Tag: lipids
Questions Related to lipids
A product of glycerol and phellonic acid is
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Wax
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Cutin
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Suberin
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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
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Mystus
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Magur
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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 _______________.
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Lectins an lipids
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Lectins and Polysaccharides
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Flavonoids and lipids
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Lectins and Alkaloids
The major driving force for the formation of membrane lipid bilayer
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vander waal forces
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electrostatic force
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hydrophobic interactions
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H-bond
Fats, oils, and steroids are
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Proteins
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Nucleic acids
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Polysaccharides
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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
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hydrophobic heads; hydrophilic tails
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hydrophobic tails; hydrophilic heads
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hydrophilic heads; hydrophilic tails
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hydrophobic tails; hydrophobic heads
So, the correct answer is 'hydrophobic tails; hydrophilic heads'.
The major site of lipid synthesis in most cells is?
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Cytoplasmic ribosome's
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Outer membrane of mitochondria
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Endoplasmic reticulum
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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
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Provides an impermeable, self-sealing membrane capable of dividing or fusing the cell without breaking
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Provides the matrix into which proteins are inserted that facilitate the exchange of matter between the inside and outside of the cell
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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
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Ergesterol
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Lanoline
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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.
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Palmitic acid
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Ethyl palmitate
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Hexacosyl palmitate
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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.