Tag: biological molecule

Questions Related to biological molecule

Name the chemical formula.
C$ _{16}$H$ _{32}$O$ _2$

  1. Palmitic acid

  2. Stearic acid

  3. Glycerol

  4. Galactose


Correct Option: A
Explanation:

Palmitic acid or hexadecanoic acid was discovered by Edmond Fremy. It is commonly found in plants, animals and microorganisms.Its chemical formula is CH$ _3$(CH$ _2$)$ _{14}$COOH.It is a saturated fatty acid.

Which of the following is not an essential unsaturated fatty acid


  1. Oleic acid

  2. Linoleic acid

  3. Linolenic acid

  4. Stearic acid


Correct Option: D

What is a cholesterol?

  1. Phospholipid

  2. Wax

  3. Steroid

  4. Triglyceride


Correct Option: C
Explanation:

Steroids are crystallisable lipids having four hydrocarbon rings consisting of three cyclohexane and one cyclopentane ring and a long hydrocarbon side chain. Fatty acids are absent. In animals, sterols are precursors of steroid hormones and vitamin D. Cholesterol is a sterol of animal systems which forms bile salts, is a component of plasma membrane and hormones.

Essential fatty acids were discovered by

  1. Evans and Burr

  2. Bloor

  3. Sutherland

  4. Beevers


Correct Option: A
Explanation:

Essential fatty acids are those fatty acid which plays 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. It was discovered by Evans and Burr.

So, the correct answer is option A.

Lanolin or wool fat is a

  1. Hard fat

  2. Oil

  3. Wax

  4. Sterol


Correct Option: C
Explanation:

Lanolin is also known as wool fat, wool grease or wool wax. It is secreted by the sebaceous glands of wool-bearing animals. It is obtained by the sheep which has been raised specifically for wool. It helps the sheep to shedd water from their coats and protect them from changing environmental conditions. Wax is a long chain of sterol ester. It is also used in commercial production of lubricants, rust-preventive coatings, shoe polish.

So, the correct answer is option C.

Linoleic is unsaturated fatty acid whose content is highest in

  1. Cotton oil

  2. Sunflower oil

  3. Coconut oil

  4. Groundnut oil


Correct Option: B
Explanation:

Unsaturated fats are liquid at room temperature as they have double bonds. The essential fatty acids like alpha-linolenic acid and linoleic acid are unsaturated as they have double bonds. Sunflower oil is a non- volatile oil. It is a mixture of mostly oleic acid (omega-9)-linoleic acid (omega-6). The composition precisely comprises of  59% linoleic acid, oleic acid 30%, stearic acid 6%, and palmitic acid is 5%.

So, the correct answer is option B.

Match the columns:

$a$ Biological pigments $1.$ Sodium chloride
$b$ Chemical messengers $2.$ Steroids
$c$ Important constituent of blood $3.$ Prostaglandins
$d$ Four carbon rings $4.$ Terpenes
  1. $a - 2, b - 4, c - 3, d - 1$

  2. $a - 2, b - 1, c - 4, d - 3$

  3. $a - 3, b - 4, c - 2, d - 1$

  4. $a - 4, b - 3, c - 1, d - 2$

  5. $a - 3, b - 4, c - 1, d - 2$


Correct Option: D

Arachidonic acid gives rise to

  1. Terpenes

  2. Prostaglandins

  3. Gangliosides

  4. Cerebrosides


Correct Option: B
Explanation:
Arachidonic acid is a polyunsaturated omega-6 fatty acid. It is present in the phospholipids and helps in the formation of membranes. It is not considered as essential fatty acid as it can be easily formed by the conversion of linoleic acid to arachidonic acid. It is the most abundant fatty acid in the brain. It helps in the synthesis of prostaglandins. The prostaglandins synthesized is PG$ _2$. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. 
So, the correct answer is option D.

A saturated fatty acid is

  1. Arachidonic acid

  2. Stearic acid

  3. Oleic acid

  4. Linoleic acid


Correct Option: B
Explanation:

Saturated fatty acids have single bond and are solid at room temperature. Hydrogenation is the process which involves the addition of hydrogen in the presence of nickel, palladium or platinum. On addition of hydrogen, the double bonds of unsaturated fatty acids are reduced to saturated fatty acid. Stearic acid is a saturated fatty acid as it has single carbon bonds. It has eighteen carbon with chemical formula of  C$ _{18}$H$ _{36}$O$ _2$. It can be produced by saponification of the triglycerides.

So, the correct answer is option B.

Which one is essential fatty acid?

  1. Linoleic acid

  2. Linolenic acid

  3. Arachidonic acid

  4. All the above


Correct Option: D
Explanation:
Essential fatty acids are that fatty acid which plays 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.  are the two essential fatty acid. Alpha-linolenic acid and linoleic acid are the two essential fatty acid. Arachidonic acid is a polyunsaturated omega-6 fatty acid. It is present in the phospholipids and helps in the formation of membranes. It is not an essential amino acid as it can be easily formed by the conversion of linoleic acid to arachidonic acid. It is the most abundant fatty acid in the brain. It becomes essential if there is a deficiency of linoleic acid.
So, the correct answer is option D.