Flashcards in chem lab - lipids Deck (103):
1
hydrophobic isoprenoids
A, D, E, K
2
are PUFAs
-must be provided in our diet because EFAs cannot be biosynthesized
EFAs
3
1. Fatty-acid related :
fatty acid/prostaglandins, fatty acid esters, sterol esters, lipoconjugates
4
2. Hydrolyzable/saponifiable:
fatty acid esters, sterol esters, lipoconjugates
5
-aliphatic, acyclic, unbranched
fatty acids
6
fatty acid synthesis in humans:
liver and lactating mammary glands
7
most naturally occurring FA contain odd or even no. of C atoms
EVEN
8
-no C=C
-CnH2n+1 COOH
-___anoic acid
saturated
9
-CnH2n-1COOH
- ____enoic acid
unsaturated
10
– natural configuration of C=C
Cis configuration
11
-introduces a kink, allowing a bend
-bend disrupts alignment of lipid → semi-fluid
Cis configuration
12
2 EFAs to humans
1. Linoleic acid –
2. Linolenic acid
13
precursor of arachidonic acid
linoleic
14
– precursor of PGs
-becomes essential if linoleic acid is missing
Arachidonic acid
15
– alkali salts of Fa
-formed by saponification
-amphipathic
-nonpolar + dirt, polar + water (micelle)
4. Soaps
16
5. Halogens add to C=C via
AE
17
– resistant to oxidation outside the body
saturated FA
18
slowly but spontaneously oxidized by oxygen in air
-becomes rancid (formation of short chain aldehydes)
USFA-
19
-derived from linoleic acid (or arachidonic acids) forming eicosanoids
PROSTAGLANDINS
20
-cyclopentane ring, 2 side chains, carboxyl group in one side chain
PROSTAGLANDINS
21
-participate in wound-healing process
PROSTAGLANDINS
22
PAIN MEDIATORS
PROSTAGLANDINS
23
-esters formed between a fatty acid (CA) and glycerol (trihydric alcohol)
Acyglycerols or glycerides
24
-3 Fatty acids + glycerol
TRIGLYCERIDES
25
-neutral fats or neutral oils
TRIGLYCERIDES
26
-most widespread
TRIGLYCERIDES
27
-most abundant lipids in animals (function: food store)
TRIGLYCERIDES
28
Hydrolysis of tripalmitin or 1,2,3-tripalmitoyl-sn-glycerol
• 1 mole of glycerol
• 3 moles of palmitic acid
29
Hydrolysis of palmitostearoolein or 1-palmitoyl-2-stearoyl-3-oleoyl-sn-glycerol
• 1 mole glycerol
• 1 mole palmitic acid
• 1 mole stearic acid
• 1 mole oleic acid
30
Hardening of oils is due to what reaction
-hydrogenation of C=C → saturated compounds
31
Drying oils s due to what reaction
-action of O2 in air forms hydroperoxides
32
-composed of an alcohol + diacylgycerol or sphingosine
phospholipids
33
-phospholipids with glycerol
phosphoglycerides/glycerophosphatides/phosphoacylglycerol
34
all phosphoglycerides contain
phosphatidic acid
35
backbone of phosphoglycerides
phosphatidic acid
36
– alcohol-soluble, acetone-insoluble
lecithin
37
-most abundant phosphoglyceride
lecithin
38
-white waxy substance
-used as an emulsifier
-predominantly phosphatidyl choline
lecithin
39
4nry amine alcohol
Choline-
40
Hydrolysis of lecithin
• 2 moles FA
• 1 mole phosphoric acid
• 1 mole choline
• 1 mole glycerol
41
– alcohol-insoluble, acetone-insoluble
-abundant in nerve and brain tissues
-mixture of phosphatidyl ethanolamine (predominant) or phosphatidyl serine
Cephalin
42
Hydrolysis of cephalin
• 1 mole ethanolamine or serine
• 2 moles FA
• 1 mole phosphoric acid
• 1 mole glycerol
43
- derivatives of perhydrocyclopentanophenanthrene
steroids
44
true terpenes
steroids
45
-synthesized in living systems from isoprene via squalene
steroids
46
-steroids with one or more OH groups (alcohols)
Sterols
47
– 27 C atoms
-2ndary alcohol
cholesterol
48
-derived from B-squalene (triterpene)
cholesterol
49
-major constituent of gallstone from which it was first isolated
cholesterol
50
-major sterol in animal tissues
cholesterol
51
1. Component of cell membrane
2. Precursor of bile acids, steroid hormones, vitamin D
cholesterol
52
– plays a central role in regulation of body’s cholesterol
Liver
53
– plasma cholesterol in esterified form
-hydrolysable
Cholesteryl esters
54
-hydrolysis of cholesteryl esters
1 mole cholesterol, 1 mole FA
55
-control 2o sex characteristics, reproductive cycle, growth and development of accessory reproductive organs
1. Sex hormones
56
produces testosterone (androgen that stimulates spermatogenesis and development of male 2o characteristics) in Leydig cells, stimulated by LH
-testis
57
produce estrogen (menstrual cycle, 2o sex characteristics) and progesterone (secretory phase of uterus and mammary glands, nidation, maturation of fertilized ovum)
-ovaries:
58
-control water and electrolyte balance, carbohydrate and protein metabolism
2. Adrenocorticoid hormones
59
secreted when ACTH is stimulated
-increased gluconeogenesis, anti-inflammatory action, protein breakdown
Cortisol –
60
-secretion induced by Na/K ratio and by angiotensin
-function: stimulates renal reabsorption of Na and excretion of K
Aldosterone
61
3. Vitamin D – lipid soluble, nonpolar, hydrophobic
-derived from isoprenoids or terpenoids
vit D
62
Vit D2
ergocalciferol
63
Vit D3
cholecalciferol
64
-most toxic of all vitamins, slowly metabolized
vit D
65
watery mixture of organic and inorganic compounds, contain lecithin and bile salts
-Bile:
66
pKa = 6, not fully ionized
bile acids
67
provide the only mechanism for cholesterol excretion
bile salts
68
emulsifier
bile acids, soap, lecithin
69
-multiples of isoperene units
-where most of the plant’s pleasant odors come from
TERPENOIDS OR ISOPRENOIDS
70
– a triterpene
-precursor of cholesterol
-all trans-configuration
Squalene or β-squalene
71
-collective term for retinol, retinoic acid, retinal, β-carotene (tetraterpene)
-found in green vegetables, fruits, eggs
-stored in liver
vit A
72
-function: essential for vision, growth and reproduction
-deficiency: night blindness, xerophthalmia
vit A
73
– visual pigment consisting of retinal and opsin
Rhodopsin
74
rhodopsin consists of (2)
retinal and opsin
75
-found in vegetable oils, egg
-naturally occurring tocopherols
Vitamin E
76
most active tocopherol
alpha-tocopherol
77
-function: natural antioxidant
Vitamin E
78
-least toxic of fat-soluble vit
Vitamin E
79
-in cabbage, cauliflower, spinach, egg yolk
-stored in liver
-absorbed in presence of bile acid
Vitamin K
80
parent cpd of Vitamin K
menadione, vit K3
81
-function: Koagulations vitamin
-large doses: haemolytic anemia, jaundice
VIT K
82
-first isolated from the brain
SPHINGOLIPIDS
83
-2nd most abundant class of lipids
SPHINGOLIPIDS
84
-found in cell membrane of nerve and brain tissues
SPHINGOLIPIDS
85
-backbone compound of sphingolipids
ceramide
86
phospholipids with sphinosine
Sphingosine Phosphatides –
87
– abundant in brain and nerve tissues
-zwitterionic, amphipathic
Sphingomyelin
88
– accumulation of sphingomyelin in large amounts in brain, liver, spleen
Niemann-Pick disease
89
Hydrolysis of sphingomyelin:
•
1 mole fatty acid
• 1 mole sphingosine
• 1 mole phosphoric acid
• 1 mole choline
90
-sphingolipids with carbohydrates, without phosphorus
-primary OH group is hydroxylated
Sphingosine glycosides or glycosphingolipids
91
sphingolipid found in white matter of brain
Cerebroside or galactosyl ceramide –
92
– glucose replaced galactose
Gaucher’s disease
93
Hydrolysis of cerebrosides
• 1 mole of D-galactose
• 1 mole sphingosine
• 1 mole FA
94
– also found in brain
-OH of C3 is esterified to a sulphate group
Cerebroside sulfates/Sulfatides
95
– glycosphingolipids with sugar sialic acid
Gangliosides
96
number of grams of I2 absorbed by 100 g lipid sample
Iodine number-
97
– number of mg KOH needed to neutralize free fatty acids or fatty acids released as result of hydrolysis in 1 g lipid sample or fatty acid released
Acid Value
98
-↑ acid number, ______
↑tendency to be rancid
99
-measure of acidity, measure of the tendency to become rancid
Acid Value
100
– number of mg KOH required to saponify the ester in 1 g of lipid sample
Ester Number
101
Acid Number + Ester Number =
Saponification Number
102
number of mg KOH required to neutralize free fatty acids or fatty acids released as a result of hydrolysis and to saponify esters contained in1g lipid sample
Saponification Number-
103