixed TAG
58
All three fatty acids are the same e.g., tripalmitin, triolein, triarachidonin
SIMPLE TAG
59
There are 💡two or three different kinds of fatty acids esterified to glycerol
MIXED TAG
60
The mixed TAG are more__ than simple TAG.
common
61
Fatty acid with 💡2 to 4 carbon atoms
Short-chain fatty acids
62
Example of esterification reaction:
Triglyceride synthesis
63
Examples of reaction of double bonds:
Hydrogenation reaction
| Halogenation reaction
64
Advantages of TAG as stored fuel:
1. C atoms are more reduced; yields more energy.
| 2. Hydrophobic unhydrated; does not have to carry extra weight of water.
65
PHYSICAL Properties of TAG:
Depends on the kind of fatty acids esterified to TAG
💡Fats are TAG that are solid at room temp. (Presence of more long chain saturated FA e.g. lard)
💡Oils are TAG that are liquid at room temp. (Presence of more unsaturated FA e.g. cooking oils)
66
* 💡Acid (e.g. HCl) or 💡enzyme (lipase) is used as the hydrolyzing agents
* Products of hydrolysis are 💡free fatty acids & 💡glycerol
* Fatty acids are insoluble in water
* Reaction is 💡reversible
ORDINARY HYDROLYSIS
67
* 💡NaOH or 💡KOH are used as the hydrolyzing agents
* Products of hydrolysis are 💡Na or 💡K soap and 💡glycerol
* The soaps are 💡soluble in water
* Basis of the chemical test – 💡Saponification Number
* Reaction is 💡irreversible
Alkali hydrolysis (saponification reaction)
68
It determines the 💡degree of unsaturation of a given fat or oil.
💡More double bonds, 💡the higher the iodine number.
Iodine number
69
It determines the 💡average length of the carbon chain or 💡molecular weight of the TAG.
Molecular weight is 💡inversely proportional to the saponification number.
Saponification number
70
It measures the 💡volatile fatty acid content of the TAG
💡Short chain TAGs have high RM
Reichert Meissl Number
71
Measures the 💡hydroxy fatty acid content of the TAG
Castor oil has high AN because of its high content of 💡ricinoleic acid, a hydroxylated fatty acid.
Acetyl number
72
Importance of Phospholipids
1. Most abundant component of cell membranes
2. Integral component of plasma lipoproteins
3. Important component of lung surfactant
4. Solubilizes cholesterol in bile
5. Involved in blood coagulation
6. Activator/cofactor of some enzymes
73
Classification of Phospholipids
I. Phosphoglyceride or Glycerophosphatide (A. Phosphatidate; B. Plasmalogen)
II. Phosphosphingoside or sphingomyelin
74
Examples of Phosphatidate:
```
1. Lecithin
2 Cephalin
3. Lipositol
4. Cardiolipin
5. Phosphatidyl glycerol
6. Phosphatidyl serine
```
75
```
Give the chemical names of the following phosphatidate:
1. Lecithin
2 Cephalin
3. Lipositol
4. Cardiolipin
```
1. Phosphatidyl choline
2 Phosphatidyl ethanolamine
3. Phosphatidyl inositol
4. Diphosphatidyl glycerol
76
Most of the TAG found in nature are __.
Long-chain
77
Medium-chain TAG are easier to (1)__ and (2)__.
(1) digest
| (2) absorb
78
It is a glycerophosphatidates which is the most abundant 💡membrane phospholipid.
It is 💡insoluble in acetone.
Lecithin – Phosphatidyl choline
79
It is the most important component of the 💡lung surfactant which 💡prevents the collapse of the lungs at the end of the expiratory phase of respiration
Deficiency will cause 💡respiratory distress syndrome in newborns
Dipalmitoyl phosphatidyl choline
80
It is a glycerophosphatidates which is important component of 💡platelet thromboplastin which is involved in blood coagulation.
Cephalin – Phosphatidyl ethanolamine
81
Hydrolysis of Triacylglycerols
```
Ordinary hydrolysis
Alkali hydrolysis (saponification reaction)
```
82
What is the structural differences between glycerophosphatide and sphingomyelin?
The structural backbone for glycerophosphatide is 💡glycerol and the parent compound is 💡phosphatidic acid.
The structural backbone for sphingomyelin is 💡sphingosine and the parent compound is 💡ceramide.
83
Phosphorylation of inositol will transform lipositol into __.
These are are precursors of 💡second messengers of hormones; cell signaling.
Phosphoinositides
84
It is the 💡simplest glycerophosphatide.
It is the 💡parent compound & basic structure of all phosphatidates
Phosphatidic Acid
85
It is a glycerophosphatidates which is formed by attaching 💡another phosphatidic acid to the glycerol side-chain.
It attaches 💡cytochrome C of the ETC to the inner mitochondrial membrane
It is the only phosphatidate with known 💡immunological property
Decreased in this glycerophosphatidates cause 💡mitochondrial dysfunction in aging, heart failure, hypothyroidism and 💡Barth syndrome (cardioskeletal myopathy)
Cardiolipin
86
It is a phosphoglyceride wherein the side-chain in 💡carbon 1 of phosphatidic acid and an 💡 α,β-unsaturated high molecular weight alcohol
* Forms an 💡OH-OH (ether) linkage with C-1
* Classified as 💡ether lipid
* Found in cardiac and skeletal muscles, brain & liver
* Uses the suffix – 💡dal instead of – dyl
Plasmalogen
87
It is a condition where 💡spingomyelin accumulates in the brain, liver & spleen due to deficiency of 💡spingomyelinase.
Niemann-Pick disease
88
Cephalin is insoluble with?
Ethyl and methyl alcohol
89
Ceramide is attach to sphingosine by what linkage?
Amide linkage with fatty acid
90
Side-chain attached to ceramide is __ by a phosphoester bond
Phosphoryl choline
91
It is a glycerophosphatidates which found in the 💡inner leaflet of the lipid bilayer
Inversion of its location in the membrane is an
💡early sign of apoptosis
Also involved in 💡blood coagulation
Phosphatidyl serine – cephalin-like phosphatidate
92
Fatty acid with 💡6 to 12 carbon atoms.
Medium-chain fatty acids
93
According to length of hydrocarbon residues of the fatty acids present in TAG:
1. Short-chain TAG e.g. tributyrin
2. Medium-chain TAG e.g. 1,2-dilauryl-3-caprylin
3. Long-chain TAG e.g. 1,3-dipalmitoyl-2-linolein
94
It is a glycerophosphatidates where 💡glycerol is the side-chain and is a precursor of 💡cardiolipin
Phosphatidyl glycerol
95
They are lipids with an attached 💡carbohydrate or carbohydrate chain.
They are widely distributed in every tissue of the body, particularly in 💡nervous tissue such as brain.
Glycolipids
96
Glycolipids are found in the __ of the cell membrane as part of the 💡glycocalyx of the cell surface
Outer leaflet
97
O Blood Type
| Immunodominant sugar?
Glucose
98
A Blood Type
N-acetyl galactosamine
99
B Blood Type
Galactose
100
💡Simplest among glycolipids because they contain 💡only one sugar - glucose or galactose
CEREBROSIDES
101
It is abundant in brain
Sphingomyelin
102
All naturally occurring unsaturated fatty acids are __.
Long chain
103
It is the predominant simple glycosphingolipid of 💡extraneural tissues, also occurring in the brain in small amounts.
GLUCOCEREBROSIDES
104
They are 💡complex glycosphingolipids derived from 💡glucosylceramide that contain in addition one or more molecules of a 💡sialic acid.
Gangliosides
105
Krabbe disease enzyme deficiency: ?
○ Abundant galactocerebroside in the 💡white matter of the brain
○ Destroys the protective coating 💡(myelin) of nerve cells in the brain and throughout the nervous system
Galactocerebrosidase (GALC)
106
Also known as ‘Glycolipids’.
GLYCOSPHINGOLIPIDS
107
Metachromatic leukodystrophy disease enzyme deficiency: ?
○ Accumulation of galactosylceramide-3-O-sulfate (sulfatide) in the 💡central and peripheral nervous systems.
Arylsulfatase A (ARSA)
108
Gaucher disease enzyme deficiency: ?
○ Glucocerebrosides accumulate in the liver and spleen of patients
Glucocerebrosidase
109
CEREBROSIDES Examples:
1. GLUCOCEREBROSIDES
| 2. GALACTOCEREBROSIDES
110
GLUCOCEREBROSIDES
GLUCOSYLCERAMIDE
111
Fabry disease enzyme deficiency: ?
○ Accumulation of 💡ceramide trihexoside (globotriaosylceramide)
Alpha-galactosidase A (a-Gal A)
112
● 💡Major sulfolipid of the brain
● Abundant in the 💡white matter
● 3rd carbon atom of Galactose will be sulfated → 💡Galactose 3-SO4
SULFATIDE
113
GALACTOCEREBROSIDES
Galactosylceramide
114
Galactose attached to the ceramide
GALACTOCEREBROSIDES
115
💡Most complex among glycolipids
Ceramide + Sialic Acid or N-acetylneuraminic acid (NANA) + N-acetylglucosamine or N-acetylgalactosamine + D-glucose or D-galactose
GANGLIOSIDES
116
Oligosaccharide + Ceramide =
Globoside
117
When two or more sugars are attached to ceramide, __ is directly attached to ceramide and the succeeding sugar is attached to preceding sugar
Only one sugar
118
It is a receptor for 💡cholera toxin in the intestines
GM1
119
Accumulation of GM1
Generalized gangliosidosis
120
GLOBOSIDE Examples:
Lactosylceramide
| Ceramide trihexoside
121
GANGLIOSIDES is found principally in the?
Brain (concentrated in the ganglion cells)
122
Principal gangliosides:
GM1, GD1, & GT1
123
It is the 💡most common sterol in the membranes of animal cells
Cholesterol
124
Contain 💡8 to 10 carbons in the side-chain 💡(C-27, C-28 and C-29 steroids)
STEROLS
125
Have 💡5 carbons in the side-chain that terminates in a carboxyl group 💡(C-24 steroids)
BILE ACIDS
126
Contain 💡2 carbons in the side-chain 💡(C-21)
PROGESTERONE AND ADRENOCORTICAL
127
It is a 💡precursor for all steroid hormones
Progesterone
128
Tay Sach’s disease enzyme deficiency: ?
○ Accumulation of GM2
Hexosaminidase A
129
No side-chain on 💡C-17
SEX HORMONES
130
Side-chain on 💡C-19
Testosterone
131
Side-chain on 💡C-18
Estradiol
132
Hydroxyl group (-OH) is 💡unesterified
Free cholesterol
133
Hydroxyl group is 💡esterified to unsaturated fatty acid
💡Storage form of cholesterol in tissue
💡Precursor of a large number of equally important steroids
Cholesterol ester
134
● Parent compound of all steroids
| ● Parent ring-structure
CYCLOPENTANOPERHYDROPHENANTHRENE RING
135
Dominant cholesterol in 💡blood
Cholesterol ester
136
Dominant cholesterol in 💡bile
Free cholesterol
137
Primary Bile Acids Examples:
Cholic acid
| Chenodeoxycholic Acid
138
How do steroids differ from one another?
Dependent on the number of carbon atoms in the R group attached to the Carbon 17
○ Convenient way of classifying steroids
139
Vitamin D3
Cholecalciferol (hormone form of calcitriol)
140
An enzyme that will cleave the ester bond, releasing the free cholesterol and fatty acid.
Cholesterol esterase
141
It is the 💡first and principal regulatory step in the biosynthesis of bile acids
7α-hydroxylation of cholesterol
142
It is a 💡microsomal cytochrome P450 enzyme designated CYP7A1 that 💡catalyzed 7α-hydroxylation of cholesterol
Cholesterol 7-hydroxylase
143
Synthesized in the small intestines
Primary Bile Acids
144
Intermediate metabolite in biosynthesis of other steroid hormones
Maintain pregnancy during the first trimester
Involved in menstrual cycle
Drug for threatened abortion
Component of oral contraceptives
PROGESTERONE
145
Secondary Bile Acids Examples:
Deoxycholic acid
| Lithocholic acid
146
Regulate intermediary metabolism
Immunosuppressive and anti-inflammatory action
Play an important role in stress response
CORTISOL
147
Synthesized in the liver
Secondary Bile Acids
148
FUNCTIONS OF BILE ACIDS
1. Aid fat digestion and absorption
2. Facilitate absorption of fat-soluble vitamins (A,D,E,K)
3. Help in solubilization of cholesterol in bile
149
It is formed from testosterone through action of the enzyme 💡5`-reductase.
Dihydrotestosterone
150
Carrier of 💡exogenous (dietary) triacylglycerol in the blood
Synthesized in the 💡small intestine
CHYLOMICRON
151
Regulates water and sodium metabolism
Involved in blood pressure regulation
Promotes tubular reabsorption of the kidney
ALDOSTERONE
152
Normal male sexual development of the embryo
Develops and maintain male secondary sexual characteristics starting from puberty
Important for male fertility
TESTOSTERONE
153
● Carries 💡endogenous cholesterol in the blood
● Carrier of 💡“bad cholesterol”
● Source of cholesterol esters that are deposited in blood vessel walls
● Could lead to 💡atherosclerosis
LOW DENSITY LIPOPROTEIN
154
Normal female sexual development of the embryo
Develops of female secondary sexual characteristics
ESTRADIOL
155
Carries 💡endogenous cholesterol from 💡extrahepatic tissues to the liver
Carrier of 💡“good cholesterol”
Contain the 💡highest amount of phospholipid
HIGH DENSITY LIPOPROTEIN
156
VERY LOW DENSITY LIPOPROTEIN
● Removes triacylglycerol synthesized in the liver
● Prevents the development of fatty liver
● Carries endogenous triglycerides in the blood
● It did not come from the diet and synthesized in the liver
Pre-beta lipoprotein
157
Synthesized by 💡cyclization of C-20 polyenoic fatty acid (e.g. arachidonic acid) through the action of 💡cyclooxygenase enzyme
💡Two double bonds are lost in the reaction
PROSTAGLANDINS/PROSTANOIDS
158
● Formed in the 💡platelets from ARA and EPA
● 💡Stimulates platelet aggregation
● 💡Vasoconstrictor
THROMBOXANE
159
TX from arachidonic acid
TXA2
160
● Produced by 💡blood vessel endothelium from ARA and EPA
● 💡Inhibits of platelet aggregation
● 💡Vasodilator
● 💡Relaxing smooth muscle
PROSTACYCLIN
161
● Formed by the enzyme 💡5-lipoxygenase
● Characterized by presence of 💡3 to 5 double bonds
● Potent chemical mediators of 💡inflammation
LEUKOTRIENES
162
HIGH DENSITY LIPOPROTEIN
Alpha lipoprotein
163
TX from arachidonic acid
TXA2
164
Lipoxygenase vs COX
COX loss of 2 double bonds
| LOX no double bonds are lost
165
Autacoids Examples:
Histamine and serotonin (5-hydroxytryptamine)
166
TX from eicosapentaenoic acid
TXA3
