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 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'.
Multiple choice biology cell and cell organelles cell membrane and cell wall cell wall cell division in embryo development

Which of the following statement is INCORRECT regarding biological membrane?

  1. It is composed of lipids and proteins

  2. Peripheral proteins are loosely associated with the membrane

  3. Integral proteins span the lipid bilayer

  4. Lipids and membrane proteins do not provide structural and functional asymmetry
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Biological membranes are highly asymmetric in both lipid composition and protein distribution, which is essential for their functional diversity.

Multiple choice biology cell and cell organelles cell membrane and cell wall cell wall cell division in embryo development

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.
Therefore the correct option is C. 
Multiple choice hunger and dehydration from tasting to digestion digestion of food digestion evs
Instantaneous source of energy is

  1. Proteins

  2. Fats

  3. Nucleic acids

  4. Glucose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Glucose is a monomer that after ingestion, does not gets digested and directly gets absorbed and converted into energy. Therefore, glucose is an instantaneous source of energy.

Protein, Fats, and Nucleic acid don't get directly converted into energy. So, they are not the instantaneous source of energy. 
So, the correct option is (D).

Multiple choice evs deficiency diseases need for nutrients nutrients needed by the body balanced diet and malnutrition food for health nutrition and its deficiency nutrition and its need

What does an inorganic compounds contain?

  1. Sodium Chloride

  2. Nutrients

  3. Oil

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

Sodium chloride (NaCl) is a classic example of an inorganic compound, as it is an ionic salt lacking carbon-hydrogen bonds. Oil, fats, and nutrients (like proteins/carbohydrates) are organic compounds.

Multiple choice evs deficiency diseases need for nutrients nutrients needed by the body balanced diet and malnutrition food for health nutrition and its deficiency nutrition and its need

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

The body burns fat after first exhausting the contents of the digestive tract along with glycogen (carbohydrates) reserves stored in muscle and liver cells. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation when the body has depleted its body fat, it begins to burn lean tissue and muscle (protein) as a fuel source.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Study the given statement and select the correct answer  

  1. Lipids are micromolecules but obtained under-macromolecular fraction due to their insoluble nature in aquous medium of a cell.

  2. water is the most aboundant chemical in living organism

  3. First respiratory substrate = Lipid

  4. DIhydroxy acetone occur in d and I form.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lipids are technically micromolecules (low molecular weight), but they are extracted in the acid-insoluble fraction because they form vesicles that precipitate with cell debris.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Identify the statement which is incorrect about absorption of lipids.

  1. The lipids are absorbed in laymp capillaries present with the villi

  2. From the micelles ,fatty acids and glycerol are absorbed into the intestinal cells by active transport

  3. Micelles are formed with the help of bile salts and phospholipids in intestinal lumen

  4. The lacteals after absorption of lipids contains chyle
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

........... prevents the rupturing of lysosomal membrane.

  1. Cholesterol

  2. Vit. A

  3. Testosterone

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

Vitamin A, testosterone and UV rays induce lysis of lysosomal membrane under acidic pH which makes options B, C and D incorrect. Cholesterol exhibit scavenging effect on free radicals as well as prevent osmotic rupture of lysosomal membrane which makes option A correct answer. 

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

The energy storing molecules in animals are
I. Glucose
II. Glycogen
III. Lipid
IV. Protein

  1. I and II

  2. II and III

  3. I, II and III

  4. II, III and IV

  5. I, II, III and Iv
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glycogen is also homopolysaccharide of D-glucose and serves as an energy storing molecule in animals as glucose as storage material can increase the osmotic pressure of storage cell enormously. Proteins do not serve as energy storage molecule. Fat and oil are storage lipids and are derivatives of hydrocarbon that produce enormous energy upon oxidation. Thus, the correct answer is B.