Tag: lipids

Questions Related to lipids

In the fluid mosaic membrane model, the phospholipid bilayer

  1. Is sandwiched between two protein layers

  2. Is covered by a single protein layer

  3. Has proteins embedded in it

  4. Lies on top of a single protein layer


Correct Option: C
Explanation:

In the fluid mosaic model, the phospholipid bilayer has integrated as well as peripheral proteins embedded in it. The integrated proteins are found on the inside and span across the bilayer, while the peripheral proteins are found at the periphery of the lipid layers.

So the correct answer is 'has proteins embedded in it'.

Function of smooth endoplasmic reticulum is?

  1. Synthesis of lipid

  2. Synthesis of minerals

  3. Synthesis of protein

  4. None


Correct Option: A
Explanation:

Its main functions are the synthesis of lipids, steroid hormones, the detoxification of harmful metabolic byproducts and the storage and metabolism of calcium ions within the cell. The smooth ER is distinguished from the other parts of the endoplasmic reticulum by the absence of membrane-bound ribosomes.

Thus A is the correct option. 

CPPP which is the important component of sterol is mainly stood for?

  1. Cyclopentanoperhydrophenanthrene

  2. Pentanoperhydrophenanthrene

  3. Cycloperhydrophenanthrene

  4. None of the above


Correct Option: A
Explanation:

CPPP is the abbreviated form of Cyclopentanoperhydrophenanthrene. It is an important component of sterol. Thus the correct answer is option A.

Select the correct option:

Lecithin is a 

  1. Sterol

  2. Glycolipid

  3. Phospholipid

  4. Sphingolipid


Correct Option: C
Explanation:

Phospholipids are triglyceride lipids, in which one fatty acid is replaced by phosphoric acid residue often linked to additional nitrogenous group,eg., choline in lecithin.

So, the correxct answer is 'Phospholipid'.

Steroids are

  1. Tetraterpenes

  2. Polyterpenes

  3. Triterpenes and their derivative

  4. Phenolic compounds


Correct Option: C
Explanation:

Steroids are hormonal substances in animals, but they are components of membranes in most organisms. Triterpenes are precursors to steroids in both plants and animals. Steroids are derivatives of triterpenes with 26 or more carbon atoms that have undergone a characteristic type of rearrangement. So, the correct answer is option C.

Two important processes in a cell, which take place outside the membrane bound organelles, are

  1. Enzyme synthesis and DNA replication

  2. Nucleotide synthesis and mutation

  3. Fatty acid synthesis and spindle assembly

  4. Glycolysis and photophosphorylation


Correct Option: C
Explanation:
The process of fatty acid synthesis takes place in the cytoplasm and not in a membrane-bound organelle. Also, spindle assembly takes place in the centrioles which also lack a membrane.

So, the correct answer is 'fatty acid synthesis and spindle assembly'.

Cholesterol belongs to group

  1. Steroid

  2. Neutral fats

  3. Waxes

  4. Phospholipids


Correct Option: A
Explanation:
Steroids are the organic molecule which plays an important role in the growth and development of the body. The molecular structure consists of 17 carbon which are arranged in four fused structure. It is found in plants, animals and fungi. Steroids such as cholesterol forms an integral component of the cell membrane and alter the membrane fluidity. They also acts as hormone receptor for steroidal hormones. It acts as a precursor for the biosynthesis of steroid hormones, bile acid, and vitamin D. 
So, the correct answer is option A.

Lipids are insoluble in water because lipids molecules are

  1. Hydrophilic

  2. Hydrophobic

  3. Neutral

  4. Zwitter ions


Correct Option: B
Explanation:

Lipids are hydrophobic (water repelling) and non-polar. Non-polar substances, for instance fats and oils cannot be dissolved in water because they have made up of only carbon-carbon and hydrogen-carbon bonds. Only polar solutes dissolve in polar solvents.

So, the correct option is 'Hydrophobic'.

Which of these is not a lipid?

  1. Steroid

  2. Fat

  3. Polysaccharide

  4. Wax


Correct Option: C
Explanation:

The polysaccharide is a carbohydrate that is formed by the bond formation between various monomers like glucose, fructose etc. Its examples are starch, cellulose, chitin, glycogen, etc.

Hence, the correct answer is 'Polysaccharide'.

Jojoba (Simmondsia) possesses

  1. Triglyceride and wax

  2. Wax

  3. Triglyceride

  4. Sterol


Correct Option: B
Explanation:
Wax is a long chain of sterol ester. It is also used in commercial production of lubricants, rust-preventive coatings, shoe polish. Jojoba is a liquid extracted from Simmondsia chinensis of mono-esters of long-chain fatty acids and alcohols, accompanied by only a tiny fraction of triglyceride esters. It has resistance to high temperatures. It is a fungicide. It  can be used for controlling mildew.
So, the correct answer is option B.