Lipids of Physiologic Significance Flashcards
PROPERTIES OF LIPIDS
relatively insoluble in water and
soluble in
nonpolar solvents
WHICH OF THE FOLLOWING IS CORRECT?
A. Lipids are important
dietary constituents not only because of the high energy value of fats
B. essential fatty acids, fat-soluble vitamins, and other
lipophilic micronutrients are contained in the fat of natural foods
C. Dietary
supplementation with long-chain ω3 fatty acids is believed to have
beneficial effects in a number of chronic diseases, including cardiovascular
disease, rheumatoid arthritis, and dementia.
D. All of the above
D. All of the above
Fat is stored in
adipose tissue
are esters of fatty acids
with various alcohols:
Simple lipids
Which statement is incorrect?
A. Fat is stored in connective tissue,
where it also serves as a thermal insulator in the subcutaneous tissues and
around certain organs.
B. Nonpolar lipids act as electrical insulators,
allowing rapid propagation of depolarization waves along myelinated
nerves.
C. Lipids are transported in the blood combined with proteins in
lipoprotein particles
D. None of the above
A. Fat is stored in adipose tissue
Fats
Esters of fatty acids with glycerol.
Fats in the liquid
state.
Oils
Waxes
Esters of fatty acids with higher molecular weight
monohydric alcohols.
esters of fatty acids, which always contain an alcohol and one or more fatty acids, but which also have other groups.
Complex lipids
Contain a phosphoric acid residue. They frequently have nitrogen-containing bases (eg, choline) and other substituents.
Phospholipids:
Which is incorrect?
A. Phospholipids frequently
have nitrogen-containing bases (eg, choline) and other substituents.
B. Glycerophospholipids are type of phospholipid is which the alcohol is glycerol
C. Sphingophospholipids are type of phospholipid is which the alcohol is spinghosine, which contains a carbohydrate group
D. Glycolipids (glycosphingolipids) are fatty acid
sphingosine, and carbohydrate.
C. Sphingophospholipids are type of phospholipid is which the alcohol is spinghosine, which contains a carbohydrate group
sphingophospholipids it is
sphingosine, which contains an amino group.
Example of other complex lipids except: A. Lipoproteins B. Sulfolipids C. Waxes D. amino lipids
C. Waxes
formed from the hydrolysis of both simple and complex lipids.
Derived lipids
Which is untrue?
A. Derived lipids are formed from the hydrolysis of both simple and
complex lipids
B. They include fatty acids, glycerol, steroids, other
alcohols, fatty aldehydes, ketone bodies,
hydrocarbons, lipid-soluble vitamins and micronutrients, and
hormones.
C. Some of these (eg, free fatty acids, glycerol) also act as
precursor lipids in the formation of simple and complex lipids.
D. Because they are uncharged, acylglycerols (glycerides), cholesterol, and
cholesteryl esters are termed neutral lipids.
E. None of the above
E. None of the above
Which is correct?
A. Fatty acids occur in the body mainly as esters in natural fats and oils, but are found in the esterified form as free fatty acids, a transport form in
the plasma
B. Fatty acids that occur in natural fats usually contain an odd
number of carbon atoms.
C. Fatty acids are aliphatic carboxylic acids
D. The head may be saturated (containing no double bonds) or unsaturated (containing one or more double bonds)
C. Fatty acids are aliphatic carboxylic acids
The naming system in which systematic nomenclature names the fatty acid
after the hydrocarbon with the same number and arrangement of carbon
atoms, with -oic being substituted for the final -e
Genevan system
end in -anoic
saturated acids
for example, octanoic acid (C8),
end in -enoic
unsaturated acids with double bonds octadecenoic acid (oleic acid, C18).
Which is true?
A. Carbon atoms are numbered from the carboxyl carbon (carbon no. 1).
B. The carbon atoms adjacent to the carboxyl carbon (nos. 2, 3, and 4) are
also known as the α, β, and γ carbons, respectively, and the terminal
methyl carbon is known as the ω- or n-carbon.
C. All of the above
D. None of the above
C. All of the above
Which statement is incorrect?
A. Δ9 indicates a double bond
between carbons 9 and 10 of the fatty acid
B. ω9 indicates a double bond on
the ninth carbon counting from the ω-carbon
C. In plants, additional double
bonds can be introduced only between an existing double bond at the ω9, ω6, or ω3 position and the carboxyl carbon, leading to three series of fatty
acids known as the ω9, ω6, and ω3 families,
D. None of the above
C. In animals, additional double
bonds can be introduced only between an existing double bond at the ω9, ω6, or ω3 position and the carboxyl carbon, leading to three series of fatty
acids known as the ω9, ω6, and ω3 families,
Which is incorrect?
A. Saturated Fatty Acids Contain No Double Bonds
B. Unsaturated Fatty Acids Contain One or More Double Bonds
C. All of the above
D. None of the above
D. None of the above
What fatty acid contains 4 C atoms that can be find in certain fats in small amounts (especially butter). It is an end product of carbohydrate fermentation by rumen organism
Butyric
How many carbon atom is Acetic acid?
2
How many carbon atom in Valeric acid?
5
6 carbon fatty acid
Caproic acid?
How many carbon atom in Lauric acid?
12
Can be found in spermaceti, cinnamon, palm kernel, coconut oils, laurel, butter
Lauric Acid
14 carbon fatty acid
can be found in nutmeg, palm kernel, coconut oils, butter
myristic
16 carbon fatty acid
Palmitic
How many carbon is Stearic Acid
18
All are one double bond unsaturated fatty acid except? A. Palmitoleic B. Oleic C. Elaidic D. Linoleic
D. Linoleic
Systemic name for Elaidic Acid which is a C18 with double bond on 1;9 carbon atoms
trans-9-octadecenoic
Under w7 family of fatty acid that can be found in nearly all fats
Palmitoleic
All are under w3 family except: A. Cervonic B. Timnodonic C. a-Linolenic D. y-Linolenic
D. y-Linolenic
All are under w9 except A. Oleic B. Elaidic C. None of the above D. All of the above
C. None of the above
containing one double bond
Monounsaturated
Polyunsaturated
containing two or
more double bonds.
derived from eicosa (20-carbon)
polyenoic fatty acids
Eicosanoids
Eicosanoids comprises of all except: A. Prostanoids B. Leukotrienes C. Lipoxins D. None of the above
D. None of the above
Prostanoids is/are: A. Prostglandins B. Prostacyclins C. Thromboxanes D. All of the above
D. All of the above
exist in virtually every mammalian tissue, acting as local hormones; they have important physiologic and pharmacologic
activities.
Prostaglandins
Which statement is incorrect?
A. Prostaglandins are synthesized in vivo by cyclization of the center of the carbon chain of 20-carbon (eicosanoic) polyunsaturated fatty acids (eg, arachidonic acid) to form a cyclopentane ring
B. A related series of compounds, the thromboxanes, have the cyclopentane ring interrupted with an oxygen atom (oxane ring)
C. Three different eicosanoic fatty acids give rise to three groups of eicosanoids
characterized by the number of double bonds in the side chains
D. Different substituent groups attached to the rings give rise to series of prostaglandins and thromboxanes labeled 1, 2, etc
D. Different substituent groups attached to the rings give rise to series of prostaglandins and thromboxanes labeled 1, 2, etc
should be
Different substituent groups attached to the rings give rise to series of prostaglandins and thromboxanes labeled A, B, etc
Which statement is correct?
A. the “F” type of prostaglandin has a keto group in position 9
B. the “F” type has a hydroxyl group in position 9
C. The leukotrienes and lipoxins are a third group of eicosanoid
derivatives formed via the cyclooxygenase pathway
D. Thromboxanes cause bronchoconstriction as well as being potent proinflammatory agents, and play a part in asthma.
B. the “F” type has a hydroxyl group in position 9
Which is/are true?
A. The carbon chains of saturated fatty acids form a zigzag pattern when
extended at low temperatures
B. A type of geometric
isomerism occurs in unsaturated fatty acids, depending on the orientation
of atoms or groups around the axes of double bonds, which do not allow
rotation
C. At higher temperatures, some
bonds rotate, causing chain shortening, which explains why biomembranes
become thinner with increases in temperature
D. All of the above
E. None of the above
D. All of the above
Which is correct?
A. If the acyl chains are on the same side of the bond, it is trans-,
B. if on opposite sides, it is trans-,
C. Double bonds in naturally occurring
unsaturated long-chain fatty acids are nearly all in the trans configuration,
the molecules being “bent” 120° at the double bond.
D. elaidic acid, is a cis isomer
B. if on opposite sides, it is trans-
present 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
Which is true:
A. Consumption of trans fatty acids is not known to be detrimental to health
and is associated with increased risk of diseases including cardiovascular
disease and diabetes mellitus.
B. The melting points of even-numbered carbon fatty acids increase with
chain length and decrease according to unsaturation.
C. A triacylglycerol containing three saturated fatty acids of 12 or more carbons is liquid at body temperature
D. if the fatty acid residues are saturated, it is liquid to below 0°C
B. The melting points of even-numbered carbon fatty acids increase with
chain length and decrease according to unsaturation.
Which statement is incorrect?
A. Long-chain ω3 fatty acids such as α-linolenic (ALA) (found in plant oils),
eicosapentaenoic (EPA) (found in fish oil), and docosahexaenoic (DHA) (found in fish and algal oils) have anti-inflammatory effects
B. diets rich in ω3 fatty acids
are beneficial, particularly for cardiovascular disease, but also for other
chronic degenerative diseases such as cancer, rheumatoid arthritis, and
Alzheimer disease.
C. All of the above
D. None of the above
D. None of the above
esters of the trihydric alcohol
glycerol and fatty acids
triacylglycerols
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
(glycerophospholipids)
phosphatidic acid
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
______ such
as sphingomyelin, in which the phosphate is esterified to sphingosine, a complex amino alcohol , are also important membrane components
Sphingolipids
Which statement is not true:
A. Both glycerophospholipids and sphingolipids have two longchain hydrocarbon tails which are important for their function in forming the lipid bilayer in cell membranes
B. Both tail of glycerophospholipid are fatty acid chains
C. For spingolipids one is a fatty acid and the second is
part of the sphingosine molecule
D. All of the above
E. None of the above
E. None of the above
important in nervous transmission, as
acetylcholine, and as a store of labile methyl groups
Choline
This is glycerophospholipids containing choline , are the most abundant phospholipids of the cell membrane and represent a large proportion of the
body’s store of choline
(phosphatidylcholines, commonly called lecithins)
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
absence of Dipalmitoyl lecithin from the lungs of premature infants causes
respiratory distress syndrome.
True or false:
Most phospholipids have a saturated acyl radical in the sn-1 position but an unsaturated radical in the
sn-2 position of glycerol.
True
plays a role in apoptosis (programmed cell death).
Phosphatidylserine
minor components of cell membranes, but play an
important part in cell signaling and membrane trafficking.
Phosphorylated phosphatidylinositols
phosphoinositides
cleaved into diacylglycerol and inositol trisphosphate upon stimulation by a suitable hormone agonist, and both of these act as internal signals or second messengers.
Phosphatidylinositol 4,5-bisphosphate (PiP2)
Is a Major Lipid of Mitochondrial
Membranes
Cardiolipin
Phosphatidic acid is a precursor of phosphatidylglycerol, which in turn
gives rise to _________
cardiolipin
This phospholipid is found only in
mitochondria and is essential for the mitochondrial function
cardiolipin
These diseases happen when decreased
cardiolipin levels or alterations in its structure or metabolism happens, except:
A. mitochondrial dysfunction in aging B. heart failure, C. hypothyroidism D. Barth syndrome (cardioskeletal myopathy). E. All of the above F. None of the above.
F. None of the above.
These are phosphoacylglycerols containing only one acyl radical, which is important in the metabolism and interconversion of phospholipids
Lysophospholipids
This compound is also found in oxidized lipoproteins and has been implicated in some of their effects in promoting atherosclerosis.
Lysophospholipids
These compounds constitute as much as 10 to 30% of the phospholipids of brain and heart.
Plasmalogens
resemble phosphatidylethanolamine but possess an ether link on the sn-1 carbon instead of the ester link found in acylglycerols.
Plasmalogens
True of plasmalogens:
A. Typically, the alkyl radical is an unsaturated alcohol
B. choline, serine, or inositol may be substituted for ethanolamine.
C. The function of plasmalogens remain poorly understood, but it has been suggested that
they may have a protective effect against reactive oxygen species.
D. All of the above
E. None of the above
D. All of the above
major glycolipids found in animal tissues are
glycosphingolipids
They contain ceramide and one or more sugars
glycosphingolipids
is a major glycosphingolipid of brain and other nervous
tissue, found in relatively low amounts elsewhere.
It contains a number of characteristic C24 fatty acids, for example, cerebronic acid.
Galactosylceramide
Galactosylceramide can be converted to sulfogalactosylceramide (sulfatide) which has a sulfo group attached to the O in the three position
of galactose and is present in high amounts in _____
myelin
resembles galactosylceramide, but the head group is glucose rather than galactose
Glucosylceramide
the predominant simple glycosphingolipid of extraneural tissues
Glucosylceramide
are complex glycosphingolipids derived from glucosylceramide that contain in
addition one or more molecules of a sialic acid
Gangliosides
is the principal sialic acid found in human tissues.
Neuraminic acid (NeuAc )
They function in cell–cell recognition and communication
and as receptors for hormones and bacterial toxins such as cholera toxin.
Gangliosides
The simplest ganglioside found in tissues is _________ which contains ceramide, one molecule of glucose, one molecule of galactose, and one molecule of NeuAc.
GM3
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
What does G M and the subscript means?
G represents
ganglioside
M is a monosialo-containing species;
and the subscript 3 is a
number assigned on the basis of chromatographic migration
It is the precursor of a large number of equally important steroids that include the bile acids, adrenocortical hormones, sex hormones, vitamin D, and cardiac glycosides
cholesterol
All steroids have a similar cyclic nucleus resembling phenanthrene (rings A, B, and C) to which a ____________ is attached
cyclopentane ring (D)
Which of the following is not true:
A. Each of the six-carbon rings of the steroid nucleus is capable of existing in the three-dimensional conformation either of a “chair” or a “boat”
B. In naturally occurring steroids, virtually all the rings are in the “chair” form, which is the more stable conformation.
C. the rings can only be cis
D. The methyl groups attached to C10
and C13 are invariably in the β configuration.
E. All of the above
F. None of the above
C
With respect to each other, the rings can be either cis or trans
Which is true?
A. The junction between the A and B rings may be cis or trans in naturally occurring steroids.
B. The junction between B and C is trans, as is usually the C/D junction.
C. The A ring of a 5α steroid (ie, the hydrogen at position 5 is in the α configuration) is always
trans to the B ring, whereas it is cis in a 5β steroid (ie, the hydrogen at position 5 is in the β configuration).
D. The methyl groups attached to C10 and C13 are invariably in the β configuration.
E. All of the above
F. None of the above
E. All of the above
is widely distributed in all cells of the body
but particularly in nervous tissue. It is a major constituent of the plasma membrane and of plasma lipoproteins
Cholesterol
It is often found as ______________ where the hydroxyl group on position 3 is esterified with a long-chain fatty acid. It occurs in animals but not in
plants or bacteria.
cholesteryl ester
Is a Precursor of Vitamin D
Ergosterol
occurs in plants and yeast and is important as a dietary source of vitamin D
Ergosterol
Which is correct?
A. When irradiated with ultraviolet light in the
skin, ring A is opened to form vitamin D2
B. When irradiated with ultraviolet light in the
skin, ring B is opened to form vitamin D2
C. When irradiated with ultraviolet light in the
skin, ring C is opened to form vitamin D2
D. All of the above
E. None of the aboe
B
When irradiated with ultraviolet light in the
skin, ring B is opened to form vitamin D2 in a process similar to the one
that forms vitamin D3 from 7-dehydrocholesterol in the skin
are not steroids but are related to them because they are synthesized, like cholesterol from five-carbon isoprene units
Polyprenoids
The process in which exposed to oxygen is responsible not only for deterioration of foods (rancidity), but also for damage to tissues in vivo, where it may be a cause of cancer, inflammatory diseases, atherosclerosis, and aging.
Peroxidation (auto-oxidation) of lipids
molecules that have unpaired valence electrons,
making them highly reactive.
free radicals
Free radicals containing oxygen (eg, ROO•,
RO•, OH•) are termed
reactive oxygen species (ROS).
produced during peroxide formation from fatty acids containing
methylene-interrupted double bonds, that is, those found in the naturally
occurring polyunsaturated fatty acids
reactive oxygen species (ROS).
is a chain reaction in which free radicals formed in the initiation stage in turn generate more (propagation), and thus it has potentially devastating
effects.
Lipid peroxidation
only formed by fatty acids with three or more double bonds and is used as a measure of lipid peroxidation together with ethane from the terminal two carbons of ω3 fatty acids and pentane from the terminal five carbons of ω6 fatty acids.
Malondialdehyde
correct sequence of lipid peroxidation:
initiation, propagation, termination
are used to control and reduce lipid peroxidation, both by humans in their activities and in nature.
Antioxidants
All are antioxidant except:
A. Propyl gallate B. butylated hydroxyanisole (BHA) C. butylated hydroxytoluene (BHT) D. Tocopherol E. All of the above F. None of the above
F. None of the above
True of antioxidant except:
A. vitamin E (tocopherol) is lipid soluble,
B. vitamin E (tocopherol) is water soluble soluble,
C. vitamin C is water soluble
D. urate is water soluble
E. All of the above
F. None of the above
B.
because:
vitamin E (tocopherol) is lipid soluble,
Antioxidants fall into two classes:
preventive and chain-breaking antioxidants,
which reduce the rate of chain initiation
preventive
antioxidants
interfere with chain propagation
chain-breaking antioxidants,
True of Preventive antioxidants:
A. include catalase
B. glutathione peroxidase that react with ROOH
C. In vivo, the principal chain-breaking antioxidants are superoxide dismutase, which acts in the aqueous phase to trap superoxide free radicals
D. All of the above
E. None of the above
D. All of the above
True of peroxidation:
A. Peroxidation is also catalyzed in vivo by heme compounds and by lipoxygenases found in platelets and leukocytes.
B. Other products of auto-oxidation or enzymic oxidation of physiologic significance include oxysterols (formed from cholesterol) and the prostaglandin-like isoprostanes (formed from the peroxidation of
polyunsaturated fatty acids such as arachidonic acid) which are used as reliable markers of oxidative stress in humans.
C. All of the above
D. None of the above
C. All of the above
are used as reliable markers of oxidative stress in humans.
isoprostanes (formed from the peroxidation of
polyunsaturated fatty acids such as arachidonic acid)
True of lipids:
A. lipids are insoluble in water since they contain a predominance of nonpolar (hydrocarbon) groups
B. fatty acids, phospholipids, sphingolipids, bile salts, and, to a lesser extent, cholesterol contain polar
groups.
C. a part of the molecule is hydrophobic, or water
insoluble, and a part is hydrophilic, or water soluble. Such molecules are described as amphipathic
D. A bilayer of such amphipathic lipids is the basic
structure in biologic membranes
E. All of the above
F. None of the above
E. All of the above
When a critical concentration of these lipids is present in an aqueous medium, they form
micelles
may be formed by sonicating an amphipathic lipid in
an aqueous medium.
Liposomes
are much larger particles, formed usually by nonpolar lipids in an aqueous medium.
Emulsions
