Tag: biological molecule

Questions Related to biological molecule

Content of unsaturated fatty acid linolenic acid is highest in

  1. Sunflower oil

  2. Cotton seed oil

  3. Groundnut oil

  4. Coconut oil


Correct Option: A
Explanation:

Unsaturated fatty acid is those which contain one or more double bond in their fatty acids. Generally, it is found in plants fats. It also lowers blood cholesterol. Linoleic is unsaturated fatty acid containing two double bonds. Sunflower oil contains highest linoleic acid. Thus, the correct answer is A.

Unsaturated fatty acids have

  1. No double bonds

  2. High melting point

  3. One or more double bonds

  4. Disulphide bonds


Correct Option: C
Explanation:
Fats or fatty acid which has at least one double bond in the chain is called as an unsaturated fatty acid. They are liquid at room temperature as they have double bonds. With the increase in the double bond, the intermolecular interaction gets weak and the melting point decreases.
So, the correct answer is option C.

Number of fatty acid residues present in one molecule of fat is

  1. $4$

  2. $3$

  3. $2$

  4. $1$


Correct Option: B
Explanation:

Fat is stored reserve for the body which provides energy. These are triesters of glycerol. It is obtained from fatty acids and glycerol. It consists of one glycerol molecule and three fatty acid molecules. The carboxyl end of the fatty acid combines with the three -OH groups of the glycerol to form the ester. So, the correct answer is option B.

A fatty acid not synthesised in human body is

  1. Cholesterol

  2. Linoleic acid

  3. Glycerol

  4. None of the above


Correct Option: B
Explanation:
Essential fatty acids are that fatty acids which play an important role in the biological process and they can be metabolized easily. These acts as a fuel rather getting deposited as fat in the body. The human body cannot synthesize essential fatty acids. Alpha-linolenic acid and linoleic acid are the two essential fatty acid. Unsaturated fats are liquid at room temperature as they have double bonds. Saturated fatty acids have the single bond and are solid at room temperature. 
So, the correct answer is option B.

The most essential of the fatty acids is

  1. Arachidonic acid

  2. Palmitic acid

  3. Linoleic acid

  4. Oleic acid


Correct Option: C
Explanation:

Fatty acids are of two types, the saturated fatty acids that have single bond across the carbon chain and the unsaturated fatty acids that have one or more double bond across the carbon chain. When there are more than one double bonds, they are called the polyunsaturated fatty acids. These are called the essential fatty acids as they cannot be synthesized in the body and must be supplied through the external source. Linoleic acid and linolenic acid are the essential fatty acids.

A. Arachidonic acid is also a polyunsaturated acid but it can be synthesized through the linoleic acid in the human body.
B. Palmitic acid is saturated fatty acid found in waxes and palm oil.
C. Linoleic is an essential fatty acid.
D. Oleic acid is saturated fatty acid found in vegetables and animal fats.
Hence, the correct answer is 'Linoleic acid'

Which alcohol is present in fats?

  1. Glycerol

  2. Butanol

  3. Ethanol

  4. Octanol


Correct Option: A
Explanation:
Butanol can be used as a biofuel. Molecular formula is C$ _4$H$ _{10}$O.
Ethanol is used for drinking. Molecular formula is C$ _2$H$ _6$O.
Octanol is used in perfumes and flavorings. The molecular formula is C$ _8$H$ _{18}$O.
Fat is stored reserve for the body which provides energy. These are triesters of glycerol. Glycerol has the chemical formula of  C$ _3$H$ _8$O$ _3$. It consists of one glycerol molecule and three fatty acid molecules. The carboxyl end of the fatty acid combines with the three -OH groups of the glycerol to form the ester. 
So, the correct answer is option A.

Hydrolysis of lipids produces

  1. Glycerine and glycerol

  2. Fatty acids and trihydric alcohol

  3. Glycine

  4. All the above


Correct Option: B

Unsaturated fatty acids have

  1. Palmitic acid

  2. Stearic acid

  3. Oleic acid

  4. One or more double bonds


Correct Option: D
Explanation:

An unsaturated fat is a fat or fatty acid in which there is one or more double bond in the fatty acid chain. A fat molecule is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. Where double bonds are formed, hydrogen atoms are eliminated.

An essential fatty acid is

  1. Palmitic acid

  2. Arachidonic acid

  3. Stearic acid

  4. Arachidic acid


Correct Option: B
Explanation:

Arachidonic acid is not one of the essential fatty acids. Rather it is conditionally essential fatty acid which, becomes essential if its precursor, linoleic acid is deficient thereby resulting in the inability to convert linoleic acid to arachidonic acid. However, some mammals lack the ability or have a very limited capacity to convert linoleic acid to arachidonic acid, making it an essential part of their diets. So, the correct answer is 'Arachidonic acid'.

Higher animals cannot synthesise a few essential fatty acids; these are typically

  1. Saturated

  2. Branched

  3. Unsaturated

  4. Cyclic


Correct Option: C
Explanation:
Unsaturated fats are liquid at room temperature as they have double bonds. Those unsaturated fatty acid which are not synthesized by the body are essential amino acid. Higher animals cannot synthesize a few essential fatty acids which are typically unsaturated because they lack desaturases that introduce double bonds beyond the ninth carbon atom. 
So, the correct answer is option C.