Tag: bio-chemistry

Questions Related to bio-chemistry

Stability of the plasma membrane is enhanced by _________ .

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. cholesterol molecules

  2. phospholipids

  3. glycoproteins

  4. glycolipids

Show answer
Correct Option: A
Explanation:

Cholesterol helps to keep the membrane stable. This stability is maintained  as: At high temperatures, cholesterol reduces membrane fluidity by restraining the movement of phospholipids. At low temperatures, cholesterol gives solidification of the membrane because it prevents the close packing of phospholipids.

So, the correct answer is 'cholesterol molecules'

Heterotrophs can metabolize lipids by a process called ___________ into monomers of _____________ and fatty acids.

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Hydrolysis; Glycerol

  2. Dehydration synthesis; Glycerol

  3. Hydrolysis; Glycolipids

  4. Dehydration synthesis; Glycolipids

Show answer
Correct Option: A
Explanation:

Heterotrophs can metabolize lipids by a process of hydrolysis, where water molecule is added to break down a chemical compound (lipids). 

Lipids on hydrolysis yield fatty acids and glycerol
So, the correct answer is 'Hydrolysis; Glycerol'

Cholesterol content is minimum in

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Fish

  2. Cow's skimmed milk

  3. Liver

  4. Vegetable oils

Show answer
Correct Option: D
Explanation:

Cholesterol content is minimum in vegetable oils as plant have ergosterol as the major sterol present in them. Cholesterol is present in animals and 20 % of total cholesterol is sythesised in liver.

Animal membranes contain

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Steroids

  2. Chlorophyll

  3. Prostaglandins

  4. Vitamin A

Show answer
Correct Option: A
Explanation:
Steroids are the organic molecule which plays an important role in the growth and development of the body. It is a four-ring structure. Steroids such as cholesterol form an integral component of the cell membrane and alter the membrane fluidity. It provides the stability to the cell membrane by limiting the membrane fluidity. 
So, the correct answer is option A.

Saturated fatty acid that reduces oil quality is

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Palmitic acid

  2. Stearic acid

  3. Erucic acid

  4. All the above.

Show answer
Correct Option: C
Explanation:

Fatty Acid Composition of Canola Oil The decrease in the level of erucic acid in rapeseed oil resulted in a marked increase in C18 acids, which make up approximately 95% of all fatty acids present in canola oil. 

Hence C is the correct answer. 

 .......... is the regulatory enzyme in the fatty acid biosynthesis.

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Aminoacyl synthetase

  2. Acetyl CoA carboxylase

  3. Peptidyl transferase

  4. None of the above

Show answer
Correct Option: B
Explanation:
Fatty acids are components of the phospholipids that make up the bulk of the lipid bilayers of all cellular membranes. It is synthesized by cytosolic acetyl-CoA  through carboxylation by acetyl-CoA carboxylase into malonyl CoA. This conversion occurs primarily in the liver, adipose tissue and lactating mammary glands, where the fatty acids are combined with glycerol to form triglycerides
So, the correct answer is option B.

The molting hormone ecdysone belongs to the category of

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Amines

  2. Long chain peptides

  3. Steroids

  4. Fatty acids

Show answer
Correct Option: C
Explanation:
Ecdysone is a steroidal prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands.

So, the correct answer is 'C'.

Consider the following fatty acids.
a. Stearic acid
b. Oleic acid
c. Linoleic acid
d. Linolenic acid
Which of these are found in plants?

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. $1$ and $2$

  2. $1, 3$ and $4$

  3. $2, 3$ and $4$

  4. $1, 2, 3$ and $4$

Show answer
Correct Option: A

The plastids which are filled with a large amount of lipids are called.

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Etiolates

  2. Elastoplasts

  3. Leucoplasts

  4. Amyloplasts

Show answer
Correct Option: A

The oil of which one of the following plants is edible and rich in poly unsaturated fatty acids?

bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

  1. Aleurites fordii

  2. Cocos nucifera

  3. Carthamus tinctorius

  4. Ricinus communis

Show answer
Correct Option: A