Tag: bio-chemistry

Questions Related to bio-chemistry

$^{18}$C unsaturated fatty acid with three double bonds is 

  1. Oleic aicd

  2. Linoleic acid

  3. Linolenic acid

  4. Arachidonic acid


Correct Option: B
Explanation:

Linolenic acid 18 carbon containing unsaturated fatty acid with three double bonds. It is found in plants and required in the formation of prostaglandin.

So, the correct answer is 'Linoleic acid'.

Identify the incorrectly matched pair.

  1. Ferritin - storage protein

  2. Stearic acid - unsaturated fatty acid

  3. Tyrosine - aromatic amino acid

  4. Vinblastin - alkaloid


Correct Option: B
Explanation:

Fatty acids are of two types based on the single and double bonds in their hydrocarbon chain. The saturated fatty acids have only single bonds in their hydrocarbon chain. These are mostly obtained from an animal source. They exist as solids at room temperature. The unsaturated fatty acids have both the single and double bonds in their hydrocarbon chain. These are mostly derived from plant sources. They exist as a liquid at room temperature.

A. Ferritin is iron-storing protein.
B. Stearic acid is a saturated fatty acid made up of 18-carbons.
C. Tyrosine is an aromatic amino acid with a benzene ring.
D. Vinblastin is a vinca alkaloid obtained from the plant Vinca rosea.
Hence, the correct answer is 'Stearic acid- unsaturated fatty acid'

Omega 3 fatty acid is present in 

  1. Sun flower oil

  2. Flax seed oil

  3. Ground nut oil

  4. Butter


Correct Option: B
Explanation:

Flaxseed oil contains alpha-linolenic acid (ALA), a form of omega-3 fatty acid that is only converted in small amounts to active forms of omega-3, like EPA and DHA. It is high in Omega-3 Fatty Acids.

Thus B is the correct answer. 

Polyunsaturated fatty acid is

  1. Arachdionic

  2. Palmitic

  3. Stearic

  4. None of the above


Correct Option: A
Explanation:

Fatty acids with no carbon-carbon double bonds are said to be saturated those with at least one double bonds are unsaturated. Unsaturated fatty acids with more than one carbon-carbon double bond are referred to as polyunsaturated. Two essential polyunsaturated fatty acids are linoleic acid made up of 18 carbon atoms and having 2 double bonds and linolenic acid made up of 18 carbon atoms and having three double bonds. They cannot be synthesized by mammals and must be supplied in their diet. Arachidonic acid is made up of 20 carbon atoms and has four double bonds.

Sporopollenin is chemically a

  1. Homoplysaccharide

  2. Fatty substance

  3. Protein

  4. Heteropolysaccharide


Correct Option: B
Explanation:

The wall of the mature pollen grain is stratified. It comprises two principal layers the internal layer is called as intine and the outer layer is called as exine. The intine is pecto-cellulosic in nature. The exine is chiefly composed of a class of material called as sporopollenin. Chemical analysis has revealed that it is a mixture of biopolymers, containing long chain fatty acids, phenylpropanoids, phenolic compounds and carotenoids. It is derived from carotenoids by oxidative polymerization. Sporopollenin is resistant to physical and biological decomposition. Because of this property, the pollen grain walls are often preserved for long periods in fossil deposits.

Long chain molecules of fatty acids are formed by

  1. Polymerisation of 2 carbon compounds.

  2. Decomposition of fats.

  3. Polymerisation of glycogen.

  4. Conversion of glycogen.


Correct Option: A
Explanation:

Long chain molecules of fatty acids are formed by polymerisation of 2 carbon compounds. A fatty acid is a carboxylic acid with a long aliphatic tail (chain), which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids that have carbon-carbon double or triple bonds are known as unsaturated. Fatty acids without double bonds are known as saturated. They differ in length as well. Long-chain fatty acids (LCFA) are fatty acids with aliphatic tails 13 to 21 carbons.

Which among the following is a main component of plant cuticle and a fatty acid polyester?

  1. Agar

  2. Lignin

  3. Suberin

  4. Cutin


Correct Option: D
Explanation:

Cutin is a polymer which is the main component of the plant cuticle, which covers all aerial surfaces of plants. Cutin consists of $\omega$-hydroxy acids and their derivatives, which are interlinked via ester bonds, forming a polyester polymer of indeterminate size. There are two major monomer families of cutin, the C16 and C18 families. The C16 family consists mainly of 16-hydroxy palmitic acid and 9,16- or 10,16-di hydroxy palmitic acid. The C18 family consists mainly of 18-hydroxy oleic acid, 9,10-epoxy-18-hydroxy stearic acid, and 9,10,18-trihydroxystearate.

Essential fatty acids are

  1. Arachidonic acid

  2. Linolenic

  3. Linoleic acid

  4. All of the above


Correct Option: D
Explanation:
  • Animals that cannot synthesize fatty acids in the body de novo are called as an essential fatty acid. These (arachidonic acid, linolenic, linoleic acid) are polyunsaturated fatty acids essential for growth and health but are not synthesized in the animal body. 
  • Linoleic acid is abundant in corn, peanut, cottonseed and soyabean oil and gives rise to other two in the body.
  • The deficiency of these fatty acids causes sterility, kidney failure, and skin lesions.

Neutral fat are

  1. Glycerol

  2. Fatty acids

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

Triglycerides or neutral fats or true fats are the esters of three molecules of fatty acids and one molecule of trihydric alcohol glycerol. Hence, they are also called triglycerides. Oils are liquid at room temperature. They possess either small or unsaturated fatty acid.

What are glycerides of fatty acids?

  1. Lecithin

  2. Phospholipids of plasma membrane

  3. Vegetable oils

  4. All of the above


Correct Option: D
Explanation:
Glyceride denotes a fatty ester of glycerol. The term is usually used in combination with phospho- (phosphoglyceride). The use of mono-, di-, and triglyceride is being replaced by the more precise terms mono-, di-, and triacylglycerol, respectively. 
Lecithin is any of a group of phospholipids that on hydrolysis yield two fatty acid  molecules and a molecule each of glycero-phosphoric  acid and choline. They are found in nervous tissue, especially myelin sheaths and egg yolk, and in the plasma membrane of plant and animal cells.
Vegetable oils are the oils and fats obtained from plants.