Functions and principal sources of lipids - class-XI
Description: functions and principal sources of lipids | |
Number of Questions: 46 | |
Created by: Sharvani Hegde | |
Tags: meaning of life biology biomolecules: chemical constituents of living cells food and it's constituents |
Cholesterol belongs to group
-
Steroid
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Neutral fats
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Waxes
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Phospholipids
Lipids are insoluble in water because lipids molecules are
-
Hydrophilic
-
Hydrophobic
-
Neutral
-
Zwitter ions
Lipids are hydrophobic (water repelling) and non-polar. Non-polar substances, for instance fats and oils cannot be dissolved in water because they have made up of only carbon-carbon and hydrogen-carbon bonds. Only polar solutes dissolve in polar solvents.
Which of these is not a lipid?
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Steroid
-
Fat
-
Polysaccharide
-
Wax
The polysaccharide is a carbohydrate that is formed by the bond formation between various monomers like glucose, fructose etc. Its examples are starch, cellulose, chitin, glycogen, etc.
Jojoba (Simmondsia) possesses
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Triglyceride and wax
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Wax
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Triglyceride
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Sterol
Which one is a lipid?
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Stachyose
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Lycopene
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Leucine
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None of the above
Stachyose is a tetrasaccharide consisting of 2 galactose, one glucose and one fructose units. It occurs naturally in green beans, soya beans and other beans. It is less sweet than sucrose. Its molecular formula is $C _{24}H _{42}O _{21}$
Lipids are classified into $3$ main types, which includes
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Simple lipids
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Compound lipids
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Derived lipids
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All of them
Lipids are classified into simple, compound and derived lipids.
- Simple lipids are esters of fatty acids with various types of alcohols.
- Compound lipids are esters of fatty acids with various types of alcohols in addition to a prosthetic group.
- Derived lipids are those produced by the hydrolysis of the first two groups.
Choose the odd one out w.r.t. polymer _____________.
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Proteins
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Lipids
-
Polysaccharides
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Nucleic acids
Proteins are made of amino acids (monomers) and polysaccharides or sugars are made of monosaccharides (monomers). Nucleic acids or DNA and RNA are made of nucleotides again monomers. However, lipids are not polymers made of smaller monomeric units.
Choose the correct answer from the alternatives given.
In a phospholipid bilayer, the
-
Phosphate groups are hydrophobic
-
Fatty acid tails are hydrophilic
-
Proteins are located only between the two layers
-
Phosphate heads are oriented towards the exterior of the cell or toward the cytoplasm
So, the correct answer is 'Phosphate heads are oriented towards the exterior of the cell or toward the cytoplasm'.
A phospholipid molecule has a head and two tails, The tails are found
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At the surfaces of the membrane
-
In the interior of the membrane
-
Spanning the membrane
-
Both (a) and (b)
So, the correct answer is 'In the interior of the membrane'.
Identify the correct statements w.r.t the given cell
A. Concerned with lipid and steroidal hormone synthesis
B. Outer non living rigid structure which gives shape to the cell and protects from mechanical damage and infection.
C. Both lie perpendicular to each other and each has an organisation like the cart wheel'
D. Responsible for trapping light energy for the synthesis of sugar.
E. Present in cells actively involved in protein synthesis and secretion..
F. Spherical structures, rich in hydrolytic enzymes.
-
A, D & E
-
B, C & D
-
A, C & E
-
A, B, C & F
The properties of lipids are
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Insoluble in water and soluble in fat solvents.
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High energy content.
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Structural component of cell membrane.
-
All of the above.
Lipids are compounds of carbon, hydrogen and oxygen where ratio of hydrogen and oxygen is less than that of water. Lipids are esters of fatty acids and alcohol which form emulsion with water but are soluble in organic solvents. Some of the common examples of lipids are butter, ghee, cholesterol, carotene etc. Lipids are used as energy source. Lipids provide 9.3 kcal per gram as compared to 4.5 kcal per gram by carbohydrates. Lipids have other important uses also like they lubricate hairs and feathers in animals, reduce transpiration in plants and form components of cell membranes in organisms.
A triglyceride molecule has?
-
Three fatty acids with one glycerol molecule
-
Three fatty acids with two glycerol molecules
-
Two fatty acids with two glycerol molecules
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One fatty acids with one glycerol molecule
The maximum number of double bonds present in essential fatty acids is
-
1
-
2
-
3
-
4
Unsaturated fatty acids have one or more double bonds like oleic acid (one), linoleic acid (two), linolenic acid (three), and arachidonic acid (four). An unsaturated fatty acid with one double bond is called mono unsaturated fatty acid (MUFA). Fatty acid with more than one double bond is called as polyunsaturated fatty acid (PUFA). Animals cannot synthesize fatty acids with double bonds (Linoleic, Linolenic and Arachidonic acids). Hence, these fatty acids must be obtained in diet and are thus called essential fatty acids.
What are lipids?
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Composed of fatty acids
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Triglycerides
-
Insoluble in water
-
All of the above
Lipids are esters of fatty acids and glycerol which form emulsion with water are soluble in organic solvents, example- ghee, butter, carotene, menthol. Fatty acids are long chains of hydrocarbon having an acidic group. Chemically, lipids are diverse and may be acidic or esters but all lipids have a common property that they are hydrophobic and insoluble in water.
Lipids are insoluble in water because lipid molecules are ______________.
-
Hydrophilic
-
Hydrophobic
-
Neutral
-
Zwitter ions
Lipids are hydrophobic means water-hating. They are water-insoluble. Lipids are non-polar molecules while water is a polar molecule, so there is no way for water to attach to a lipid molecule. Instead, the non-polar lipids will bind to themselves, which is why oils and fats form droplets on the surface of the water.
.............. cells/tissue in the body contains average of 18.5% of protein and lipids constituting 3%?
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Fat
-
Muscle
-
Bone
-
Red blood cell
The average amount of protein present in muscle is 18.5%. Lipids constitute 3% in muscle
Which of the following is the highest energy rich compound?
-
Creatinine phosphate
-
Protein
-
Carbohydrate
-
Fat
Respiration is the oxidation process in which reduced biomolecules like carbohydrates, fats, proteins etc are oxidised to release energy, which can be used for cellular processes. Fats are most reduced biomolecules and their oxidation releases maximum amount of energy. The energy released in oxidation of one gram of fat is twice the energy released in oxidation of one gram of carbohydrate. Hence, carbohydrates are used as an energy reserve biomolecules in living systems.
The structural lipids of cell are
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Phospholipids
-
Simple lipids
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Steroids
-
Chromolipids
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from sphingosine instead of glycerol.
Lipids are insoluble in water, because lipids molecules are ___________.
-
Neutral
-
Zwitter ions
-
Hydrophobic
-
Hydrophilic
Lipids are hydrophobic means water hating. They are water insoluble. Lipids are non-polar molecules while water is polar molecule, so there is no way for water to attach to a lipid molecule. Instead, the non-polar lipids will bind to themselves, which is why oils and fats form droplets on the surface of water.
Fats are also known as
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Lipids
-
Proteins
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Carbohydrates
-
Nucleic acids
Which biomolecule is made up of only carbon, hydrogen and oxygen?
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Lipids
-
Proteins
-
Carbohydrates
-
Nucleic acids
Proteins are the polymers of amino acids and have C, H, O, N and S. Carbohydrates and nucleic acids have C, H, O, N, P and S. Lipids are chemically diverse group and mostly have long hydrocarbon chain composed of C, H and O. Thus, the correct answer is A.
Maximum percentage of lipoprotein is present in
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Chylomicron
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HDL
-
VDL
-
VLDL
Sphaerosomes have
-
Cellulose reserve
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Protein reserve
-
Lipid reserve
-
Both protein and lipid reserve.
Which of the following is not a lipid?
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Wax/ lecithin
-
Sterol/ cholesterol
-
Glycerol/ maltose
-
Lecithin/ Ghee
Select the wrong statement?
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The protein part of the holoenzyme is called the apoenzyme
-
Thylakoids are arranged one above the other like stack of coins forming a granum
-
Building blocks of lipid are amino acids
-
Cross-over occurs at pachytene stage of meiosis I
Cofactor is a nonprotein part of the enzyme. It can be metal ions or the organic chemical. The cofactors which are organic chemicals are known as coenzyme. These are loosely attached to the apoenzyme. The tightly bound coenzymes are prosthetic group.
Number of oxygen atoms in lipid molecules is always ......... as compared to number of carbon atoms
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Less
-
More
-
Equal
-
Double
Which of the following lipid is essential part of good diet?
-
Oleic acid
-
Linoleic acid
-
Stearic acid
-
Palmitic acid
Structural lipids of cell membrane are
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Simple lipid
-
Chromolipid
-
Phospholipid
-
Steroid
Which fatty acid is liquid at room temperature?
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Palmitic acid
-
Stearic acid
-
Lauric acid
-
Linoleic acid
Steroids are
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Lipids
-
Proteins
-
Vitamins
-
Carbohydrates
Steroids are the organic molecule which plays an important role in the growth and development of the body. The molecular structure consists of 17 carbon which is arranged in four fused structure. It is found in plants, animals, and fungi. It is considered as an important class of lipids as they have properties similar to the triglycerides. It also plays important role in defensive mechanism of the body.
Cerebroside is a
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Glycolipid
-
Sterol
-
Phospholipid
-
Steroid
Cerebroside is an important component of muscles and nerve cell membrane. It is also known as galactosylceramide. It is a class of glycolipids which consists of N -acyl sphingosine with glucose or galactose. Its deposition causes Gaucher disease. It is synthesized in endoplasmic reticulum and membranes of Golgi apparatus. It is degraded in the lysosomes. It is also known as galactolipid.
Hydrolysis of lipid yields
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Fats
-
Fatty acids and glycerol
-
Mannose and glycerol
-
Maltose and fatty acid
Most common lipids are triglycerides of glycerol and fatty acids. During digestion of lipids they are broken down into constituent fatty acids and glycerols by the action of lipase enzymes.
$a$ | Fatty acid | $1.$ | Glutamic acid |
---|---|---|---|
$b$ | Phospholipid | $2.$ | Tryptophan |
$c$ | Aromatic Amino Acid | $3.$ | Lecithin |
$d$ | Acidic Amino Acid | $4.$ | Palmitic acid |
-
$a - 1, b - 2, c - 3, d - 4$
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$a - 4, b - 3, c - 2, d - 1$
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$a - 2, b - 3, c - 4, d - 1$
-
$a - 3, b - 4, c - 1, d - 2$
a) Palmitic acid is a saturated fatty acid. Its chemical formula is CH$ _3$(CH$ _2$)$ _{14}$COOH. Meat, cheese and diary products are the main source of the palmitic acid. It was first discovered in saponified palm oil. Excess carbohydrate in the body is converted into palmitic acid.
Commonly, candles are prepared from
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Bees wax
-
Paraffin wax
-
Stearic acid
-
Both (b) and (c)
The use of wax used to prepare candles has changed during the past few centuries. Nowadays, standard commercial candles are made from a combination of Paraffin wax and Stearic acid. A small amount of Bee wax may or may not be added in the making.
A product of glycerol and phellonic acid is
-
Wax
-
Cutin
-
Suberin
-
Sterol
Suberin is a type of lipid found in the cell wall of plants especially cork cells. It is a mixture of fatty acid material along with glycerol and phellonic acid. It gives rigidity and strength to cell wall in addition to imparting impermeability to cork cells. Waxes are esters of long chain fatty acids with cetyl or mericyl alcohol. They are found in leaf surfaces of plants, bees wax, wool fat of animal furs and ear wax. Cutin is a complex lipid formed by polymerisation of hydroxy fatty acids with or without esterification by alcohols other than glycerol. It is found in the epidermal cell walls of plants and also as a separate layer outer to epidermis. It prevents the water loss due to transpiration.
Among the following edible fishes which one is a marine fish having rich source of omega-3 fatty acids
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Mackerel
-
Mystus
-
Magur
-
Mrigala
The most widely available dietary source of omega-3 fats is oily fish, such as salmon, herring, mackerel, anchovies, menhaden, and sardines. All types of mackerel are higher-fat fish, rich in the healthful polyunsaturated fats known as long-chain omega-3s, which may help boost heart health. So, the correct answer is option A.
During symbiotic biological nitrogen fixation. The recognition of rhizobiahost interaction involves two classes of molecules there are _______________.
-
Lectins an lipids
-
Lectins and Polysaccharides
-
Flavonoids and lipids
-
Lectins and Alkaloids
The major driving force for the formation of membrane lipid bilayer
-
vander waal forces
-
electrostatic force
-
hydrophobic interactions
-
H-bond
Fats, oils, and steroids are
-
Proteins
-
Nucleic acids
-
Polysaccharides
-
Lipids
Lipids are storage compounds, triglycerides serve as reserve energy of the body. These are an important component of cell membranes structure in eukaryotic cells that helps in regulating membrane permeability. They serve as the source for fat-soluble vitamins like A, D, E, K. Example of lipids are fats, oils and steroids.
In a phospholipid bilayer, the lipid molecules are sandwiched between
-
hydrophobic heads; hydrophilic tails
-
hydrophobic tails; hydrophilic heads
-
hydrophilic heads; hydrophilic tails
-
hydrophobic tails; hydrophobic heads
So, the correct answer is 'hydrophobic tails; hydrophilic heads'.
The major site of lipid synthesis in most cells is?
-
Cytoplasmic ribosome's
-
Outer membrane of mitochondria
-
Endoplasmic reticulum
-
Golgi membranes
Choose the correct answer from the alternatives given.
Which of the following function does the lipid bilayer component of the cell membrane not provide for the cell?
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Controls the exchange of matter and chemical information between one cell and adjacent cells or the environment
-
Provides an impermeable, self-sealing membrane capable of dividing or fusing the cell without breaking
-
Provides the matrix into which proteins are inserted that facilitate the exchange of matter between the inside and outside of the cell
-
Clearly defines a boundary preventing an equilibrium between the outside and inside of the cell
The Lipid derivatives which occur in faecal material are
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Cholesterol
-
Ergesterol
-
Lanoline
-
Coprosterol
Many animals, plants and yeast synthesize sterols and their derivatives. Sterols are widely distributed in living organisms as lipid constituents. Cholesterol is a major sterol found as component of plasma membrane lipid bilayer in higher animals such as humans and other mammals. Cholesterol is metabolised to bile acids and steroid hormones. Intestinal microorganisms reduce a certain amount of cholesterol to coprosterol which is then excreted out as faeces. A form of coprosterol termed as 5-coprosterol has a low water solubility and therefore remains stable for many hundreds of years in the environment. Coprosterol is therefore, also used as an indicator of faecal pollution in water from different sources. Ergosterol is a sterol found in fungi and protozoa necessary for their survival and has functions similar to that of cholesterol. Lanolin is a lipid derivative secreted by the sebaceous glands of wool bearing animals. Lanolin is a wax, but it is not a true fat since it lacks glycerides.
So, the correct answer is option D.
This is wax.
-
Palmitic acid
-
Ethyl palmitate
-
Hexacosyl palmitate
-
Sodium stearate
Wax is a long chain of sterol ester. These are hydrophobic. They are insoluble in water but soluble in organic and nonpolar solvents. It consists of long alkyl chains. Hexacosyl palmitate is an ester derived from the palmitic acid and cetyl alcohol. It is white in color and forms an important constituent of tissues of stony corals. It is the main constituent of bee wax.
Match the column I with column II and select the correct option from the codes given below.
Sr. No | Column I | Sr.No | Column II |
---|---|---|---|
A. | Fats made of three fatty acid chain attached to glycerol | (i) | Glycogen |
B. | Glycolysis metabolic made from glycerol | (ii) | Glyceraldehyde |
C. | Storage form of glucose | (iii) | Triglycerides |
D. | the common respiratory substrate of glycolysis | (iv) | Glucose |
-
A-(iv),B(ii),C(i),D(iii)
-
A-(iii),B(ii),C(i),D(iv)
-
A-(iv),B(iii),C(i),D(ii)
-
A-(i),B(ii),C(iii),D(iv)
Column I | Column II |
---|---|
A.Fats made of three fatty acid chain attached to glycerol | iii)Triglycerides |
B. Glycolysis metabolic made from glycerol | ii) Glyceraldehyde |
C. Storage form of glucose | i) Glycogen |
D. common respiratory substrate for glycolysis | iv) glucose |
So, the correct option is 'A-(iii),B(ii),C(i),D(iv)'.
Choose the correct answer from the alternatives given.
Which of the following factors would tend to increase membrane fluidity?
-
A greater proportion of unsaturated phospholipids
-
A high membrane potential
-
A lower temperature
-
A lower cholesterol concentration in the membrane
So, the correct answer is 'A greater proportion of unsaturated phospholipids'.