Ch 21 - Lipids Of Physiologic Significance Flashcards
1
Q
The _______ are heteregoneous group of compounds, including FATS, OILS, STEROIDS, WAXES amd related compounds, that are related more by their physical than by their chemical properties.
A
Lipids
2
Q
Lipids have the common property of being _________ in water and _________ in nonpolar solvents such as ETHER, CHLOROFORM and BENZENE.
A
Insoluble
Soluble
3
Q
Dietary supplementation with _______________ is believed to have beneficial effects in a number of chronic diseases, including cardiovascular disease, rheumatoid arthritis and dementia.
A
Long chain omega-3 fatty acids
4
Q
Nonpolar lipids acts as _____________, allowing rapid propagation of depolarization waves along myelinated nerves.
A
Electrical insulator
5
Q
Lipids are transported in the blood combined with proteins in _________________.
A
Lipoprotein practicles
6
Q
_______________ include FATS and WAXES which are esters of fatty acids vith various alcohols.
A
Simple lipids
7
Q
Esters of fatty acids with GYLCEROL.
A
Fats
8
Q
______ are fats in the liquid state.
A
Oils
9
Q
Esters of fatty acids with higher molecular weight monohydric alcohols.
A
Waxes
10
Q
______________ are esters of fatty acids containing groups in addition to an alcohol and one or more fatty acids.
A
Complex lipids
11
Q
Lipids containing in addition to fatty acids and an alcohol, a phosphoric acid residue. They frequently have nitrogen-containing bases (e.g choline).
A
Phospholipids
12
Q
In many phospholipids the alcohol is GLYCEROL ______________ but in _________________ it is SPHINGOSINE, which contains an amino group.
A
Glycerophospholipids
Sphingophospholipids
13
Q
Lipids containing a fatty acid, sphingosine and carbohydrate.
A
Glycolipids (Glycosphingolipids)
14
Q
Because they are uncharged, acylglycerols (glycerides), cholesterol and cholesteryl esters are termed ____________.
A
Neutral lipids
15
Q
_______________ are alipathic carboxylic acids.
A
Fatty acids
16
Q
Fatty acids occur in the body mainly as ________ in natural fats and oils, but are found in the unesterified form as ______________, a transport form in the plasma.
A
Esters
Free fatty acids
17
Q
True or False:
Fatty acids that occur in natural fats usually contain an even number of carbon atoms.
A
True
18
Q
Containing one or more double bonds.
A
Unsaturated
19
Q
Containing no double atoms
A
Saturated
20
Q
The most frequently used systematic nomenclature names the fatty acid after the hydrocarbon with the same number and arrangement of carbon atoms, with -_____ being substitued for the final -e. (___________ system).
A
-oic
Genevan system
21
Q
Saturated acids end in -_____ for example OCTANOIC ACID and unsaturated acids with double bonds end in -_______ for example OCTADECENOIC ACID.
A
- anoic
- enoic
22
Q
Carbon atoms are numbered from the ___________________.
A
Carboxyl carbon (carbon no. 1)
23
Q
The carbon atoms adjacent to the carboxyl carbon (nos. 2, 3, 4) are also known as the _______________ respectively.
A
Alpha, beta and gamma carbons
24
Q
The terminal methyl carbon is known as the _____________.
A
w-or n-carbon
25
Major end product of carbohydrate fermentation by rumen organisms.
Acetic
26
In certain fats in small amounts (especially butter). An end product of carbohydrate fermentation by rumen organisms.
Butyric
27
Spermaceti, cinnamon, palm kernel, coconut oils, laurels and butter.
Lauric
28
Nutmeg, palm kernel, coconut oils, myrtles , butter
Myristic
29
Common in all animal and plant fats
Palmitic
30
18 Carbon atoms
Stearic
31
16 C atoms
Palmitic
32
14 C atoms
Myristic
33
12 C atoms
Lauric
34
6 C atoms
Caproic
35
5 C atoms
Valeric
36
4 C atoms
Butyric
37
2 C atoms
Acetic
38
Containg one double bond.
Monounsaturated
39
Containing two or more double bonds.
Polyunsaturated
40
These compounds, derived from eicosa (20-carbon) polyenoic fatty acids comprise the PROSTANOIDS, LEUKOTRIENES (LTs), and LIPOXINS (LXs).
Eicosanoids
41
______________ exist in virtually every mammalian tissue, acting as local hormones; they have important physiologic and pharmacologic activites.
Prostaglandins
42
They are synthesized in vivo by cyclization of the center of the carbon chain of 20-carbon (eicosanoic) polyunsaturated fatty acids to form a cyclopentane ring.
Prostaglandins
43
The _________________ have the cyclopentane ring interrupted with an oxygen atom (oxane ring).
Thromboxanes
44
The LEUKOTRIENES and LIPOXINS are a third group of eicosanoid derivatives formed via the ________________.
Lipoxygenase pathway
45
___________________ cause bronchoconstriction as well as being potent inflammatory agents, and play a part in asthma.
Leukotrienes
46
Most naturally occuring unsaturated fatty acids have ___________.
cis double bounds
47
The carbon chains of unsaturated fatty acids form a _____________ when extended at low temperatures.
Zigzag pattern
48
At higher temperatures, some bonds ________, causing chain shortening, which explains why biomembranes become thinner with increases in temperature.
Rotate
49
A type of _______________ occurs in unsaturated fatty acids, depending on the orientation of atoms or groups around the axes of double bonds, which do not allow rotation.
Geometric isomerism
50
If the acyl chains are on the SAME SIDE of the bond, it is -____ as in oleic acid; if on OPPOSITE SIDES, it is ______- as in elaidic acid.
Cis
Trans
51
Double bonds in naturally occuring unsaturated long-chain fatty acids are nearly all in the ____ configuration, the molecules being "bent" _____ degrees at the double bond.
Cis
120
52
Thus, oleic acid has a _______, whereas elaidic acid remains ____.
V shape
Straight
53
__________, with 4 cis double bonds, is bent into a U shape.
Arachidonic acid
54
True or False
DECREASE in the number of cis double bonds in a fatty acid leads to a variety of possible spatial configurations of the molecule.
False
INCREASE
55
____________ are presemt in certain foods, arising as a by-product of the saturation of fatty acids during hydrogenation or "hardening" of natural oils in the manufacture of margarine.
Trans fatty acids
56
True or False:
Physical and physiologic properties of fatty acids reflect CHAIN LENGTH and DEGREE OF UNSATURATION.
True
57
The melting points of even-numbered fatty acids _______ with chain length and _________ according to unsaturation.
Increase
Decrease
58
In nearly all fats
Palmitoleic
59
Possibly the most common fatty acid in natural fats; particularly high in olive oil
Oleic
60
Hydrogenated and ruminant fats
Elaidic
61
Corn, peanut, cottonseed, soy bean and many plant oils
Linoleic
62
Some plants, eg. oil of evening primrose, borage oil; minor fatty acid in animals
Gamma-linolenic
63
Found in animal fats, important component of phospholipids in animals.
Arachidonic
64
Important component of fish oils, eg, cod liver, mackerel, menhaden, salmon oils
Timnodonic
65
Fish oils, algal oils, phospholipids in brain
Cervonic
66
A triacylglycerol containing three saturated fatty acids of 12 carbons or more is _______ at body temperature, whereas if the fatty acid residues are polyunsaturated, it is ___________.
Solid
Liquid to below 0 degree.
67
____________ which must be fluid at all environmental temperature, are more unsaturated than storage lipids.
Membrane lipids
68
True or False
Lipids in tissues that are subject to cooling, for example, in hibernators or in the extremities of animals, are also more unsaturated.
True
69
Found in plant oils.
Alpha-linolenic (ALA)
70
Found in fish oil
Eicosapentaenoic (EPA)
71
Found in fish and algal oils
Docosahexaenoic (DHA)
72
_____________ are the main storage forms of fatty acids.
Triacylglycerols (Triglycerides)
73
The _____________ are esters of the trihydric alcohol and fatty acids.
Triacylglycerols
74
______ and _________ wherein one or two fatty acids are esterified with glycerol
Mono- and diacylglycerols
75
Carbon __ & __ of glycerol are not identical.
1 & 3
76
To number the carbon atoms of glycerol unambigously, the ___________ system is used.
-sn (stereochemical numbering)
77
Glycerol is always phosphorylated on sn-3 by glycerol kinase to give _____________ and not gylcerol-1-phosphate.
Gylcerol-3-phosphate
78
Many phospholipids are derivatives of _________________, in which the phosphate is esterified with one OH group of glycerol and the other two OH groups are esterified to two long chain fatty acids.
Phosphatidic acid
79
_____________ is important as an intermediate in the synthesis of triacylglycerols as well as phosphoglycerols but is not found in any great quantity in tissues.
Phosphatidic acid
80
____________ containing CHOLINE are the most abundant phospholipids of the cell membrane and represent a large proportiom of the body's store of choline.
Glycerophospholipids
81
Commonly called LECITHINS.
Phosphatidylcholines
82
_______ is important in nervous transmission and as a store of labile methy groups.
Choline
83
___________ is a very effective surface-active agent and a major constituent of the surfactant preventing adherence, due to surface tension, of the inner surfaces of the lungs.
Dipalmitoyl lecithin
84
Most phospholipids have a SATURATED acyl radical in the ________ position but an UNSATURATED radical in the _____ of glycerol.
sn-1
sn-2
85
Phosphatidylserine also plays a role in ___________.
Apoptosis
86
____________ are found in the outer leaflet of the cell membrane lipid bilayer and are particularly abundant in specialized areas of the plasma membrane known as __________.
Sphingomyelins
Lipid rafts
87
_____________ are also found in large quantities in the MYELIN SHEATH that surrounds nerve fibers
Sphingomyelins
88
They are believed to play a role in cell signaling and in apoptosis.
Sphingomyelins
89
True or False:
Sphingomyelins contain glycerol, and on hydrolysis they yield a fatty acid, phosphoric acid, choline and sphingosine.
False:
NO GLYCEROL
90
The combination of sphingosine plus fatty acid is known as _________, a structure also found in the glycosphingolipids.
Ceramide
91
______________ is a precursor of second messengers.
Phosphatidylinositol
92
The inositol is present in phosphatidylinositol as the stereoisomoer, ____________.
Myoinositol
93
Phosphorylated phosphatidylinositols or ______________ are minor components of cell membranes but play an important part in CELL SIGNALING and MEMBRANE TRAFFICKING.
Phosphoinositides
94
Phosphatidylinositol 4,5-biphosphate (PiP2) is cleaved into _________ and ________ upon stimulation by a suitable hormone agonist, and both of these act as internal signals or second messengers.
Diacylglycerol and inositol tris-phosphate
95
___________ is a major lipid of mitochondrial membranes.
Cardiolipin
96
Phosphatidic acid is a precursor of phosphatidylglycerol, which in turn gives rise to ___________.
Cardiolipin
97
This phospholipid is found only in mitochondria and is essential for the mitochondrial function.
Cardiolipin
98
_________ cardiolipin levels or alterations in its structure or metabolism cause mitochondrial dysfunction in aging and in pathological conditions including HEART FAILURE, HYPOTHYROIDISM and BARTH SYNDROME (Cardioskeletal myopathy).
Decreased
99
___________ are intermediates in the metabolism of phosphogylcerols.
Lysophospholipids
100
These are phosphoacylglycerols containing only one acyl radical, for example _______________, important in the metabolism and interconversion of phospholipids.
Lysophosphatidylcholine (lysolecithin)
101
It is also found in oxidized lipoproteins and has been implicated in some of their effects in promoting atherosclerosis.
Lysophospholipids
102
These compounds constitue as much as 10% to 30% of the phospholipids of brain and heart.
Plasmalogens
103
Structurally, the plasmalogens resemble _______________ but posess an ether link on the sn-1 carbon instead of the ester link found in acylglycerols.
Phosphatidylethanolamine
104
Typically, the __________ is an unsaturated alcohol.
Alkyl radical
105
It has been suggested that they may have a protective effect against reactive oxygen species.
Plasmalogens
106
______________ are important in nerve tissues and in the cell membrane.
Glycolipids (Glycosphingolipids)
107
________ 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
108
Glycolipids occur particularly in the outer leaflet of the plasma membrane, where they contribute to cell surface carbohydrates which form the _________.
Glycocalyx
109
The major glycolipids found in animal tissues are _______________.
Glycosphingolipids
110
True or False:
Glycosphingolipids contain ceramide and one or more sugars.
True
111
___________ is a major glycosphingolipid of brain and other nervous tissue, found in relatively low amounts elsewhere.
Galactosylceramide
112
Galactsylceramide contains a number of characterstic _____ fatty acids for example, cerebronic acid.
C24
113
Galactosylceramide can be converted to ___________ which has a sulfo group attached to the O in the three position of galactose and is present in high amounts in ________.
Sulfogalactosylceramide (sulfatide)
Myelin
114
____________ resembles galactosylceramide, but the head group is GLUCOSE rather than galactose.
Glucosylceramide
115
It is the predominant simple glycosphingolipid of extraneural tissues, also occuring in the brain in small amounts.
Glucosylceramide
116
_________ are complex glycosphingolipids are derived from glucosylceramide that contain in addition one or more molecules of a sialic acid.
Gangliosides
117
______________ is the principal sialic acid found in human tissues.
Neuraminic acid
118
True or False:
Gangliosides are absent in nervous tissues
False:
Gangliosides are also present in nervous tissues in high concentration.
119
They function in cell-cell recognition and communication and as receptors for hormones and bacterial toxins such as cholera toxin.
Gangliosides or neuraminic acid ???
120
The simplest ganglioside found in tissues is _____, which contains ceramide, one molecule of NeuAc and one molecule of galactose.
GM3
121
_____, a more complex ganglioside derived from GM3, is of considerable biologic interest as it is known to be the receptor in human intestine for cholera toxin.
GM1
122
Other gangliosides can contain anywhere from one to five molecules of sialic acid, giving rise to _______________.
di-trisialogangliosides
123
All steroids have a similar cyclic nucleus resembling ______________ (rings A, B and C) to which a cyclopentane ring (D) is attached.
Phenanthrene
124
It is important to realize that in structural formulas of steroids, a simple hexagonal ring denotes a completely ____________ with all valences satisfied by hydrogen bonds unless shown otherwise; it is not a benzene ring.
Saturated six-carbon ring
125
If the compound has one or more hydroxyl groups and no carbonyl or carboxyl groups, it is a ________ and the name terminates in -ol.
Sterol
126
Each of the six-carbon rings of the steroid nucleus is capable of existing in the three-dimensional conformation either of a "______" or a "_________".
Chair
Boat
127
In naturally occuring steroids, virtually all the rings are in the _______ form, which is the more stable conformation.
Chair
128
___________ is widely distributed in all cells of the body but particularly in nervous tissue.
Cholesterol
129
It is a major constituent of the plasma membrane and of plasma lipoprotein.
Cholesterol
130
Cholesterol is found as _____________, where the hydroxyl group on position 3 is esterified with a long-chain fatty acid.
Cholesteryl ester
131
_____________ is a precursor of Vitamin D.
Ergosterol
132
__________ occurs in plants and yeast and is important as a dietary source of Vitamin D.
Ergosterol
133
When irradiated with ultraviolet light in the skin, ring B is opened to form _______________ in a process similar to the one that forms _____________ from 7-dehydro-cholesterol in the skin.
Vitamin D2
Vitamin D3
134
Although not steroids, ____________ are related because they are synthesized, like cholesterol, from five-carbon isoprene units.
Polyprenoids
135
_____________ participates in the respiratory chain in mitochondria.
Ubiquinone
136
The long-chain alcohol ___________, which takes part in glycoprotein synthesis by transferring carbohydrate residues to aspargine residues of the polypeptide.
Dolichol
137
The deleterious effects are considered to be caused by _____________, molecules that have unpaired valence electrons, making them highly reactive.
Free radicals
138
Free radical containing oxygen are termed ________________.
Reactive oxygen species (ROS)
139
These are produced during peroxide formation from fatty acids containing methylene-interrupted double bonds, that is, those found in the naturally occuring polyunsaturated fatty acids.
ROS
140
______________ is a chain reaction providing a continuous supply of ROS that initiate further peroxidation and thus has potentially devastating effects.
Lipid peroxidation
141
The whole process can be depicted as follows:
1. Initiation
2. Propagation
3. Termination
142
To control and reduce lipid peroxidation, both humans in their activities and nature invoke the use of ______________.
Antioxidants
143
Are antioxidants used as food additives:
1. Propyl gallate
2. Butylated hydroxyanisole (BHA)
3. Butylated hydroxytoluene (BHT)
144
Naturally occuring antioxidants include Vitamin E (tocopherol), which is __________ and urate and Vitamin C which are _______.
Lipid soluble
Water soluble
145
Preventive antioxidants include catalase and other peroxidases such as ______________________ that react with ROOH.
Glutathione peroxidase
146
__________ which is an essential component of glutathione peroxidase and regulates its activity.
Selenium
147
DTPA
Diethylenetriaminepentaacetate
148
In vivo, the prinicipal-chain breaking antioxidants are _____________, which acts in the aqueous phase to trap superoxide free radicals urate and __________, which acts in the lipid phase to trap ROO radicals.
Superoxide dismutase
Vitamin E
149
Peroxidation is also catalyzed in vivo by heme compounds and by ______________ found in platelets and leukocytes.
Lipoxygenases
150
Other products of auto-oxidation or enzymic oxidation of physiologic significance include ______ (formed from cholesterol) and _______ (formed from the peroxodation of polyunsaturated fatty acids such as arachidonic acid).
Oxysterols
Isoprostanes
151
____________ may be formed by sonicating an ampiphatic lipid in an aqueous medium.
Liposomes
152
Aggregation of bile salts into micelles and liposomes and the formation of _____________ with the products of fat digestion are importamt in facilitating absorption of lipids from the intestine.
Mixed micelles
153
_____________ are of potential clinical use, particularly when combined with tissue-specific antibodies, as carriers of drugs in the circulation, targeted to specific organs for example in cancer therapy.
Liposomes
154
In addition, they are used for gene transfer into vesicular cells and as carriers for topical and transdermal delivery of drugs and cosmetics.
Liposomes
155
___________ are much larger particles, formed usually by nonpolar lipids in an aqueous medium.
Emulsions
