LIPIDS Flashcards
1
Q
are organic compounds
A
Lipids
2
Q
Chemical compounds in which one or more atoms of
carbon are covalently linked to atoms of other elements,
most commonly
A
hydrogen, oxygen, and nitrogen
3
Q
Several carbon atoms
attached to hydrogen
and oxygen
A
Carbohydrates
4
Q
s
■ Made up of amino
acids
■ Composition:
Carbon, Oxygen,
Hydrogen and
Nitrogen
■ Nitrogen is an atom unique to proteins
A
Proteins
5
Q
Several carbon
atoms are attached
to oxygen and
hydrogen
A
Lipids
6
Q
Also known as fats
Composed mostly of carbon-hydrogen (C-H) bonds
A
Lipid
7
Q
Rich source of energy
○ An efficient way of storing excess calories
■ Transported to the adipose cells
stored in the form of triglycerides
○ Play an integral part of the cell membrane of
the human cells
A
Lipid
8
Q
Refers to a collection of organic
molecules of varying chemical
composition
A
LIPIDS
9
Q
Are grouped together on the basis of
their solubility in nonpolar solvents
A
LIPIDS
10
Q
Lipids is composed of four main groups
A
fatty acids
glycerides
nonglyceride lipids
complex lipids
FGNC
11
Q
– When oxidized, each gram of fat releases 9 kcal of
energy, or more than twice the energy released by
oxidation of a gram of carbohydrate
A
Energy Source
12
Q
– In the form of triglycerides (TAG) in adipocytes
A
Energy Storage
13
Q
Phosphoglycerides, sphingolipids, and steroids
make up the basic structure of all cell membranes
A
Cell Membrane Structural Components
14
Q
make up the basic structure of all cell membranes
A
Phosphoglycerides, sphingolipids, and steroids
15
Q
Steroid Hormones
A
Hormones
16
Q
Lipid-soluble vitamins (A,D,E, and K)
A
Vitamins
17
Q
– Dietary fat serves as a carrier of the lipid-soluble
vitamins
A
Vitamin Absorption
18
Q
fats as shock absorber
A
Protection
19
Q
subcutaneous fat
A
Insulation
20
Q
Are long-chain
monocarboxylic
acids
A
FATTY ACIDS
21
Q
Generally contain an
even number of
carbon atoms
A
FATTY ACIDS
22
Q
Less than 6 carbons
A
- Short-Chain Fatty Acids
23
Q
6-10 carbons
A
Medium-Chain Fatty Acids
24
Q
More than 12 carbons
A
- Long-Chain Fatty Acids
25
– Each C being “saturated” with H
– General Formula: CH3(CH2)nCOOH
Saturated Fatty Acids
26
– Composed of at least one carbon-tocarbon double bond
– Almost are in the cis configuration
* Unsaturated Fatty Acids
27
– Composed of one carbon-to-carbon double
bond
Monounsaturated Fatty Acids (MUFA)
28
Composed of more than one carbon-tocarbon double bond
Polyunsaturated Fatty Acids (PUFA)
29
identified by position of the double
bond nearest the methyl end (CH3
) of the
carbon chain; this is described as an
omega number
30
are identified by position of the double
bond nearest the methyl end (CH3
) of the
carbon chain; this is described as an
omega number
Polyunsaturated Fatty Acids (PUFA)
31
If PUFA has first double bond 3 carbons
away from the methyl end =
omega 3 FA
32
6 carbons from methyl end =
omega 6 FA
33
H’s on same side of the double bond; fold
into a U-like formation; naturally occurring
cis-Fatty Acid
34
– H’s on the opposite side of the double
bond; occur in partially hydrogenated food
trans-Fatty Acid
35
– Fatty acids react with alcohols to form
esters and water
1. Esterification
36
– Producing fatty acids from esters
– Opposite of esterification
2. Acid Hydrolysis
37
Is the base-catalyzed hydrolysis of an
ester
3. Saponification
38
the product of this reaction, an ionized
salt, is a __________
Soap - Saponification
39
Have a long uncharged hydrocarbon tail and a
negatively charged terminus (the carboxylate
terminus), they form micelles that dissolve oil
and dirt particles
Saponification
40
Used in the food industry to convert
polyunsaturated vegetable oils into saturated
solid fats
4. Reaction at the Double Bond
(Unsaturated Fatty Acids)
Hydrogenation
41
* Carried out to add hydrogen to some, but not
all, double bonds in polyunsaturated oils
* In this way liquid vegetable oils are converted
into solid form (Crisco and margarine)
Partial Hydrogenation
42
Are lipid esters that contain the
glycerol molecule and fatty acids
Glycerides
43
Glycerides 2 Classes
Neutral Glycerides
Phosphoglycerides
44
nonionic and
nonpolar
Neutral Glycerides
45
have polar region,
the phosphoryl group, in addition to the
nonpolar fatty acid tails
Phosphoglycerides
46
most important and main
storage form of lipids in man (adipocytes
Triglycerides
47
– Produce after the esterification of glycerol
with a fatty acid
Neutral Glycerides
48
Esterification may occur at one, two, or all
three positions, producing:
Monoglycerides
* Diglycerides
* Triglycerides
49
– Are lipids that are not derived from glycerol
Sphingolipids
50
Amphipathic and structural components of
cellular membranes
Sphingolipids
51
Sphingolipids
Derived from _________(long chain, Ncontaining alcohol)
sphingosine
52
Located throughout the body, but are
particularly important structural lipid
components of nerve cell membranes
– Found in abundance in the myelin sheath
the surrounds and insulate cells of the CNS
Role is essential to proper cerebral
function and nerve transmission
* Sphingomyelins
53
– Are built on a _______ backbone structure,
which is a fatty acid amide derivative of
sphingosine
ceramide - Glycosphingolipids
54
– Include the cerebrosides, sulfatides, and
gangliosides
CSG
Glycosphingolipids
55
Are characterized by the presence of a
single monosaccharide head group
Cerebrosides
56
found in the membranes of
macrophages
Glucocerebroside
57
found almost exclusively
in the membranes of brain cells
Galactocerebroside
58
Consists of ceramide bonded to the hexose glucose
Glucocerebroside
59
Consists of ceramide joined to the monosaccharide
galactose
Galactocerebroside
60
– Contain the
steroid nucleus
(steroid carbon
skeleton)
Steroids
61
known sterol,
found in the
membranes
Cholesterol
62
– Amphipathic
– Involved in the regulation of the fluidity of
the membrane as a result of the nonpolar
fused ring
– Hydroxyl group is polar
Cholesterol
63
Cholesterol another name
– Perhydrocyclopentanophenanthrene ring
64
Can also exist in
an esterified form
called _________ with the
hydroxyl group
conjugated by an
ester bond to a
fatty acid
No polar
groups making
them very
hydrophobic
cholesteryl
ester - cholesterol
65
Almost exclusively synthesized by animals,
but plants do contain other sterols similar in
structure to cholesterol
* It is not readily catabolized by most cells,
therefore, does not serve as a source of
energy
* Can be converted in the liver to primary bile
acids (e.g. cholic acid) and chenodeoxycholic
acid
CHOLESTEROL
66
– Are amphipathic derivatives of cholesterol
– Synthesized in the liver and stored in the
gallbladder
Bile Salts
67
Steroid hormones
– Testosterone
– Progesterone
– Estrone, Estrogen, and its derivatives
– Cortisone and Cortisol
– Aldosterone
TEPCA
68
Derived from many different sources and
have a variety of chemical compositions,
depending on the source
Waxes
69
Example of waxes
Paraffin waxes
70
– protective coating for hair and skin
(used in skin creams and ointments)
Lanolin - Waxes
71
Are bonded to other types of molecules
Complex Lipids
72
Consist of a core of hydrophobic lipids
surrounded by amphipathic proteins,
phospholipids, and cholesterol
Lipoproteins
73
Typically spherical in
shape and range in size
10 to 1200 nm - lipoproteins
74
Composed of both
lipids and proteins,
called __________
apolipoproteins
75
Larger LPP particles have larger core
regions (contain relatively more TAG and
cholesteryl ester)
lipoproteins
76
The larger the LPP, the more lipid relative to
CHON, therefore, lighter in density
LIPOPROTEINS
77
Classification
(based on ultracentrifugation)
– Chylomicrons [chylos]
– Very-low-density LPP [VLDL]
– Low-density LPP [LDL]
– High-density LPP [HDL]
78
Location: surface of LPP particles
* Functions:
– Help maintain the structural integrity of LPP
– Serve as ligands for cell receptors
– Act as activators and inhibitors of the various
enzymes that modify LPP particles
* Contain “Amphipathic helix”
APOLIPOPROTEINS
79
– Major protein on HDL
– anti-atherogenic HDL present in plasma
Apo A-I
80
– Is a large protein with MW 500 kD
– Principal protein on LDL, VLDL, and
Chylomicrons
Apo B
81
Is found on LDL and VLDL
– Ligand for the LDL receptor
Apo B-100
82
Exclusively found in chylomicrons
Apo B-48
83
– Found in LDL, VLDL, and HDL
– Serves as a ligand for the LDL receptor and the chylomicron
remnant receptor
– Apo E2, Apo E3, Apo E4
Apo E
84
Contain apo B-48
* Account for the turbidity of postprandial
plasma
* Readily float to the top of stored plasma
and form a creamy layer
– chylous, turbid, milky, cloudy, lipemic
plasma/serum
* Produced by the intestine
* Deliver dietary (exogenous) lipids to
hepatic and peripheral cells
CHYLOMICRONS
85
Contain apo B-100, apo E, and apo C
* Produced by the liver
* Rich in TAG like chylomicrons
* Account for most of the turbidity observed in fasting hyperlipidemic
plasma specimens but do not form a top, creamy layer
* Major carriers of endogenous (hepatic derived) triglycerides
* Transfer TAG from the liver to peripheral tissue
VERY LOW DENSITY LIPOPROTEIN
86
Contains apo B-100 and apo E
* Primarily formed as a consequence of the lipolysis of
VLDL
* Readily taken up by cells via the LDL receptor
– Accounts for the reason that elevated LDL levels
promote atherosclerosis
* Significantly smaller than VLDL and chylomicrons
LOW DENSITY LIPOPROTEIN
87
Smallest and the most dense
* Synthesized by both the liver and intestine
* Can exist either as disk-shaped or as spherical-shaped particles
* DISCOIDAL HDL
– Most active form in removing excess cholesterol from peripheral cells
* SPHERICAL HDL
– HDL2
* Larger in size and richer in lipid than HDL3
* May be more efficient in delivering lipids to the liver
– HDL3
HIGH DENSITY LIPOPROTEIN
88
* Intermediate Density Lipoprotein
* Lipoprotein (a)
Minor:
89
* LpX Lipoprotein
* ẞ-VLDL Lipoprotein or Floating ẞ Lipoprotein
Abnormal
90
Formed through the metabolism of VLDL in
circulation; lipid content, size, and density of IDL is
intermediate between VLDL and LDL
Intermediate Density Lipoprotein
91
is similar to LDL in terms of density and overall
composition, and can be thought of as an LDL
particle to which apo(a) has been added, linked
to apoB-100 via a disulfide bond
Lipoprotein (a)
92
is an abnormal lipoprotein found in patients with
obstructive biliary disease, and in patients with
familial lecithin/cholesterol acyltransferase (LCAT)
deficiency
LpX Lipoprotein
93
is an abnormal lipoprotein that accumulates in type
3 hyperlipoproteinemia
ẞ-VLDL Lipoprotein / Floating ẞ Lipoprotein
94
most active form in removing excess cholesterol from peripheral cells
Discoidal HDL
95
Larger in size and richer in lipid than HDL3
May be more effecient in delivering lipids to liver
HDL2
