Tag: derived lipids

Questions Related to derived lipids

Which one of the following is not correctly matched?

  1. Cutin- Consists of long chain fatty acids and polyhydroxy derivatives of these fatty acids

  2. Pectin-Methylated polymer of flacturonic acid

  3. Lignin- Formed by condensation on coniferyl alcohol

  4. Callose- Glycosylated aliphatic acid


Correct Option: A

Which one of the following is not a correct statement regarding the design of biological membranes?

  1. Carbohydrate molecules associated with membranes tend to be associated with protein molecules embedded in the membrane

  2. Hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are exposed directly to the extracellular environment

  3. Cholesterol is a type of lipid frequently found in membranes of animal cells

  4. Protein molecules can be located on the inner and outer surfaces of the membrane as well as traverse the entire thickness of the bilayer


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 extracellular environment.

So, the correct answer is 'Hydrophobic ends of phospholipid molecules in the outer monolayer of the membrane are exposed directly to the extracellular environment'.

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'.