Q-1. Which of the following is a cardio-protective fatty acid?
a) Palmitic acid
b) Stearic acid
c) Oleic acid
d) Omega 3 fatty acids
Answer: Omega 3 fatty acids
Explanation:
Omega 3 fatty acids are cardio-protective fatty acids.
Q-2. Maximum source of linoleic acid
a) Coconut oil
b) Sun flower oil
c) Palm oil
d) Vanaspati oil
Answer: Sun flower oil
Explanation:
Linoleic acid is nutritionally essential fatty acids maximally found in Safflower > Corn oil > Sun flower
Q-3. Glyco-sphingo-lipid made up of
a) Glucose
b) Glycerol
c) Sphingosine
d) Fatty acids
e) Thromboxane A2
Answer: a, c and d
Explanation:
Glyco-sphingo-lipid made up of ceramide and one or more sugars.
Ceramide further consist of sphingosine and fatty acid.
Important point:
Gangliosides are complex glycosphingolipids derived from gluco-syl-ceramide that contain additional one or more molecules of a sialic acid.
Q-4. Gangliosides consists of
a) LCFA
b) Alcohol sphingosine
c) Phosphate
d) Sialic acid
e) Glycerol
Answer: a, b and d
Explanation:
See above explanation.
Q-5. Alcohol group is found in
a) Ganglioside
b) Sphingomyelin
c) Cerebroside
d) Terpen
Answer: a, b and c
Explanation:
Q-6. The most essential fatty acid is
a) Linoleic acid
b) Linolenic acid
c) Arachidonic acid
d) Palmitic acid
Answer: Linoleic acid
Explanation:
Essential fatty acids:
Arachidonic acid
Linoleic acid
Linolenic acid
Important point:
Linoleic and Linolenic acid are the only fatty acids known to be essential for complete nutrition in human and known as nutritionally essential fatty acids. Arachidonic acid can be formed from Linoleic acid.
Q-7. Essential fatty acids are all except
a) Palmitic acid
b) Arachidonic acid
c) Linoleic acid
d) Linolenic acid
Answer: Palmitic acid
Explanation:
Essential fatty acids:
Arachidonic acid
Linoleic acid
Linolenic acid
Important point:
Linoleic and Linolenic acid are the only fatty acids known to be essential for complete nutrition in human and known as nutritionally essential fatty acids. Arachidonic acid can be formed from Linoleic acid.
Q-8. Membrane fluidity is increased by (AIIMS May 2005)
a) Stearic acid
b) Palmitic acid
c) Cholesterol
d) Linoleic acid
Answer: Linoleic acid
Explanation:
Lipids with shorter chains are less stiff and less viscous because they are more susceptible to changes in kinetic energy due to their smaller molecular size and they have less surface area to undergo stabilizing van der Waals interactions with neighboring hydrophobic chains.
Lipid chains with double bonds are more fluid than lipids that are saturated with hydrogen and thus have only single bonds. On the molecular level, unsaturated double bonds make it harder for the lipids to pack together by putting kinks into the otherwise straightened hydrocarbon chain.
Examples of unsaturated fats are palmitoleic acid, oleic acid, linoleic acid, and arachidonic acid.
Cholesterol acts as a bidirectional regulator of membrane fluidity because at high temperatures, it stabilizes the membrane and raises its melting point, whereas at low temperatures it intercalates between the phospholipids and prevents them from clustering together and stiffening.
Q-9. Which of these fatty acids is found exclusively in breast milk?
a) Linoleate
b) Linolenic
c) Palmitic
d) Docosahexaenoic acid
Answer: Docosahexaenoic acid
Explanation:
Docosahexaenoic acid (DHA) which is synthesized to a limited extent from alpha Linolenic acid or obtained directly from fish oils is present in high concentration in retina, cerebral cortex, testis, and sperm.
DHA is particularly needed for development of the brain and retina and is supplied via the placenta and milk.
Patients with retinitis pigmentosa are reported to have low blood levels of DHA.
Q-10. The human plasma lipoprotein containing the highest percentage of triacylglycerol by weight is
a) VLDL
b) Chylomicrons
c) HDL
d) LDL
Answer: Chylomicrons
Explanation:
Triacylglycerol content of lipoproteins:
Chylomicron: 90 %
VLDL: 60 %
LDL: 8 %
HDL: 5 %
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Q-11. Surfactant is secreted by
a) Pneumocytes-I
b) Pneumocytes-II
c) a and b
d) Macrophage
Answer: Pneumocytes-II
Explanation:
Fetuses begin to produce surfactant between weeks 24 and 28. By about 35 weeks, most babies have enough naturally produced surfactant to keep the alveoli from collapsing.
Surfactant is synthesized by alveolar epithelial type II cells and is probably secreted as a lipoprotein complex.
Pulmonary surfactant is a complex mixture of phospholipids (PL) and proteins (SP) that reduce surface tension at the air-liquid interface of the alveolus.
It is made up of about 70% to 80% PL, mainly dipalmitoylphosphatidylcholine (DPPC), 10% SP-A, B, C and D, and 10% neutral lipids, mainly cholesterol.