BIOCHEM LIPIDS Flashcards
1
Q
are a heterogeneous group of compounds, including fats, oils, steroids, waxes, and related compounds
A
LIPIDS
2
Q
LIPIDS soluble in ___________ solvents such as _______ and ___________
A
nonpolar, ether, chloroform
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 ω3 fatty acids
4
Q
Fat is stored in ___________
A
adipose tissue
5
Q
Lipids are transported in the blood combined with proteins in _____________ particles
A
lipoprotein
6
Q
include fats, oils, and waxes which are esters of fatty acids with various alcohols
A
Simple lipids
7
Q
Esters of fatty acids with glycerol
A
Fats
8
Q
Fats in the liquid state at room temperature
A
Oils
9
Q
Esters of fatty acids with higher molecular weight
monohydric alcohols
A
Waxes
10
Q
are esters of fatty acids, which always contain an alcohol and one or more fatty acids, but which also
have other groups
A
Complex lipids
11
Q
Contain a phosphoric acid residue.
They frequently have nitrogen-containing bases (eg,
choline) and other substituents
A
Phospholipids
12
Q
Contain a fatty acid,
sphingosine, and carbohydrate.
A
Glycolipids
13
Q
derivatives of C-20 fatty acids
A
EICOSANOIDS
14
Q
In many phospholipids
the alcohol is glycerol (_____________________), but in
________________ it is sphingosine, which contains an amino group.
A
glycerophospholipids, sphingophospholipids
15
Q
are formed from the hydrolysis of both simple and complex lipids
A
Derived Lipids
16
Q
include bile salts, steroids, hormones, ketone bodies, lipid-soluble vitamins and polyprenoids
A
Derived Lipids
17
Q
Fatty acids occur in the body mainly as _________________, but are found in the unesterified form as ________________, a transport form in the plasma.
A
esters in natural fats and oils, free fatty acids
18
Q
__________ fatty acids end in –anoic
A
Saturated
19
Q
______________ fatty acids with double bonds end in -enoic
A
unsaturated
20
Q
►Carbon atoms are numbered starting from the _____________ (C1)
►carbon adjacent to carboxyl carbon (C2, C3,and C4) 🡪 ________________________________respectively
►terminal methyl carbon is known as ______________
A
carboxyl carbon, (alpha, beta and gamma carbons), omega carbon
21
Q
Use _______ for indicating the number and position of the double bonds
A
delta
22
Q
SATURATED FATTY ACIDS
►Based on the CH3COOH or ____________ as the
first member of the series
►______ is progressively added between the terminal CH3 & the COOH groups
A
Acetic Acid, CH2
23
Q
►carbons of saturated fatty acids form a _________ pattern at low temperature
►at higher temperature some bonds_________ causing shortening of the chain
A
Zigzag, Rotate
24
Q
Number of C atoms in Acetic
A
2
25
Number of C atoms in Butyric
4
26
Number of C atoms in Valeric
5
27
Number of C atoms in Caproic
6
28
Number of C atoms in Lauric, Myristic, Palmitic, Stearic
12, 14, 16, 18
29
acids, containing one double bond
Monounsaturated
30
acids, containing two or more double bonds
Polyunsaturated
31
These compounds, derived from eicosa (20-carbon) polyenoic fatty acids
EICOSANOIDS
32
_____________________ occurs in
unsaturated fatty acids because of the double bond
Geometric Isomerism
33
comprise the prostanoids, leukotrienes (LTs), and lipoxins
(LXs)
Eicosanoids
34
exist in virtually every mammalian tissue, acting as local hormones; they have important physiologic
and pharmacologic activities.
Prostaglandins
35
compounds that have the cyclopentane ring interrupted with an oxygen atom
thromboxane
36
are a third group
of eicosanoid derivatives formed via the lipoxygenase pathway
(see Figure 23–13). They are characterized by the presence of
three or four conjugated double bonds, respectively
The leukotrienes and lipoxins
37
Leukotrienes cause bronchoconstriction as well as being potent proinflammatory agents, and play a part in ___________
asthma
38
Double bonds in naturally occurring unsaturated long-chain fatty acids are nearly all in the cis configuration, the molecules being “bent” ________ at the double bond
120°
39
NON-ESSENTIAL FATTY ACIDS
►Synthesized from products of _______ oxidation
►Non-essential in the sense that they do not necessarily be included in the diet
glucose
40
ESSENTIAL FATTY ACIDS
►__________ and __________ Acids
►Must be obtained from the diet
►No human enzyme system can
introduce a double bond beyond the ______ carbon atom of fatty acid
Linoleic, Linolenic, ninth
41
►Corn Oil, Peanut Oil, Cottonseed Oil and Soybeans
Linoleic Acid
42
►Linseed Oil and Evening Primrose Oil
Linolenic Acid
43
Detergent-like due to ____________________, have nonpolar (CH3) & polar (-COOH) ends
amphipathic nature
44
OMEGA 3 FATTY ACIDS
►_______________ in plant oils, __________________ in fish oils and ____________________ in fish & algal oils
►anti-inflammatory effects
►stimulatory effect in synthesis of less inflammatory prostaglandins & leukotrienes
►Potential use as therapy for chronic inflammatory disease
Alpha-linolenic (ALA), Ecosapentaenoic acid (EPA), Docosahexanenoic acid (DHA)
45
►Main storage form of fatty acids
TRIACYLGLYCEROLS
46
Give rise to G1 Prostanoids and G3 Luekotrienes
Linoleic Acid
47
give rise to Group 2 Prostanoids, Group 4 Leukotrienes and Lipoxins
Arachidonic Acid
48
____________ give rise to
Eicosapentaenoic Acid (EPA)
Linoleic Acid
49
►give rise to Group 3 Prostanoids
and Group 5 Leukotrienes
Eicosapentaenoic Acid (EPA)
50
PHOSPHOLIPIDS are derivatives of __________________
Phosphatidic acid
51
________________________ containing choline are the most abundant phospholipids of the cell membrane and represent a large proportion of the body’s store of choline
Glycerophospholipids
52
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
53
also plays a role in apoptosis(programmed cell death).
Phosphatidylserine
54
►found in most tissues; cell membranes
►ethanolamine and serine replaces choline in phosphatidylcholine
(Cephalin) and Phosphatidylserine
55
_______________ 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
56
found only in the mitochondria; essential for mitochondrial function
Cardiolipin
57
►Found in oxidized lipoproteins and implicated in some of their effects in promoting atherosclerosis
Lysophosphatidylcholine
(Lysolecithin)
58
►Constitute much as 10 -30 % of
phospholipids in brain and heart
Plasmalogens
59
►Contain no glycerol, and on hydrolysis yield fatty acid, phosphoric acid, choline and sphingosine
Sphingomyelins
60
►The combination of fatty acid plus sphingosine is known as ______________ a structure also found in glycosphingolipids
ceramide
61
principal sialic acid found in human tissue also present in the nervous tissue in high
concentration
►Neuraminic Acid
62
►cell-cell recognition and cell communication
►receptors for hormones and bacterial
toxins, such as cholera toxin
Gangliosides
63
►Often found as cholesterol ester,
where -OH group on sn-3 is
esterified with long chain fatty acid
►CHOLESTEROL
64
►Derived from cholesterol by
scission of 3 carbon side chain
►BILE ACIDS:
65
►Formed in liver from cholesterol
►PRIMARY BILE ACIDS
66
►PRIMARY BILE ACIDS
►CHOLIC ACID
►CHENODEOXYCHOLIC
ACID
67
Formed in intestine from primary bile acids through the
action of intestinal bacterial enzymes
►SECONDARY BILE ACIDS
68
►SECONDARY BILE ACIDS
►DEOXYCHOLIC ACID
►LITHOCHOLIC ACID
69
Synthesized from cholic acid
► Hydroxyl groups at carbons 3 and 12
►DEOXYCHOLIC ACID
70
non-absorbable bile acids
► Synthesized from chenodeoxycholic acids
► OH group at carbon 3
► About 400 mg/day is excreted in feces daily
►LITHOCHOLIC ACID
71
common precursor of STEROID HORMONES:
►Cholesterol,
72
Hormones of the Adrenal Cortex:
Cortisol produced by ________________________
zona fasciculata
73
►complexes of protein and lipids with noncovalent bonds
LIPOPROTEINS
74
LIPOPROTEINS
► ______________ segment
directed inward
► ___________ face
the water outside
nonpolar, polar segments
75
►Transport triacylglycerol from the liver to the tissues
►VERY-LOW DENSITY LIPOPROTEIN
(VLDL)
76
________________________ of lipids exposed to oxygen forming peroxides 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)
77
►initial products of VLDL degradation
►INTERMEDIATE DENSITY
LIPOPROTEIN (IDL)
78
►LOW DENSITY LIPOPROTEIN (LDL)
Bad Fat
79
►HIGH DENSITY LIPOPROTEIN (HDL)
Good Fat
80
►not steroid, but are related because they are
synthesized from five carbon isoprene units,
like cholesterol
POLYPRENOIDS
81
*widely distributed in all cells of the body, particularly in CNS
CHOLESTEROL
82
carries cholesterol & cholesteryl ester to many tissues
◦LDL (low density lipoprotein)
83
◦removes free cholesterol from tissues & transports
them to the liver
◦HDL (high density lipoprotein)
84
A major component of gallstones
CHOLESTEROL
85
________________ is both an end point of fatty acid catabolism an the starting substrate for fatty acid synthesis
acetyl-CoA
86
In plasma, longer-chain FFA are combined with ______________, and in cell they are attached to a fatty acid–binding protein
albumin
87
Amount Product Formed (mol)/mol Palmitate for β-Oxidation FADH2
7
88
Amount Product Formed (mol)/mol Palmitate for β-Oxidation NADH
7
89
Fatty acid oxidation in mitochondria leads to the generation of large quantities of ATP by a process called_____________ that cleaves acetyl-CoA units sequentially from fatty acyl chains. The acetyl-CoA is oxidized in the citric acid cyce, generating further ATP
β-oxidation
90
Fatty acids are synthesized by an _____________________, which is responsible for the complete synthesis of palmitate
from acetyl-CoA in the ________________
extramitochondrial system, cytosol
91
In most mammals, _________
is the primary substrate for lipogenesis, but in ruminants it
is ___________, the main fuel molecule they obtain from the diet.
glucose, acetate
92
The initial step in fatty acid synthesis is the carboxylation of
acetyl-CoA to form malonyl-CoA by acetyl-CoA carboxylase. The reaction requires _______ and the _______________
B vitamin biotin
93
converts surplus glucose and intermediates such
as pyruvate, lactate, and acetyl-CoA to fat, assisting the anabolic
phase of this feeding cycle.
Lipogenesis
94
stimulates lipogenesis by several other mechanisms as well as by increasing acetyl-CoA carboxylase activity
Insulin
95
are the only fatty acids known to be essential for the complete nutrition of many species of animals, including humans, and are termed the nutritionally essential fatty acids
Linoleic and α-linolenic acids
96
____________ plays an important role, promoting gene expression and induction of enzyme biosynthesis, and ______ (via cAMP) antagonizes this effect
Insulin, glucagon
97
_____________________ in the cell membrane act as precursors of hormone second messengers, and platelet activating factor (PAF),
Inositol phospholipids
98
Important substances
such as triacylglycerols, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and cardiolipin, a constituent
of mitochondrial membranes, are formed from ___________________________
glycerol 3 -phosphate.
99
____________________________ are found predominantly in the 1 position of phospholipids, whereas the ______________________________ (eg, the precursors of prostaglandins)are incorporated more frequently into the 2 position.
Long-chain saturated fatty acids , polyunsaturated fatty acids
100
is synthesized in the endoplasmic reticulum from the amino acid serine as shown in
Ceramide
101
is composed mainly of lipid with some proteins and carbohydrate and prevents the alveoli from collapsing
Lung surfactant
102
Enzyme Deficiency of Tay-Sachs disease
Hexosaminidase A, S
103
Enzyme Deficiency of Fabry disease
α-Galactosidase
104
Enzyme Deficiency of Metachromatic
leukodystrophy
Arylsulfatase A
105
Enzyme Deficiency of Krabbe disease
β-Galactosidase
106
Enzyme Deficiency of Krabbe disease
β-Galactosidase
107
Enzyme Deficiency of Gaucher disease
β-Glucosidase
108
Enzyme Deficiency of Niemann-Pick
disease types A, B
Sphingomyelinase
109
Enzyme Deficiency of Farber disease
Ceramidase
110
Insulin deficiency causes excess mobilization
of FFAs + underusage of chylomicrons and VLDL →
hyper triacylglycerolemia
HYPERLIPOPROTEINEMIAS
111
CLASSES OF PLASMA LIPIDS
Cholesterol (14%)
Triacylglycerols (16%)
Phospholipids (30%)
Cholesteryl esters (36%)
Free fatty acids, FFAs (4%) → metabolically,
the most active of the plasma lipids
112
Most active among plasma lipids
FREE FATTY ACIDS
113
derived from intestinal absorption of t triacylglycerol (TAG) & other lipids
Chylomicrons
114
derived from liver for the export of TAG
Very Low Density Lipoproteins (VLDL)
115
represents final stage of VLDL catabolism
Low Density Lipoproteins (LDL)
116
involved in cholesterol transport + VLDL and chylomicron metabolism
High Density Lipoproteins
117
Classification according to
electrophoretic properties
Alpha – (HDL)
Beta – (LDL)
Pre beta – (VLDL)
118
Structure of Lipoproteins
- Nonpolar core =
________________________________
- Outer Layer = _______________________
triacylglycerol + cholesteryl
ester, phospholipid +
cholesterol
119
`proteins that bind lipids to form lipoproteins
APOLIPOPROTEINS
120
proteins that bind lipids to form lipoproteins
One or more may be present in each
lipoprotein
APOLIPOPROTEINS (apoprotein)
121
Thought to have a role in chylomicron metabolism
May act as a regulator of satiety & glucose
homeostasis → potential therapeutic target for
treatment of diabetes and obesity
Apo A-IV
122
important factor in human neurodegenerative
disease
Apo D
123
Major apoproteins of HDL
apo A
124
Main apoproteins of LDL
apo B (B-100)
125
form LDL (“bad cholesterol”),
have beta sheet structure, stick to lipids irreversibly
Apolipoprotein B
126
form HDL (“good
cholesterol”), have alpha helix structures, stick to
lipids reversibly
apo A & other apolipoproteins
127
Normal apoB100 levels → ____________________
40-125 mg/dL
128
Found in chyle (formed by lymphatic system
draining the intestine)
Responsible for transport of all dietary lipids
into the circulation
transports triacylglycerol from liver to the
extrahepatic tissues
CHYLOMICRONS
129
Apo ___ is essential for chylomicron & VLDL
formation
B
130
Chylomicrons are cleared from the blood → half of them
disappear in < __ hour
1
131
Where do fatty acids from chylomicron triacylglycerol go?
____ to adipose, heart & muscle
____ to liver
80%, 20%
132
The LDL receptor is specific for apo ________ but not apo B-48
B-100
133
___ of LDL is degraded in extrahepatic
tissues; ____ degraded in liver
30%, 70%
134
needed for
the formation of the TAG-rich
particles and/or VLDL2
Phosphatidic acid
135
accumulation of lipid, mainly TAG
Fatty liver
136
Most common liver disorder worldwide
nonalcoholic
fatty liver
137
Oxidation of ethanol by alcohol dehydrogenase →
excess production of NADH → increased
esterification of fatty acids to form TAG → fatty liver
Alcoholic Fatty Liver
138
Made from acyl-CoA +
glycerol-3-phosphate
Triacylglycerol (TAG)
139
Used for thermogeneration
Where seen?
Animals waking up from hibernation
Animals exposed to cold (non-shivering thermogenesis)
Heat production in newborn
BROWN ADIPOSE TISSUE
140
protein involved in formation of lipid droplets in adipocytes
Enables storage and breakdown of TAG as needed by the
body
Perilipin
141
______________________ sympathetic nerve endings is important in
increasing lipolysis in tissues
Increasing synthesis of lipoprotein lipase to enhance
use of TAG-rich lipoproteins from the circulation
Norepinephrine
