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

The absorbed fatty acids are used in synthesizing fat in which of the following cells?

  1. Liver cells

  2. Intestinal cells

  3. Cardiac cells

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The absorbed fatty acids are used in synthesizing fat in the intestinal cells. They are primarily stored as fat in the adipose cells. They have an important role in providing energy to the body in fasting.
So the correct answer 'Intestinal cells'.
Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Which of the following statements are incorrect about chylomicrons?


(i) Chylomicrons are produced in the epithelial cells of the small intestine.
(ii) It contains triglycerides, cholesterol, and phospholipids.
(iii) They are protein-coated small vesicles.
(iv) Chylomicrons are released from the epithelial cell into lacteals.

  1. (i) and (iv)

  2. (ii) and (iii)

  3. (i), (ii), (iii) and (iv)

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All statements provided are correct descriptions of chylomicrons: they are formed in intestinal epithelial cells, contain lipids, are protein-coated, and enter lacteals.

Multiple choice different stages of growth reproductive system in humans division for growth and reproduction human system biology

............... is the pigment which is mainly released due to degradation of phospholipids in the cell membrane and actively participates in the ageing.

  1. Lipofuchsin

  2. Free radical

  3. Cellular proteins

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Ageing is a complex process that varies as to how it affects different people and even different organs. Most gerontologists (people who study aging) feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors.
  • Lipofuscin (age pigment) is a brown-yellow, electron-dense, autofluorescent material that accumulates progressively over time in lysosomes of postmitotic cells, such as neurons and cardiac myocytes. It participates in the ageing phenomenon.
  • Hence Lipofuchsin is the pigment which is mainly released due to degradation of phospholipids in the cell membrane and actively participates in the ageing.
  • So, the correct answer is 'Lipofuchsin'.
Multiple choice different stages of growth reproductive system in humans division for growth and reproduction human system biology

Lipofuscin causes ageing by

  1. Degradation of cellular protein

  2. Degradation of phospholipid of plasma membrane

  3. Degradation of endoplasmic reticulum

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Ageing is a complex process that varies as to how it affects different people and even different organs. Most gerontologists (people who study aging) feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors.
  • Lipofuscin (age pigment) is a brown-yellow, electron-dense, autofluorescent material that accumulates progressively over time in lysosomes of postmitotic cells, such as neurons and cardiac myocytes. It causes ageing by the degradation of phospholipid of the plasma membrane.
  • So, the correct answer is 'degradation of phospholipid of plasma membrane'.
Multiple choice botany economic importance of bacteria and fungi fungi: benefits and harmful effects useful and harmful fungi uses of fungi

Lipid dissolving enzymes are obtained from

  1. Trichoderma

  2. Streptococcus

  3. Candida

  4. Mucor
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Candida is the fungus that causes infection on the skin or the mucous membrane.
  • The cells of the fungus in order to infect the host cell needs to break the cell membrane and enter the cell. For this purpose the fungi secrets phospholipase and lipase to dissolve the cell membrane which is made us of the lipid bilayer with units of phospholipid present in it.
  • After entering the cell the fungi starts growing on the cell in a parasitic way. The secretions which are released by the fungus cause itching and rashes on the area of infection.
  • Whereas Trichoderma is not an infectious agent but it lives in a symbiotic relationship with many plants. Some species of Trichoderma maybe pathogenic but only to plants.
  • Streptococcus is a disease-causing organism but it causing the disease using the process of hemolytic where it mainly attacks the blood cells and causing their lysis.
  • Mucor is fungus whose growth is seen on the stale bread. It is black colour mold growing on the bread.
  • Therefore the answer Option C is correct as Candida is the only one among the options that secrets lipid dissolving enzymes.
Multiple choice biology cell and cell organelles cell membrane and cell wall cell wall cell division in embryo development

During breakdown of lecithin which of the following is not obtained?

  1. Trihydroxy propane

  2. Fatty acid

  3. Choline

  4. Sphingosine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Lecithin is also known as phosphatidylcholine (a group of phospholipids) which are important for maintaining the cell structure and metabolism.
  • Lecithins are composed of phosphoric acid, choline, esters of glycerol and two fatty acids. 
  • Thus, during the breakdown of lecithin fatty acid, choline and sphingosine are obtained.
  • So the correct answer is 'Trihydroxy propane'.