Biology · Chemistry

Lipids, Fats, and Biochemistry

1,130 Questions

Lipids, fats, and biochemistry explore the structure and function of biological molecules. This includes fatty acids, cholesterol, trans-fats, and cellular membranes. Questions on this topic frequently appear in science sections of competitive government exams.

Types of fats and lipidsCholesterol and human bodyFatty acidsCellular membranes

Lipids, Fats, and Biochemistry Questions

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

Animal membranes contain

  1. Steroids

  2. Chlorophyll

  3. Prostaglandins

  4. Vitamin A
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Saturated fatty acid that reduces oil quality is

  1. Palmitic acid

  2. Stearic acid

  3. Erucic acid

  4. All the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
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. 

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

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

  1. Aminoacyl synthetase

  2. Acetyl CoA carboxylase

  3. Peptidyl transferase

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
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.
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Cholesterol belongs to which of the following groups

  1. Steroids

  2. Neutral fats

  3. Waxes

  4. Phospholipids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The steroids are composed of seventeen carbon atoms, bonded in four fused rings: three six-membered cyclohexane rings and one five-membered cyclopentane ring. The steroids differ in the functional group attached to this four-ring core and by the oxidation state of the ring.

Steroids such as cholestrol decrease membrane fluidity. Like lipids, these are highly concentrated energy stores. They are normally metabolized and excreted.
So, the correct option is 'Steroids'.

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

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

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

  1. Cyclopentanoperhydrophenanthrene

  2. Pentanoperhydrophenanthrene

  3. Cycloperhydrophenanthrene

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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

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

Steroids are

  1. Tetraterpenes

  2. Polyterpenes

  3. Triterpenes and their derivative

  4. Phenolic compounds
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice evs food components energy from different food components nutritional requirements of the body need for nutrients simple test for nutrients test for nutrients

During prolonged fasting, the sequence of organic compounds used by body is

  1. Carbohydrates, fats, proteins

  2. Fats, carbohydrates, proteins

  3. Carbohydrates, proteins, lipids

  4. Proteins, lipids, carbohydrates
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During fasting, the body first utilizes glycogen (carbohydrates) for energy, followed by stored fats (lipids), and finally breaks down proteins (muscle tissue) as a last resort.

Multiple choice biology health and hygiene - food for living energy from different food components nutritional requirements of the body need for nutrients

Which is useful in human beings?

  1. Cholesterol

  2. Animal fat

  3. High density lipoprotein cholesterol

  4. Low density lipoprotein cholesterol
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Molecules called lipoproteins to carry cholesterol in the blood. Two important kinds of lipoproteins are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL cholesterol is often referred to as "bad cholesterol" because too much is unhealthy. HDL is often referred to as “good cholesterol” because it is protective.

So, the correct answer is 'High-density lipoprotein cholesterol'.