Biology · Chemistry

Lipids, Fats, and Biochemistry

1,009 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 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.

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

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).

Multiple choice chemistry chemical reactions of organic compounds alkanoic acids nomenclature of carboxyl group nomenclature of carboxylic acids

$C _nH _{2n-1}COOH$ is the general formula for:

  1. saturated fatty acids

  2. unsaturated fatty acids

  3. simple lipids

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

$C _nH _{2n-1}COOH$ is a general formula for unsaturated fatty acids.

For example: $CH _2=CH-COOH$
Propenoic acid $C _2H _3COOH$
$C _nH _{2n+1}COOH$ is general formula for saturated fatty acids.
For example: $CH _3COOH$ is Ethanoic acid.

Multiple choice biology diet, drugs and disease effect on general health growth and development in young people nutrient deficiency diseases diseases caused by changes in lifestyle nourishment and malnutrition

Obesity is due to extra consumption of

  1. Carbohydrates

  2. Fats

  3. Proteins

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Obesity results from the excess consumption of energy-dense foods, specifically carbohydrates and fats, which the body stores as adipose tissue when not utilized.

Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

Which one of the following will be largely different in various animal species?

  1. Carbohydrates

  2. Fats

  3. Proteins

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

Proteins are the polymers of amino acids linked with peptide bonds and perform various functions like carrier, enzyme or hormone. It is considered the most diverse molecule and differs from animal to animal. The diversity in proteins occurs due to the R group present which changes with the change in the amino acid.

Hence, the correct answer is 'Proteins'.

Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

Which ones are not true?
(a) Glycerol is a 3-carbon alcohol with 3-$OH$ groups as binding sites
(b) Waxes are esters of long chain alcohol and saturated fatty acids
(c) The term protein was coined by Mulder
(d) Agar is an indispensable polysaccharide being a complex polymer of glucose and sulphur containing carbohydrates

  1. a and c only

  2. d only

  3. a and d only

  4. a, b and d only
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

a) Glycerol has chemical formula of  C$ _3$H$ _8$O$ _3$. 3 OH groups act as binding site. The carboxyl end of the fatty acid combines with the three -OH groups of the glycerol to form ester. The statement is true.

b) Wax is a long chain of esters of alcohol and saturated fatty acids. These are hydrophobic. It consists of long alkyl chains. The statement is true.
c)  The term protein was coined by Mulder in 1838. Proteins are building blocks of the body. The proteins are made up of amino acids. The amino acids are linked together by peptide bonds to form a protein. Peptide bond is formed by the linkage of the carboxyl group of one amino acids with the amino group of the amino acids. The statement is true.
d) Agar is a jelly like substance which is mainly derived from agarose present in the cell wall of the algae. The statement is false as it is not a polymer of glucose and sulphur but it is a linear polymer of galactose.
So, the correct answer is option B.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Which of the following is TRUE regarding micelles in the intestine?

  1. Micelles are very small fat molecules

  2. Micelles are small spherical water soluble droplets

  3. Micelles help fatty acids and glycerol to be absorbed in to the lymph vessels

  4. Micelles are also called chylomicrons
Reveal answer Fill a bubble to check yourself
B,C Correct answer
Explanation

Micelles are formed when bile emulsifies the fat which makes it water soluble and can be absorbed by the intestinal wall, later on, they convert into chylomicrons by coating them with proteins are absorbed by the lymph vessels which transport it into a blood and then it reaches the cell.

So the correct option is 'Micelles are small spherical water-soluble droplets and Micelles help fatty acids and glycerol to be absorbed into the lymph vessels'.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Chylomicrons are protein coated small fat globules formed in

  1. Lumen of intestine

  2. Lacteals of villi

  3. Cells of mucosa

  4. Blood vessels of villi
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Chylomicrons are protein coated small fat globules formed in lumen of the small intestine, it is in this form that the fats are absorbed across the intestinal lumen into the circulatory system
So, the correct answer is 'Lumen of intestine'
Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Fatty acids and glycerol are first absorbed by

  1. Lymph vessels

  2. Blood

  3. Blood capillaries

  4. Hepatic portal vein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Triglycerides are emulsified by bile and hydrolyzed by the enzyme lipase, resulting in a mixture of fatty acids and monoglycerides. These then pass from the intestinal lumen into the enterocyte, where they are re-esterified to form triacylglycerol. The triacylglycerol is then combined with phospholipids, cholesterol ester, and apolipoprotein to form chylomicrons. These chylomicrons then pass into the lacteals, forming a milky substance known as chyle. The lacteals merge to form larger lymphatic vessels that transport the chyle to the thoracic duct where it is emptied into the bloodstream at the subclavian vein.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Fatty acids are primarily absorbed through blood capillaries, has which of the following number of carbon molecules?

  1. Up to 10 carbons

  2. More than 10 carbons

  3. Up to 20 carbons

  4. More than 20 carbons
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Fatty acids with two to six carbon atoms are called short-chain fatty acids or volatile fatty acids. They are primarily absorbed through blood capillaries. 
So the correct answer is 'Up to 10 carbons'.