2.05 Lipids Flashcards
0
Q
Physical (rather than chemical) properties common to all lipids
A
Insoluble in water
Soluble in nonpolar solvents
1
Q
Groups of compounds related by certain physical properties
A
Lipids
2
Q
Generally compartmentalized to protect themselves from watery environment of cells
A
Lipids
4
Q
Functions of lipids
A
Major source of energy (triglycerides)
Provide hydrophobic barrier in cell membrane (phospholipid)
Coenzyme and regulators
Hormones (cholesterol, steroids)
Mediators of inflammation (prostaglandin, leukotriene)
Electrical insulators in myelinated nerves (sphingomyelin)
5
Q
Classification of lipids
A
Simple
Complex
Derived Lipids
6
Q
Fats/oils: esters of FA with alcohol
Waxes: esters of FA with higher MW monohydric alcohol
A
simple lipids
7
Q
Phospholipids: FA + alochol + phosphoric acid residue
Glycolipids: FA + spingosine + carbohydrate
Sulfolipids, amino lipids,
A
complex lipids
8
Q
Hormones, Ketone bodies, glycerol
A
Derived lipids
9
Q
Long chains of carboxylic acids
Classified according to degree of saturation
A
Fatty acids
10
Q
No double bond
A
Saturated FA
11
Q
One double bond
A
Monounsaturated FA
12
Q
More than one double bonds
A
Polysaturated FA
13
Q
Most frequently used system
Unsystematic, conscise and often unambiguous
A
Trivial nomenclature
14
Q
Mainly named after number of hydrocarbons
Technically clear
IUPAC
A
Systematic names
15
Q
Double-bond indicated by delta x
A
Delta x nomenclature
16
Q
Double bond located from the xth carbon-carbon bond starting from the terminal methyl carbon towards the carbonyl carbon
A
n-x Nomenclature
17
Q
In the from C:D where C is the number of carbon atoms in the FA, and D is the number of double bonds
A
Lipid numbers
18
Q
16:0
A
Palmitic acid
19
Q
18:2; 9,12
A
Linoleic acid
20
Q
18:3; 9,12,15
A
Linolenic acid
21
Q
20:4; 5,8,11,14
A
Arachidonic acid
22
Q
omega 3
A
Linolenic acid
23
Q
omega 6
A
Linoleic acid
24
Q
Linoleic acid and Linolenic acid are considered _____
A
Essential FA
25
Most common FA
Palmitic acid
26
Eicosanoids are derived
Arachidonic acid
27
Major end product of CHO fermentation by rumen organisms
Acetic acid
28
In certain fats in small amounts
| An end product of CHO fermentation by rumen organisms
Butyric, valeric, caproic
29
Spermaceti, cinnamon, palm kernel, coconut oils, laurel, butter
Lauric acid
30
Nutmeg, palm kernel, coconut oils, myrtles, butter
Myristic acid
31
Common in all animal and plant fats
Palmitic acid, stearic acid
32
Geometric isomerism of unsaturated fatty acids
Cis
| Trans fatty acid
33
Hydrocarbons are on the same side of the double bond
Cis FA
34
Hydrocarbons are on the opposite side of the double bond
trans
35
Being more liquid at room temperature
Fluidity
36
Temperature where solids change to liquids
Melting point
37
Relationship of fluidity and melting point
Inversely proportional
38
Increase chain length: fluidity ___, MP ____
Decreases; Increases
39
Decrease saturation; fluidity ____, MP ____
Increases; Decreases
40
Precursor of arachidonic acid
Linoleic acid
41
Deficiency of this essential FA results in decreased vision and altered learning behavior
Linolenic acid
42
Lowers thromboxane production
| Reduced tendency of platelets to aggreagate
Omega fatty acids
43
Esters of the trihydric alcohol glycerol and fatty acids
| Main storage forms of energy in the body
Triglycerides
44
Extremely potent compounds that elicit a wide range of responses, both physiologic and pathologic
Eicosanoids
45
Comprise prostaglandins, thromboxanes, leukotrienes and lipoxins
Eicosanoids
46
Dietary precursor of the eicosanoids
Linolenic acid
47
Immediate precursor of the eicosanoids
| Released from membrane lipids by phospholipase A2
Arachidonic acid
48
Synthesized in platelets and cause vasocontriction and platelet aggregation
Thromboxane (TXA2)
49
Produced by blood vessel walls and are potent inhibitors of platelet aggregation
Prostacyclin (PGI2)
50
Mixture of leukotrienes C4, D4, E4
| Potent constrictors of broncial airway musculature
Slow-reacting substances of anaphylaxis (SRS-A)
51
From arachidonic acid -> cyclooxygenase pathway
Prostaglandin
| Thromboxane
52
From arachidonic acid -> lipoxygenase pathway
Leukotrienes
53
Amphipathic compounds composed of alcohol, diacylglycerol or sphingosine, phosphodiester bond
Phospholipid
54
Predominant lipids of cell membranes
| Degraded by phospholipases
Phospholipid
55
Most abundant phospholipid
| Found in cell membranes
Phosphatidylcholine
| Lecithin
56
Ehanolamine replaces choline
| Also found in cell membranes
Phosphatidylethanolamine
| Cephalin
57
Serine replaces choline
Found in most tissues, cell membrane
Plays a role in apoptosis
Phosphatidylserine
58
Active lipid component of lung surfactant
Inadequate levels lead to Newborn Respiratory Distress Syndrome
Decreases the surface tension of alveoli, enabling them to expand again
Dipalmitoylphosphatidylcholine
Dipalmitoyllecithin
DPPC
59
3 phospholipids in cell membrane
Phosphatidylcholine
Phosphatidylethanolamine
Phosphatidylserine
60
Reservoir for arachidonic acid in the cell membranes
| Source of 2nd messengers
Phospatidylinositol 4,5 BP
61
Degraded by phospholipase C to produce inositol triphosphate and diacylglycerol
IP3 and DAG mediate the release of intracellular calcium and activation of protein kinase C
Phospatidylinositol 4,5 bisphosphate
62
2 molecules of phosphatidic acid esterified through their phosphate groups to an additional molecule of glycerol
Found only in the mitochondria and is essential for its proper function
Only non-protein substance that is considered as antigen
Cardiolipin
63
Part of the glycocalyx located on the outer layer of the cell membrane and functions in cell recognition and cell adhesion
Found in high concentrations in nervous tissue
Glycolipid
64
Sphingosine + fatty acid
Ceramide
65
Ceramide + glucose/galactose
Cerebroside
66
Ceramide + oligosaccharide
Globoside
67
Ceramide + N-acetylneuramic acid
Ganglioside
68
Ceramide + sulfated galactose
Sulfatide
69
Major glycoshingolipid of the brain and the nervous tissue
| Can be converted to sulfogalatosylceramide
Galactosylceramide
70
Present in nervous tissue
| Parts of receptors
Ganglioside
71
Receptor in the human intestine of cholera toxin
GM1
72
Only significant sphingophospholipid in humans where it is an important constituent of the myelin sheath of nerves
Sphingomyelin
73
Similar cyclic nucleus resembling phenanthrene to which cyclopentane ring is attached (4 rings)
Methyl side chains at position 10, 13, and a side chain usually at position 17
Steroid
74
More common and more stable form
chair form
75
Best known steroid
| Very hydrophobic compound composed of 4 fused hydrocarbon rings and 8-membered branched hydrocarbon chain
Cholesterol
76
Cholesterol has a single hydroxyl group located at _____ of the __ ring to which a FA can be attached to form _____
C-3; A; Cholesteryl ester
77
Cholesterol is the precursor of ______
Cell membrane
Vitamin D
Adrenocortical Hormones, Sex Hormones
Bile Acids
78
Active form of vitamin D
1,25-dihydroxycholecalciferol
79
Two primary bile acids
Cholic acid, chenodeoxycholic acid
80
Peroxidation of lipids exposed to oxygen produces ____
| Highly-charged, unstable oxygen molecules with an unpaired electron
Oxygen free radicals
81
Peroxidation of lipids is triggered by _____
Existing free radical
Light
Metal ions
82
Peroxidation of lipids is catalyzed by _____
Heme compounds
| Leukotrienes
83
Oxygen free radicals are counteracted by ____
Anti-oxidants
84
Auto-oxidation
Peroxidation
85
Types of Antioxidants
Preventive antioxidants
| Chain-breaking antioxidants
86
Include catalase and glutathione peroxidase that reacts with ROOH, selenium, chelators
Preventive antioxidants
87
Activates glutathione peroxidase
Selenium
88
Chelators of metal ions
EDTA and DTPA
89
Include superoxide dismutase (SOD) and vitamin E
Chain-breaking antioxidant
90
Partly hydrophilic, party hydrophobic
Amphipathic lipids
91
Examples of amphipathic lipids
FA, phospholipids, sphingolipids, bile salts
92
Nomenclature
| The carbon atoms are numbered, beginning with the _____ as carbon 1
Carbonyl carbon
93
Two classes of phospholipids
Glycerophospholipids (those that contain glycerol)
| Sphingophospholipids (those that contain sphingosine)
94
Simplest phosphoglyceride and the precursor of the other members of the glycerophospholipids
Phosphatidic acid
95
A long chain fatty acid is attached to the amino group of sphingosine though an amide linkage, producing a ______
Ceramide
96
Alcohol group at C-1 of sphingosine is esterified to phosphorylcholine, producing ______
Sphingomyelin
97
Structural component of all cell membranes, modulating their fluidity and, in specialized tissues, precursor of hormones
Cholesterol
98
Ring A of cholesterol has a hydroxyl group at ___
Carbon-3
99
Branched hydrocarbon chain of cholesterol is attached to ____ of the D ring
Carbon-17
100
Ring B has a double bond between ____
C-5 and C-6
