Lipids MCQ - Biotechnology Engineering (BT) MCQ

Heart is the organ that derives most of its energy from the β oxidation of fatty acids.

The wax from the plant origin was first and most abundantly extracted from Jojoba plant.
Lanolin (from Latin lana ‘wool’, and oleum ‘oil’), also called wool wax or wool grease, is a wax secreted by the sebaceous glands of wool-bearing animals.
Shellac is a resin secreted by the female lac bug, on trees in the forests of India and Thailand.
Spermaceti (from Greek sperma meaning “seed”, and ceti, the genitive form of “whale”) is a waxy substance found in the head cavities of the sperm whale.

Lipids are a class of biomolecules that is defined by their solubility in organic solvents, such as chloroform, and their relative insolubility in water. Interactions among lipids and of lipids with other biomolecules arise largely from their hydrophobic (“water-hating”) nature.
Option (a) is incorrect as TAG (triacylglycerol) are a class of lipids which are triesters of fatty acid with glycerol.
Option (b) is incorrect as fatty acids are long chain carboxylic acids. 

A saturated fat is a type of fat in which the fatty acid chains contains all single bonds Examples: Lauric, Myristic, palmitic and stearic acids.

In unsaturated fatty acids there is at least one double bond in the fatty acid chain example: timnodonic acid, palmitoleic acid, oleic acid, myristoleic acid, linoleic acid, and arachidonic acid.

Adipose tissue is specialized connective tissue that functions as the major tissue for storage of fat in the form of triglycerides.

Lecithin and cephalin are glycerophospholipids.The are abundant in brain and nerve tissues. Lecithin contains choline and cephalin contains serine.  Lecithin is a mixture of phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol. Cephalin is a mixture of phosphatidylethanolamine and phosphatidyl serine.

It is plasmalogen with ether linkage at C1 and glycerol at C2.Platelet-activating factor, also known as PAF, PAF-acether or AGEPC (acetyl-glyceryl-ether-phosphorylcholine), is a potent phospholipid activator and mediator of many leukocyte functions, platelet aggregation and degranulation, inflammation, and anaphylaxis.

A ganglioside is a molecule composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (N-acetylneuraminic acid) linked on the sugar chain.
GM (Monosialotetrahexosylganglioside),
GD (Disialotetrahexosylganglioside)
GT (Trisialotetrahexosylganglioside)
the “prototype” ganglioside, is a member of the ganglio series of gangliosides which contain one, two and three  sialic acid residue respectively.

An oil that thickens or hardens on exposure to air, especially one used by artists in mixing paint. For example-linseed oil, tung oil, poppy seed oil, perilla oil and walnut oil.

Neutral fats (Triglycerides) are composed of fatty acid hydrocarbon chain bonded to a single glycerol molecule. The unsaponifiable fraction of fatty substances includes all the components that after a process called alkaline hydrolysis are barely soluble in aqueous solutions, but are soluble in organic solvents.

Unsaturated fatty acids are consist of alkene as functional group and oleic acids are the only option which consist of double bond (or alkene).

All of the lipid molecules in cell membranes are amphipathic (or amphiphilic)—that is, they have a hydrophilic (“water-loving”) or polar end and a hydrophobic (“water-fearing”) or nonpolar end. The most abundant membrane lipids are the phospholipids, which consist of both phosphate group (polar) and lipids (non-polar).

Eicosanoids and Triacylglycerol are not amphipathic in nature, and not present in membrane.

Upon activation by phospholipases, phosphoionositol lipids break down into two components a. Diacylglycerol that activates PKC and another IP3 that activates calcium signalling.

Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).  These two fatty acids cannot be synthesized by humans because humans lack the desaturase enzymes required for their production. The double bonds present naturally in fatty acids  are  in " cis " configuration. There are three classes of eicosanoids: prostaglandins, thromboxanes, and leukotrienes.  All eicosanoids are derived from arachidonic acid , the 20-carbon polyunsaturated fatty acid. Cortisol (Glucocorticoid released from adrenal cortex), Aldosterone (Mineralcorticoid released from adrenal cortex) and testosterone (Male sex hormone released by testis) are all derived from cholesterol.

Out of 70 Kg 10 kg is fat , so remaining wt = 60 kg
Energy produced by 10 kg fat = 10,000 x 9 kcal=90,000Kcal
Amount of glucose needed to produce same amount of energy = 90,000/4 = 22,250 g or 22.5 kg
Hence total weight of the person with same level of energy reserve as glucose will be
60 + 22.5 = 82.5 kg

As a matter of fact there are 8 asymmetric carbon atoms in the cholesterol. Therefore total number of isomers will be 2⁸ = 256

Amount of KOH required = 47.5 x 10^-3/ 56g mole = 8.482 x 10^-4 moles
It takes 3 moles of KOH for each mole of triglyceride
Amount of triglyceride present = 8.482 x 10^-4/3 = 2.828 x 10^-4moles
No. of moles = wt/MW or MW = wt/no. of moles
MW = 250 x 10^-5/2.827 x 10⁴ = 884

0.578 g of I₂/0.680 g oil = Wt I₂/894 g oil
Wt I₂ absorbed = (884)(0.578)/(0.680) = 751.4 g I₂ per mole of oil
MW of I₂ = (2) (126.9) = 253.8
751.4 g I₂ / 253.8 g/mole = 2.96 moles I₂/mole of oil
Thus on average there are three double bond per molecule of triglyceride.