PART 1 Flashcards
1
Q
*essential in energy metabolism of the
body
*clinically important in the diagnosis of
coronary heart disease
A
Lipids and Lipoproteins
2
Q
Total Cholesterol, Triglyceride, HDL-C, LDL-C
A
Cardiac Profile Test
3
Q
Cardiac Profile Test
A
TC, TG, HDL, LDL
Total Cholesterol, Triglyceride, HDL-C, LDL-C
4
Q
CK-MB
A
Creatine Kinase MB Isoenzyme
5
Q
*commonly known as fats
*rich source of energy and efficient way to store
excess calories: CH-Bonds
A
LIPIDS
6
Q
CK-MB, Troponin, LDH, SGOT/AST, CRP
Creatine Kinase MB Isoenzyme, Troponin I, C, D, Lactate Dehydrogenase, Serum Glutamic Oxaloacetic Transaminase (AST - aspartate aminotransferase), C-Reactive Protein
A
Other tests for Cardiac Profile Test
7
Q
*integral part of cell membranes and has important
structural roles: physical properties
* precursor for steroid hormones, prostaglandins,
leukotrienes, and lipoxins
A
LIPIDS
8
Q
Lipid is transported in
the form of ______________
A
LIPOPROTEINS
9
Q
Characteristics of Lipids
A
- Insoluble in water
- Soluble in organic solvents (chloroform and ether) (nonpolar in nature)
- Transported by proteins in
the blood as lipoproteins
10
Q
Steroid Hormones
A
Estrogen, Testosterone
11
Q
*energy storage (CH bonds)
*hormone receptors
*cell membrane structure
*fuel
*aid in digestion
*act as insulator to allow nerve
conduction
A
Functions of Lipids
12
Q
Functions of Lipids
A
*energy storage (CH bonds)
*hormone receptors
*cell membrane structure
*fuel
*aid in digestion
*act as insulator to allow nerve
conduction
13
Q
Lipid Profile
A
TC, TG, HDL, LDL
14
Q
3 Classification of Lipids
A
- Simple
- Conjugated (polar)
- Derived
15
Q
Simple Lipids
A
A. Neutral fats - Triglycerides
B. Waxes
16
Q
Conjugated Lipids (polar lipids)
A
A. Phospholipids (lipid + phosphoric acid)
B. Glycolipid – (lipid + carbohydrate) cerebrosides, globosides, gangliosides
C. Sulfolipids - contain a sulfate radical.
D. Lipoprotein (lipid with proteins)
17
Q
Derived Lipids
A
A. Fatty acids
B. Glycerol
C. Cholesterol and other steroid (Vit. D)
D. Vitamins K, A, E (fat soluble vitamins)
18
Q
MAJOR LIPIDS
A
*Fatty acids (saturated/unsaturated)
*Phospholipids
*Triglycerides
*Cholesterol (4 rings)
19
Q
FATTY ACIDS
A
*linear chains of C-H bonds that terminate with a carboxyl group (-COOH)
* RCOOH (R is an alkyl chain)
20
Q
carboxylic acid with a long aliphatic tail
A
FATTY ACIDS
21
Q
Linear chains of carbon hydrogen bonds terminating with COOH
A
Aliphatic Tail
22
Q
Steric Acid (18 carbons)
Component of Animal Fat
Solid at Room Temp
A
Saturated Fatty Acid
23
Q
Oleic Acid (18 carbons)
Component of Olive Oil
Liquid at Room Temperature
A
Monounsaturated Fatty Acid
24
Q
CLASSIFICATION OF FATTY ACID
SIDE CHAIN & SATURATION
A
*Side chain: short (4-6 C), medium (8-12 C), long
(more than 12 C)
*Saturated; monounsaturated; polyunsaturated
25
Classification based on C=C bonds
Saturated - NO double bonds
Monounsaturated - 1 double bond
Polyunsaturated - >= 2 double bond
26
Saturated has how many double bonds?
0
27
Palmitic acid
Saturated
27
Oleic acid
Monounsaturated
28
Linoleic acid and Linolenic acid
Polyunsaturated
28
2 types of C=C Double Bond of UFA (configuration)
1. cis-configuration
2. trans-configuration
29
*Both H+ atoms on the same side
of the C=C bonds
✓This arrangement causes a
“bend” on the molecular structure of UFA
Cis-configuration
30
✓ It increases the space that UFAs require when packed in a lipid layer
✓ It makes the UFAs more fluid
Advantages of the “bends” in UFA
31
What causes the bend?
Two neighboring hydrogens repel each other, causing the carbon chain to bend
32
*With both H+ atoms on opposite
sides of the C=C double bond
✓Because of the orientation of the
double bonds, trans UFAs do not bend
trans-configuration
33
What happen when trans UFAs do not bend?
✓They act like saturated FA
✓Their physical properties behave like SFA
34
* Not commonly found in nature
* Mostly found in our diet
* Source: Chemical hydrogenation treatment used in food processing
* Major dietary trans FA: Elaidic acid (18-carbon with one double
bond)
Trans fatty acid
35
✓ It increases the viscosity of oils
✓ It causes “hardening” of fat
✓ It converts polyunsaturated plant oils into solid margarine – producing “trans double
bonds”
Chemical hydrogenation of Trans Fatty Acid
36
Consumption of trans FAs increase the risk of coronary
heart disease (CHD).
✓High LDL
✓Low HDL
TRUE
37
* Precursor of eicosanoid
* Function: Vital in the structure and function of most biological
membranes
Polyunsaturated Fatty acid
38
Classification of Polyunsaturated Fatty Acid
1. Omega-3
2. Omega-6
3. Omega-9
Based on position of the first double band from the Omega terminal methyl group of the FA
39
Polyunsaturated FA are classified based on the:
✓ position of the first double bond from the terminal (omega)
methyl group of the FA chain
40
Polyunsaturated Fatty acid are precursor of?
eicosanoids
41
* most abundant lipid in man
* Originates in the liver and intestine
* contain 2 FAs and a phospholipid head group (amphipathic)
PHOSPHOLIPIDS
42
* synthesized in the cytosolic compartment of all organs of the
body, especially in the liver.
* main component of lipid bilayer
* lung surfactant
PHOSPHOLIPIDS
43
1. Choline
2. Inositol
3. Inositol phosphates
4. Glycerol
5. Serine
6. Ethanolamine
Types of Phospholipid Head Groups
(hydrophilic in nature)
44
Consumption of cis fatty acid increases risk of coronary heart disease
FALSE, should be trans
45
Amphipathic
one hydrophilic head and one hydrophobic tail
46
Fatty acid portion of the Phospholipid is __________
hydrophobic area
47
Acts as a lung surfactant
Phospholipid
48
Phospholipid with choline head
phosphatidylcholine
49
Phospholipid with Inositol head
phosphatidylinositol
50
Phospholipid with Serine head
phosphatidylserine
50
Phospholipid with Ethanolamine head
phosphatidylethanolamine
50
3 Major Phospholipids
1. Lechithin (70)
2. Sphingomyelin (20)
3. Cephalin (10)
51
✔ derived from an amino alcohol called sphingosine (head group)
✔ Essential component of cell membranes (RBC and
nerve sheath)
Sphingomyelin
52
Head group of lecithin
choline
53
Most common phospholipid present on lipoproteins and cell membranes
Lecithin
54
Head group of cephalin
ethanolamine / amino acid serine attached to the head group
55
lecithin also known as?
phosphatidyl choline
56
only sphingomyelin is derived from amino alcohol; the rest are derived from?
TRUE; glycerol
57
most
abundant phospholipids in the body
1. phophatidylcholine
2. phosphatidylethanolamine
58
Phospholipid are also important in assessing fetal pulmonary status
TRUE
59
*first practical chemical test to assess PULMONARY STATUS
*concentrations of sphingomyelin remain
constant throughout the pregnancy, and
levels of lecithin are increasing
Lecithin/sphingomyelin (L/S)
ratio
60
L/S ratios greater than 2.0 usually indicate?
maturity; lungs are developing properly
61
ratios less than 1.5 indicate?
immaturity; delay in lung maturation
62
Sphingomyelin serves as a reference analyte during 3rd trimester of pregnancy because its concentration is constant as
oppose to lecithin.
TRUE
63
*contain 3 FA attached to one molecule of
glycerol
- consumed and synthesized by the liver
- main source of energy
- storage form of lipids in the humans
- broken down by lipase, cortisol and ephinephrine
TRIGLYCERIDES
64
With bends; form oils at RT; “liquified”
cis-unsaturated FA triglyceride
65
No bends in their structure; pack together
tightly “solid” at RT
saturated FA triglyceride
66
TAG from plants are rich in poly-UFA; are “oils/liquids”
at RT
TRUE
67
TAG from Animal sources are “solids” at RT
TRUE
68
solid in RT: saturated FA (from animals)
SSA TRUE
69
oil in RT: unsaturated FA (from plants)
OUP TRUE
70
*unsaturated steroid alcohol
containing 4 rings (A,B,C,D) and a
single C-H side chain
*27 carbon atoms
*amphipathic
CHOLESTEROL
71
Nucleus of cholesterol is the 4 rings called:
_________________________
cyclopentanoperhydrophenanthrene OR tetracyclic perhydrocyclopentanophenanthrene
72
phospholipid and cholesterol are both?
amphipathic
73
cholesterol as amphipathic means
hydrophobic - 4 rings
hydrophilic - hydroxyl group at the A-ring
74
✓Precursor oh hormones (steroids)
✓Source of bile acids
✓Converted to vitamin D3
Functions of cholesterol
75
▪ Serum cholesterol evaluates the risk for atherosclerosis,
myocardial and coronary arterial occlusions.
▪ The incidence of heart disease is strongly associated
with serum cholesterol concentration.
Diagnostic significance of Cholesterol
76
Important for FAT ABSORPTION
Bile Acids
77
Steroid hormones
estrogen and testosterone
78
Cholesterol to Vit. D3 in skin via radiation to sunlight
TRUE
79
Triglyceride is associated with?
pancreatitis
80
Cholesterol is associated with?
heart disease
81
Phospholipid is associated with?
lung maturity
82
Sources of Cholesterol
1. exogenous (diet)
2. endogenous (liver)
83
* Normal healthy adults synthesize --
approximately 1g/day.
* consume approximately 0.3g/day
* 150 - 200 mg/dL is maintained in
serum by controlling the level of de novo synthesis (endogenous production)
Cholesterol
84
2 forms of cholesterol
1. cholesteryl ester/esterified cholesterol - 70% (hydrophobic)
2. free cholesterol - 30% (amphipathic)
85
cholesteryl ester also known as?
esterified cholesterol or neutral lipid (also triglyceride)
86
- no hydroxyl
- no hydrophilic
- esterified
- purely hydroPHOBIC
cholesteryl ester/esterified cholesterol
87
✓a.k.a Neutral lipid
✓Absence of polar groups
✓Inactive form of cholesterol with “protective” property and stored in
cells.
Cholesterol ester – 70%
88
✓Hydroxyl group is conjugated by an ester bond to a fatty acid, same way
as in TAG
Cholesterol ester – 70%
89
✓With polar groups (hydroxyl)
✓Active form of cholesterol with CYTOTOXIC property
✓Location: Surface of lipid layers
Free cholesterol – 30%
90
✓Location: Center of intracellular lipid droplets or hydrophobic core of
lipoproteins
Cholesterol ester – 70%
91
The process of esterification is a “_________” step
✓ to reduce the accumulation of free cholesterol through the
action of the acyltransferase enzymes (LCAT and ACAT)
DETOXIFICATION
92
Enzymes for Esterification
LCAT and ACAT
93
____ is a compound of the sterol type found in most body tissues
(free) cholesterol
94
_______ 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
95
structure: contains sterol with hydroxyl
cholesterol
96
structure: contains esterified structure with nonpolar groups
cholesteryl ester
97
polarity: amphipathic
cholesterol
98
polarity: hydrophobic and nonpolar
cholesteryl ester
99
solubility in water: sparsely soluble
cholesterol
100
solubility in water: insoluble
cholesteryl ester
101
form: active raw form
cholesterol
102
form: inactive form
cholesteryl ester
103
Cholesterol Absorption Site
small intestine: jejunum and terminal ileum
104
* Formation of mixed micelles (UEC, FA, monoglycerides, PL, and
conjugated bile acids)
* Transportation to luminal cell surface
* Absorption by active process using enterocyte protein
NPC1L1 (inhibited by ezetimibe)
Cholesterol Absorption
105
mixed micelles contains..
UEC, FA, monoglycerides, PL, and conjugated bile acids
106
Absorption by active process using _________ (inhibited by ezetimibe)
enterocyte protein NPC1L1
107
Absorption by active process using enterocyte protein NPC1L1 (inhibited by ______ ) (EXOGENOUS - DIET)
ezetimibe
108
most important factor affecting micelle
formation
bile acids (amphipatic) are derived from lipids; purpose is to facilitate fat absorption
109
*Quantity of dietary cholesterol that can be absorbed depends on
the amount that can be solubilized by micelles
TRUE
110
Absorption of plant sterols and other sterols is limited
by ______ on enterocytes: pumps excess sterols back to the lumen for excretion
ABCG5/G8 transporters
111
marked increase in plasma and tissue concentrations of plant sterols (high risk for CHD)
sitosterolemia
112
After absorption, ______ are assembled
(exogenous pathway)
chylomicrons
113
one of our major lipoproteins and responsible for exogenous pathway (diet)
chylomicrons
114
needed in the formation and secretion of
chylomicrons; protein component
Apo lipoprotein B-48
115
excess lipid in enterocytes and fat malabsorption
Chylomicron retention disorder
115
lymphatics – thoracic duct – systemic venous circulation
pathway of cholesterol
116
Cholesterol Synthesis has 3 stages
TRUE
117
* from acetate/acetyl co-enzyme A
* important in the
discovery of
treatment to
lower cholesterol
* all cells: 90%
from liver and gut
CHOLESTEROL SYNTHESIS STAGE 1
118
CHOLESTEROL SYNTHESIS STAGE 1 COMPONENTS
Acetyl-CoA
|
Acetoacetyl CoA
|
3-Hydroxy-2-methylglutaryl-CoA (HMG-CoA)
119
End product of Stage 1
3-Hydroxy-2-methylglutaryl-CoA (HMG-CoA)
119
- Contains the step
involving HMG-CoA reductase: rate
limiting enzyme in
cholesterol
biosynthesis
- Geranyl transferase
enzyme: second site
for cholesterol
synthesis regulation
CHOLESTEROL SYNTHESIS STAGE 2
120
rate limiting enzyme in
cholesterol
biosynthesis
HMG-CoA reductase
121
blocking HMG-CoA reductase can prevent synthesis of cholesterol
-statin; atorvastatin, simvastatin
122
second site
for cholesterol
synthesis regulation
Geranyl transferase
enzyme
123
End product of Stage 2
Squalene
124
CHOLESTEROL SYNTHESIS STAGE 3
* in Endoplasmic Reticulum
* final product: 27-carbon molecule cholesterol
* binds to VLDL (endogenous
pathway)
*__________
125
Inhibits the final step in endogenous cholesterol synthetic pathway (Desmosterol)
Triparanol
126
End product of Stage 3
Cholesterol
127
Triparanol does not inhibit HMG-CoA reductase, cause accumulation of Desmosterol
128
Accumulation of Desmosterol results in?
- cataracts
- alopecia
- accelerated atherosclerosis
129
Best to target? via -statins
HMG-CoA reductase
130
LCAT means?
lecithin cholesterol acyl transferase
131
Esterification in plasma
LCAT
132
ACAT means?
acylcholesterol acyltransferase
133
Esterification in intracellular cells
ACAT
134
ACAT requires?
thio coenzyme A (CoASH)
135
Fatty Acid + CoASH -> Acyl-CoA
via Acyl CoA synthetase
Acyl-CoA + cholesterol -> cholesterol ester + coASH
via ACAT
Intracellular
136
Lecithin + cholesterol -> cholesterol ester + lysolecithin
via LCAT
Intravascular (Plasma)
137
*Hydrolysis with lysosomal acid lipase
*Cholesteryl ester storage disease or Wolman's disease:
absence of the LAL causing accumulation of CE and
TG
Cholesterol Catabolism
138
absence of the LAL causing accumulation of CE and
TG
Wolman's disease
139
Fate of cholesterol in the liver (Cholesterol Catabolism)
*secreted into bile
*metabolized to bile acids: cholic and chenodeoxycholic acid (conjugated with glycine or taurine)
*re-secreted on lipoproteins
140
Enzyme to catabolize/hydrolize cholesterol
lysosomal acid lipase (LAL)
141
