LIPIDS AND LIPOPROTEINS Flashcards
(129 cards)
1
Q
Essential in energy metabolism of the body
Clinically important in the diagnosis of coronary heart disease
A
LIPIDS AND LIPOPROTEINS
2
Q
Included in: Cardiac Profile Test
A
TC
TG
HDL C
LDL C
3
Q
marker for cardiac
diseases
A
CKMB
4
Q
3 normal isoenzymes:
A
MB MM BB
5
Q
Troponin has 3 forms:
A
troponin I,C,T
6
Q
SGOT OR AST
A
serum glutamic oxaloaacetic transaminase
aspartate aminotransaminase
7
Q
commonly known as fats
Rich source of energy and efficient way to store
excess calories: C-H bond
A
lipids
8
Q
Rich source of energy since they are the
most efficient way to store excess calories
because of the presence of carbon-
hydrogen bonds
A
lipids
9
Q
Integral part of cell membranes and has important
structural roles: physical properties
Precursor for steroid hormones, prostaglandins,
leukotrienes, and lipoxins
○ steroid hormones (estrogen and
testosterone)
Transported in the form of LIPOPROTEINS
A
LIPIDS
10
Q
lipids are _____ in water
A
INSOLUBLE
11
Q
LIPIDS are ______ in organic solvents
■ such as chloroform and ether
■ NON POLAR in nature because
they are soluble in non-polar
solvents
A
SOLUBLE IN ORGANIC SOLVENTS
12
Q
LIPIDS are Transported by proteins in the blood as
A
LIPOPROTEINS
13
Q
● Energy storage
● Hormone receptors
● Cell membrane structure
● Fuel
● Aid in digestion
● Act as insulator to allow nerve conduction
A
LIPIDS
14
Q
a. Neutral Fats - Triglycerides
b. Waxes
A
SIMPLE LIPIDS
15
Q
a. phospholipids
b. glycolipids
c. sulfolipids
d. lipoproteins
A
CONJUGATED
16
Q
a. fatty acids
b. glycerol
c. cholesterol
d. VIT A,E,K
A
derived lipids
17
Q
Lipid profile includes which of the following?
a.Total cholesterol, total protein, HDL, LDL
b. Total cholesterol, triglyceride, HDL, CRP
c. Total cholesterol, total protein, HDL, LDL
d. Total protein, triglyceride, HDL, LDL
A
C
18
Q
what are the major lipids?
A
FPTC
FATTY ACIDS - derived
PHOSPHOLIPIDS- conjugated
TRIGLYCERIDES- simple
CHOLESTEROL - derived
19
Q
Linear chains of C-H bonds that terminate with a
carboxyl group(-COOH)
A
FATTY ACIDS
20
Q
RCOOH(R is an ____chain)
A
alkyl chain
21
Q
side chain: 4-6C
A
SHORT 4-6
22
Q
side chain: 8-12C
A
MEDIUM 8-12
23
Q
side chain: more than 12C
A
long
24
Q
no double bond
A
saturated
example: palmitic
25
one double bond
monoUNSATURATED
oleic acid
26
>2 double bonds
polyunsaturated
linoleic
linolenic
27
Both H+ atoms on the same side of the C=C bonds
CIS
28
This arrangement causes a “bend” on the molecular
structure of UFA
CIS
29
Advantages of the “bends” in UFA
○ Increases the space that UFAs require when
packed in a lipid layer
○ Makes UFAs more fluid
CIS
30
With both H+ atoms on opposite sides of the C=C
double bond
TRANS
31
Because of the orientation of the double bonds, _____ UFAs do not bend
TRANS
32
If UFAs do not bend:
They act like saturated FA
Their physical properties behave like SFA
33
● Not commonly found in nature
● Mostly found in our diet
TRANS FA
34
Major dietary trans FA:
ELAIDIC ACID (18 carbon with one double bond)
35
Source: _______ treatment used in
food processing
Chemical hydrogenation
36
Increases the viscosity of oils
■ Causes “hardening” of fat
■ Converts polyunsaturated plant oils
into solid margarine – producing
“trans double bonds”
chemical hydrogenation
37
Consumption of trans FAs increase the risk of
coronary heart disease(CHD)
TRUE
38
HIGH LDL
LOW HDL
TRUE
39
Precursor of eicosanoids
POLYUNSATURATED FA
40
first double bond is on the third
position
OMEGA 3
41
first double bond is on the sixth
position
OMEGA 6
42
first double bond is on the ninth
position
OMEGA 9
43
Consumption of cis Fas increases the risk of coronary heart disease?
FALSE ; TRANS DAPAT
44
● Most abundant lipid in man
● Originates in the liver and intestine
PHOSPHOLIPIDS
45
Contain two FAs and a phospholipid head group
(amphipathic)
PHOSPHOLIPIDS
46
fatty acid part of phospholipids is ____ and found in the middle of
HYDROPHOBIC
47
head of phospholipids is ______ and ; facing
outwards toward the aqueous
environment
HYDROPHILIC
48
Synthesized in the cytosolic compartment of all
organs of the body, especially in the liver.
phospholipid
49
Main component of lipid bilayer
Lung surfactant
phospholipid
50
1. Choline / phosphatidyl choline
2. Inositol
3. Inositol phosphates
4. Glycerol
5. Serine
6. Ethanolamine
types of phospholipid head groups
51
major phospholipids
1. lecithin - 70%
2. sphinhomyelin - 20%
3. cephalin - 10%
52
most common phospholipid
head group:
lecithin
choline
53
derived from an amino alcohol called
sphingosine
Essential component of cell membranes
(RBC and nerve sheath)
headgroup:____
sphingomyelin
phosphocholine or sphingosine
54
ethanolamine / amino acid SERINE attached
to ethanolamine as a headgroup
cephalin
ethanolamine
55
Most phospholipids are derived from
glycerol
56
Only ________ is derived from amine alcohol
sphingomyelin
57
most abundant phospholipids in the body
phosphatidylcholine
phosphatidylethanolaminw
58
First practical chemical test to assess fetal pulmonary status
lecithin/sphingomyelin (l/s ratio)
59
Concentrations of sphingomyelin remain constant
throughout the pregnancy, and levels of lecithin are
increasing.
TRUE
60
L/S ratios greater than 2.0 usually indicate
MATURITY = GREATER
61
L/S ratios less than 1.5 indicate
IMMATURITY LESS THAN
62
serves as a reference analyte during
3rd trimester of pregnancy because its concentration
is constant as opposed to lecithin.
sphingomyelin
63
Q3. L/S ratio of 1.2 means
delay in lung maturation
64
Contain three FA attached to one molecule of glycerol
○ Looks like phospholipid but has 3 fatty acids
instead of 2
Consumed and synthesized by the liver
triglycerides
65
Main source of energy
Storage form of lipids in the humans
Triglycerides
66
Broken down by lipase, cortisol, and epinephrine
● Associated with acute pancreatitis
triglycerides
67
No bends in their
structure;
SFA
68
pack together tightly “solid” at RT
SFA
69
With bends;
CIS UFAs
70
oils at RT; “liquified”
cis UFAs
71
_____sources are “solids” at RT
animal sfa
72
_____ sources are rich in poly-UFA; are “oils/liquids” at
RT
PLANT cis UFAs
73
Unsaturated steroid alcohol containing 4 rings and a
single C-H side chain
cholesterol
74
4 rings of cholesterol (A,B,C,D)
perhydro cyclopentano phenanthrene
cyclopentano perhydro phenanthrene
75
Nucleus: tetracyclic
27 carbon atoms
Amphipathic
cholesterol
76
The only hydrophilic part of cholesterol is the
hydroxyl part of the _____
A RING HYDROPHILIC
77
Cholesterol is mostly
HYDROPHOBIC
78
● Precursor of hormones (steroids)
○ Precursor for estrogen and testosterone
● Source of bile acids
○ Bile acids act as detergent, helping fat
absorption in the intestines
● Converted to Vitamin D3
○ Small portion of cholesterol is converted in
the skin by irradiation from the sunlight
CHOLESTEROL
79
evaluates the risk for
atherosclerosis, myocardial and coronary arterial
occlusions
serum cholesterol
80
The incidence of heart disease is strongly associated with serum cholesterol concentration
TRUE
81
are important for coronary heart disease and
for assessing lung maturation.
lipids
82
exogenous source
diet
83
endogenous source
liver
84
Normal healthy adults synthesize – approximately
1 g/day
85
Consume approximately
0.3g/day
86
is maintained in serum by controlling
the level of de novo synthesis (endogenous
production)
150-200 mg/day
87
two forms of cholesterol
cholesteryl ester - 70%
free cholesterol -30%
88
Also called esterified cholesterol
○ Once cholesterol is esterified, it becomes
completely or purely hydrophobic, unlike free
cholesterol
CHOLESTEROL ESTER HYDROPHOBIC
89
○ Free cholesterol is _______ . It still has
OH attached to A ring, making it the
hydrophilic portion
amphipathic
90
Inactive form of cholesterol with protective “property” and stored in cells
Absence of polar groups
Hydroxyl group is conjugated by an ester bond to a
fatty acid, same way as in TAG
cholesterol ester
91
Location: Central of intracellular lipid droplets or
hydrophobic core of lipoproteins
cholesterol ester
92
With polar groups (the hydroxyl group attached to the A ring)
● Active form of cholesterol with cytotoxic property
free cholesterol
93
Location: surface of lipid layers
free cholesterol
94
The process of esterification is a
detoxification step
95
To reduce the accumulation of cholesterol
through the action of the acyltransferase
enzymes
LCAT AND ACAT
lecithin:cholesterol acyltransferase
acylcholesterol acyltransferase
96
Esterified cholesterol is purely hydrophobic. This
statement is:
a. True
b. False
TRUE
97
is a derivative of cholesterol in which
an ester bond is formed between
the carboxylate group of a fatty
acid and the hydroxyl group of
cholesterol
cholesteryl ester
98
Cholesterol absorption happens in the
Site: jejunum to terminal ileum (in small intestine
99
Absorption by active process using
enterocyte protein ________
inhibited by ezetimibe
NPC1L1
100
If you have elevated cholesterol,
and the source of elevation is
exogenous, doctor prescribes
ezetimibe
101
most important
factor affecting micelle formation
bile acids (amphipatic)
102
are derived from lipids, and main
purpose is to act as a detergent, to
enhance fat absorption
bile acids
103
Absorption of plant sterols and other sterols is limited ______ transporters on enterocytes: pumps
excess sterols back to the lumen for excretion
ABCG5/G8
104
marked increase in plasma
and tissue concentrations of plant sterols
(high risk for CHD)
sitosterolemia
105
After absorption, ______ are assembled
(exogenous pathway)
is one of the major
lipoproteins
chylomicrons
106
needed in the formation and
secretion of chylomicrons
APO B-48
107
excess lipid
in enterocytes and fat malabsorption
chylomicron retention disorder
108
Lymphatics → Thoracic duct → Systemic
venous circulation
True
109
Endogenous synthesis of cholesterol will
acetate
acetyl-coA
110
End-product of stage 1 is
3-hydroxy-3-methylgutaryl-coA
111
rate limiting enzyme in cholesterol biosynthesis
3-hydroxy-3-methylglutaryl-coA REDUCTASE
HMG-coA
112
second site for
cholesterol synthesis regulation
geranyl transferase enzyme
113
End-product in stage 2
SQUALENE
114
End-product of stage 3 is
cholesterol found in ER
115
Binds to VLDL (endogenous pathway)
APO B 100
116
Inhibits the final step in endogenous
synthesis of cholesterol
○ It inhibits Desmosterol to cholesterol
TRIPARANOL
117
The problem is this drug does not
inhibit HMG-CoA reductase
■ What happens is there is an
accumulation of desmosterol, and
this is the side effect of the drug.
triparanol
118
Accumulation of
______leads to
cataracts, alopecia, and
accelerates
atherosclerosis
desmosterol
119
This process is important in enhancing the
lipid carrying capacity of lipoproteins both in
the plasma and intracellularly
cholesterol esterification
120
what enzyme in plasma
LCAT
lecithin-cholesterol acyltransferase
121
what enzyme in cell
ACAT
acylcholesterol acyltransferase but requires
THIO ENZYME A (coASH)
122
cholesterol catabolism starts with enzyme
LAL
lysosomal acid lipase
123
absence of the LAL
causing accumulation of CE and TG
wolmans disease
124
Which of the following is needed in esterifying
cholesterol in plasma?
lecithin cholesterol acyltransferase
125
Which is the best enzyme to target in decreasing
cholesterol produced endogenously?
HMG-coa reductase
3-hydroxy-3-methylglutaryl-coA
126
Ezetimibe is the drug of choice to lower exogenous
cholesterol absorption. This targets which of the following:
NPC1L1
127
Cholesterol biosynthesis starts from
a. The diet
b. Acetate
c. Squalene
d. Steroids
b. acetate
128
formation of mixed micelles
UEC = unesterified cholesterol
FA
PL = phospholipids
monoglycerides
conjugated bile acids
129
for chemical absorption: transportation to
luminal cell surface
