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

What is the relationship of this graph?

  1. As time increases, lipid mass increases

  2. As time increases, lipid mass decreases

  3. As time decreases, lipid mass decreases

  4. As time decreases, lipid mass increases
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice biology coordination in life processes ingestion of food mechanism of digestion

What are called micelles during absorption

  1. Small glycerol molecules

  2. Small droplets of fatty acids

  3. Very small fat droplets

  4. Large fat molecules
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Micelles are small spherical aggregates formed by bile salts and fatty acids/monoglycerides, which facilitate the transport of lipids to the intestinal absorptive cells.

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The fluidity of membranes in a plant in cold weather may be maintained by?

  1. Increasing the number of phospholipids with unsaturated hydrocarbon tails

  2. Increasing the proportion of integral proteins

  3. Increasing concentration of cholesterol in membrane

  4. Increasing the number of phospholipids with saturated hydrocarbon tail
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In cold weather, membranes tend to solidify. Increasing the proportion of unsaturated phospholipids (which have kinks in their tails) prevents tight packing, thereby maintaining fluidity.

Multiple choice biology caskets of life the cell structure cytoplasm unicellular and multicellular organisms number and shape of cells

Select the correct option:

Lipids are arranged within the membrane with

  1. Polar heads toward inner side and the hydrophobic tails toward outerside

  2. Both heads and tails toward outerside

  3. Heads toward outerside and tail towards inside

  4. Both heads and tails toward innerside
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In lipid bilayer, lipids are arranged with the polar head towards the outer side and the hydrophobic/ non-polar tails towards the inner side.

Multiple choice biology meaning of life chemical organization in living beings lipids proteins and their structure

The other name of fats is

  1. Lipids

  2. Proteins

  3. Carbohydrates

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

Proteins are the polymers of amino acids held together by peptide bonds and are also called as polypeptides. Carbohydrates (sugars) are polyhydroxy aldehyde or ketones or their derivatives. Nucleic acids are polymers of nucleotides held together by phosphodiester bonds. Fats are fatty acid derivatives and are one of the storage lipids. Thus, the correct answer is A.

Multiple choice biology meaning of life chemical organization in living beings lipids proteins and their structure

Most essential fatty acid is ..........

  1. Linoleic acid

  2. Oleic acid

  3. Arachidonic acid

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The most essential fatty acids are that fatty acids that are not synthesized in our body and must come from the food we eat. For example, Linoleic acid (Omega-6 fatty acid ) is a most essential fatty acid. Linolenic acid is found in vegetable oils such as sunflower, soybean, corn, and canola oils as well as nuts and seeds.
So, the correct answer is 'Linoleic acid'.
Multiple choice biology meaning of life chemical organization in living beings lipids proteins and their structure

Lipids are insoluble in water because they are

  1. Neutral

  2. Zwitter ions

  3. Hydrophobic

  4. Hydrophilic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lipids are hydrophobic means water hating. They are water insoluble. Lipids are non-polar molecules while water is polar molecule, so there is no way for water to attach to a lipid molecule. Instead, the non-polar lipids will bind to themselves, which is why oils and fats form droplets on the surface of water.

Multiple choice biology meaning of life chemical organization in living beings lipids proteins and their structure

Membrane phospholipids are

  1. Amphipathic

  2. Amphibolic

  3. Hydrophobic

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

Membrane phospholipids are amphipathic having a polar head made of phosphate residue and a non-polar lipid tail. The polar phosphate head is exposed on the surface while non-polar lipids are embedded within the interior of membrane.

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Fat absorbed from gut is transported in blood as

  1. Micelles

  2. Liposomes

  3. Chemomicrons

  4. Chylomicrons

  5. Phagocytes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The products of lipid digestion enter the body by a different process and a different route. These products namely, long chain fatty acids, monoglycerides and diglycerides are insoluble in water and cannot be directly absorbed from intestinal contents. They combine with the bile salts and phospholipids to form small spherical water-soluble molecular aggregates called micelles. From the micelles, fatty acids, glycerides and fat-soluble vitamins are actively absorbed into the intestinal cells. In these cells, the bile salts are freed and fatty acids, glycerol, monoglycerides and diglycerides are resynthesized into fats. The fats are then mixed with cholesterol and coated with special proteins forming small globules called chylomicrons The latter are transported by exocytosis out of the epithelial cells into a lacteal.
Thus, the correct answer is option D. 
Multiple choice evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

Which of the following agent is used to detect the presence of fat in the food product?

  1. Methyl alcohol

  2. Ethyl alcohol

  3. Sodium hydroxide

  4. Iodine solution
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Shake or crush the food to make it dissolve. Filter or dilute the food and ethanol mix so that you get a clear liquid (a solution of fat in ethanol). Add this to a test tube of water. A white (milk-like) emulsion indicates the presence of fats or oils.

So, the correct option is 'Ethyl alcohol'.

Multiple choice evs food components simple test for nutrients test for nutrients protein and its function energy from different food components nutrients and foodstuffs

What compounds form fats and oils?

  1. Carboxylic acids +Alcohol

  2. Carbon Compounds +water

  3. Carbon Dioxide + Alcohol

  4. Carbon Monoxide +Alcohol
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fats and oils are esters formed by the condensation reaction between glycerol (an alcohol) and three fatty acid molecules (carboxylic acids).