Tag: lipids

Questions Related to lipids

Which one is a lipid?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Stachyose

  2. Lycopene

  3. Leucine

  4. None of the above

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Correct Option: D
Explanation:

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 $C _{24}H _{42}O _{21}$

Lycopene is a naturally occurring carotenoid pigment which gives fruits and vegetables its red colour. It is found in watermelon, tomato and red carrots. It protects lipids, proteins and DNA against oxidative damage. It is a powerful antioxidant which protects the body from damage against various diseases.
Leucine is an amino acid which stimulates muscle protein synthesis and also prevents the deterioration of muscles with proteins. It is found in cheese, soyabean, beef, pork, nuts, seeds, fish etc.
Thus, the correct answer is option D. 

Lipids are classified into $3$ main types, which includes

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Simple lipids

  2. Compound lipids

  3. Derived lipids

  4. All of them

Show answer
Correct Option: D
Explanation:

Lipids are classified into simple, compound and derived lipids. 

  1. Simple lipids are esters of fatty acids with various types of alcohols.
  2. Compound lipids are esters of fatty acids with various types of alcohols in addition to a prosthetic group.
  3. Derived lipids are those produced by the hydrolysis of the first two groups.
So the correct option is 'All of them'

Choose the odd one out w.r.t. polymer _____________.

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Proteins

  2. Lipids

  3. Polysaccharides

  4. Nucleic acids

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Correct Option: B
Explanation:

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. 

So, the correct answer is, 'Lipids'.

Choose the correct answer from the alternatives given.
In a phospholipid bilayer, the

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Phosphate groups are hydrophobic

  2. Fatty acid tails are hydrophilic

  3. Proteins are located only between the two layers

  4. Phosphate heads are oriented towards the exterior of the cell or toward the cytoplasm

Show answer
Correct Option: D
Explanation:
In the fluid mosaic model, the phospholipid bilayer has integrated as well as peripheral proteins embedded in it. This bilayer is composed of hydrophilic phosphate heads and hydrophobic tails. The phosphate heads are oriented towards the exterior or towards 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

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. At the surfaces of the membrane

  2. In the interior of the membrane

  3. Spanning the membrane

  4. Both (a) and (b)

Show answer
Correct Option: B
Explanation:
In a cell membrane, the hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are sandwiched between the hydrophilic heads of the phospholipid bilayer and are not exposed to the environment.

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.

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. A, D & E

  2. B, C & D

  3. A, C & E

  4. A, B, C & F

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Correct Option: A

The properties of lipids are

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Insoluble in water and soluble in fat solvents.

  2. High energy content.

  3. Structural component of cell membrane.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

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?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Three fatty acids with one glycerol molecule

  2. Three fatty acids with two glycerol molecules

  3. Two fatty acids with two glycerol molecules

  4. One fatty acids with one glycerol molecule

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Correct Option: A

The maximum number of double bonds present in essential fatty acids is 

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: D
Explanation:

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?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Composed of fatty acids

  2. Triglycerides

  3. Insoluble in water

  4. All of the above

Show answer
Correct Option: D
Explanation:

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.