Biomolecules Question And Answers

Biology Class 11 WBCHSE Biomolecules Question And Answers

Question 1. Name a carbohydrate that cannot be digested in the human body.
Answer:

Cellulose is a carbohydrate that cannot be digested in the human body. It is because humans do not have cellulase, an enzyme necessary for cellulose digestion.

Question 2. What is an amino sugar?
Answer:

Amino sugar

The sugar molecule in which the hydroxyl group has been replaced by an amino group, is known as an amino sugar. E.g., Glucosamine.

Biomolecules questions and answers PDF

Question 3. What is known as reducing sugar?
Answer:

Reducing sugar

The sugars which have free aldehyde or keto groups and act as reducing agents in alkaline solution, are called reducing sugars.

Question 4. What is roughage?
Answer:

Roughage

The undigested polysaccharides that are present in food, and are important for proper functioning of the alimentary canal, is together known as roughage.

It helps to regulate digestion and prevents constipation.

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Question 5. What do you mean by animal starch?
Answer:

Animal starch

Glycogen is called animal starch. Plants store excess glucose in the form of starch, similarly excess glucose is stored by animals in the form of glycogen. Hence, glycogen is so named.

Question 6. What do you mean by first and second class proteins?
Answer:

First class proteins: The proteins that contain all the essential amino acids, are known as first class  proteins. Animal proteins are the examples of first class proteins.

Second class proteins: The proteins that do not contain all the essential amino acids, are known as second class proteins. Plant proteins are the examples of second class proteins.

NEET biomolecules important questions with answers

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Question 7. What are peptide bonds?
Answer:

Peptide bonds

The bonds that exist between the carboxyl group of one amino acid and the amino group of the adjacent amino acid, in a polypeptide chain, are called peptide bonds. Peptide bond formation involves release of a molecule of water.

Question 8. What is known as saponification? What is saponification number?
Answer:

Saponification

The reaction in which fats are hydrolysed by alkali (sodium hydroxide or potassium hydroxide) yielding glycerol and alkali salts of fatty acids (soaps), is called saponification.

Saponification number

Number of milligrams of a base (like KOH), that is required to saponify one gram of a given ester (specifically glyceride), is known as saponification number of that ester.

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Question 9. What is iodine number?
Answer:

Iodine number

The amount of iodine (in grams) required by 100 g of fat for saturation of unsaturated fatty acids in it, is known as iodine number. This number determines the level of unsaturation in the lipids.

Question 10. What do you understand by ‘unit of nucleic acids’?
Answer:

‘unit of nucleic acids’

Nucleotide is the ‘unit of nucleic acids’. It is formed of a pentose sugar, nitrogenous base and phosphoric acid.

Question 11. Why is DNA called double helix and anti-parallel?
Answer:

DNA contains two strands that are coiled around each other, hence DNA is also called double helix. DNA contains two nucleotide strands that lie parallel to each other but oriented in opposite directions.

Each strand has a phosphoryl (5′) end and a hydroxyl (3′) end. The 3′ end of one strand faces 5′ end of the other strand, hence DNA is also called anti-parallel.

Class 11 biology biomolecules Q&A

Question 12. What are the nitrogenous bases present in DNA?
Answer:

The nitrogenous bases present in DNA are of two types—purines and pyrimidines. Purines include adenine and guanine, while pyrimidines include cytosine and thymine.

Question 13. What is known as genetic RNA?
Answer:

Genetic RNA

In many organisms RNA is the main gentic material which stores the genetic informations. Such RNA is called genetic RNA. These organisms do not contain DNA. E.g., TMV virus, measles virus, etc.

Question 14. What is known as DNA replication?
Answer:

DNA replication

The process by which a living cell synthesises a new DNA strand from an existing DNA strand, is called DNA replication.

Question 15. What is enzymology?
Answer:

Enzymology

The branch of science that deals with the study of structure, nomenclature, activity, etc., of enzymes, is known as enzymology.

Question 16. What is ribozyme?
Answer:

Ribozyme

Ribozyme is a type of ribosomal RNA (rRNA) molecule, that acts as an enzyme. It catalyses various cellular reactions, like, processing of RNAs, splicing of mRNA, viral replication, tRNA biosynthesis, etc. Ribonuclease P is an example of ribozyme.

Question 17. What are cofactors?
Answer:

Cofactors

The thermostable, non-protein part of the enzyme responsible for the catalytic activity of an apoenzyme, is called cofactor.

The apoenzyme and the cofactor together form holoenzyme which is the active structure of an enzyme.

Question 18. What is a prosthetic group?
Answer:

Prosthetic group

The non-protein part firmly attached to the protein part of the enzyme (apoenzyme), is called a prosthetic group. They together form the holoenzyme.

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Question 19. What is a co-enzyme?
Answer:

Co-enzyme

The organic non-protein part which is loosely attached to the protein part of the enzyme (apoenzyme) molecule is called a co-enzyme.

Question 20. What is an active site?
Answer:

Active site

The site of the enzyme to which the substrate molecule binds and undergoes a chemical reaction, is known as active site of that enzyme.

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Question 21. What is the turnover number of an enzyme?
Answer:

Turnover number of an enzyme

The maximum number of chemical conversion of substrate molecules that an active site will execute for unit(l) amount of enzyme concentration per second, is known as the turnover number of the enzyme. It describes the activity of the enzyme.

Question 22. What is a simple enzyme?
Answer:

Simple enzyme

The enzyme that is made up of only protein or
amino acid molecules, is called a simple enzyme. Example: Lysosyme, urease etc.

Question 23. What are allosteric enzymes?
Answer:

Allosteric enzymes

The enzymes which contain allosteric sites (regions on an enzyme, other than the active site), to which the modulator molecules can bind and influence the activity of the enzyme) are called allosteric enzymes.

Question 24. Why do many enzymes remain inactive within living cells?
Answer:

Many enzymes remain inactive within living cells, because their main function is to regulate specific reactions. When needed they become active.

Their activation also depends on some other factors, like, pH, temperature, availability of substrates, presence of activator, enhancer and inhibitor molecules.

Question 25. What are isoenzymes or isozymes?
Answer:

Isoenzymes or isozymes

The isoenzymes or isozymes are different forms of an enzyme, varying in structural constitution but catalysing similar chemical reactions. E.g., Lactate dehydrogenase has 5 isoenzymes.

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Question 26. What are proenzymes?
Answer:

Proenzymes

The substances from which enzymes are synthesised through some metabolic actions, are  called proenzymes. For example, Pepsinogen is a proenzyme of pepsin.

Question 27. What are exoenzymes?
Answer:

Exoenzymes

The enzymes which are synthesised within the cells, but are secreted outside the cells, where they carry out their functions, are known as exoenzymes.

For example, the digestive enzymes are synthesised inside the cells of different glands but they act inside the alimentary canal.

Question 28. What are holoenzymes?
Answer:

Holoenzymes

The active enzyme structures consisting of apoenzyme and cofactor molecules, are called holoenzymes.

Question 29. Why is the forehead and the body wiped with wet cloth, during fever?
Answer:

During fever, the temperature of the body rises. This high temperature may affect the activity of the enzymes present in the body.

This may, in turn, affect the metabolic reactions occurring within the body. Hence, the body and the forehead is wiped with wet cloth, to lower the body temperature, which will in turn protect the  enzymes in the body.

Biology Class 11 WBCHSE Biomolecules Short Answer Type Questions

Question 1. What is ketogenic amino acid?
Answer: The amino acid which produces ketone bodies in the body (liver) is known as ketogenic amino acid. Example—Leucine.

Question 2. Give three examples of essential amino acids.
Answer: Valine, lysine and methionine are essential amino acids.

Question 3. What is phosphoprotein?
Answer: Proteins which remain combined with phosphoric acids, are known as phosphoproteins.

Question 4. Give an example of chromoprotein.
Answer: Haemoglobin is a chromoprotein.

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Question 5. What is a pentose sugar?
Answer: Simple sugars containing five carbon atoms are called pentose sugars.

Question 6. What is ‘fruit sugar’?
Answer: Fructose is known as fruit sugar.

Question 7. Why is glucose known as ‘aldose sugar’?
Answer: Glucose contains an aldehyde (-CHO) group at first carbon, hence known as aldose sugar.

Question 8. Give three examples of monosaccharides.
Answer: Glucose, fructose and galactose are examples of monosaccharides.

Question 9. What is a disaccharide?
Answer: Two molecules of monosaccharides are linked together by a glycosidic bond to form a disaccharide.

Question 10. Give two examples of disaccharides.
Answer: Maltose and sucrose are examples of disaccharides.

Question 11. What is ‘malt sugar’?
Answer: Maltose is malt sugar.

Question 12. Give two examples of sulphur containing amino acids.
Answer: Cysteine and methionine are sulphur containing amino acids.

Question 13. Give two examples of acidic amino acids.
Answer: Glutamic acid and aspartic acid are acidic amino acids.

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Question 14. Give three examples of homopolysaccharides.
Answer: Cellulose, glycogen and starch are homopolysaccharides.

Question 15. What are the components of nucleotide?
Answer: Nitrogenous base, pentose sugar and phosphate are the components of a nucleotide.

Question 16. Name four main elements found in animal body.
Answer: Carbon, hydrogen, oxygen and nitrogen are mainly found in the animal body.

Question 17. Name one common sugar found in animal body.
Answer: Glucose.

Short answer questions on biomolecules 

Question 18. Which lipid is responsible for the disease related to high blood pressure?
Answer: Cholesterol.

Question 19. Which one is the 21st amino acid?
Answer: Selenocystein.

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Question 20. What is triglyceride?
Answer: Triglyceride is a compound formed in combination with one molecule of glycerol and three molecules of fatty acid.

Question 21. What is ester linkage?
Answer: The linkage between glycerol and fatty acid is known as ester linkage.

Question 22. What is nucleoside?
Answer: Nitrogenous base and pentose sugar together
without phosphoric acid is known as nucleoside.

Question 23. Who discovered the double helix structure of DNA?
Answer: J. D. Watson and F.H.C. Crick (1953) discovered the double helix structure of DNA.

Question 24. What is proenzyme?
Answer: The inactive state of an enzyme from which the active enzyme is formed is known as proenzyme.

Question 25. Give two examples of proenzyme.
Answer: Pepsinogen and trypsinogen are examples of proenzymes.

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Question 26. What is isoenzyme?
Answer: Enzymes that catalyse same reactions but have different structures are known as isoenzymes.

Question 27. What is antienzyme?
Answer: The agents that destroy or inhibit the activity of the enzymes are called antienzymes.

Question 28. Give one example of isoenzyme.
Answer: Lactate dehydrogenase.

Question 29. Where is rRNA synthesised?
Answer: Nucleolus.

Question 30. What is holoenzyme?
Answer: Apoenzyme (protein) and cofactor together is known as holo enzyme.

Question 31. What are abzymes?
Answer: Antibodies with catalytic activity are known as abzymes.

Question 32. Give two examples of non-reducing sugar.
Answer: Sucrose and starch.

Question 33. Give two examples of reducing sugar.
Answer: Glucose and fructose.

Question 34. What is glycerol?
Answer: The alcohol having three hydroxyl (-OH) groups is known as glycerol.

Question 35. What is reverse transcription?
Answer: The process of synthesis of DNA from RNA is known as reverse transcription.

Question 36. What is transcription?
Answer: The process of synthesis of RNA from DNA is known as transcription.

Question 37. What is ribozyme?
Answer: The rRNA molecule capable of showing catalytic activity like enzyme, is known as ribozyme.

Question 38. What is codon?
Answer: The triplet base found in mRNA which recognizes one specific amino acid during protein synthesis is known as codon.

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Question 39. What do you mean by anticodon?
Answer: The triplet base found in tRNA responsible for base pairing with the codon of mRNA during translation is known as anticodon.

Question 40. Which biomolecule is important for carrying hereditary information?
Answer: DNA.

Question 41. Who first used the term enzyme?
Answer: W. Kuhne first used the term enzyme.

Question 42. Give one example where RNA is the genetic material.
Answer: Tobacco mosaic virus.

Question 43. Which type of RNA contains codons?
Answer: mRNA contains codon.

Question 44. What is the function of tRNA?
Answer: The function of tRNA is to carry activated amino acids to mRNA containing specific codons during protein synthesis.

Question 45. Who discovered tRNA structure?
Answer: R. Holley (1965).

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Question 46. Who discovered that in a DNA, A=T and G=C?
Answer: E.Chargaff (1950).

Question 47. Write the name of any one amino acid, sugar nucleotide and fatty acid.
Answer: Alanine is one amino acid, adenylic acid is a nucleotide and linolenic acid is a fatty acid.

Question 48. Can you attempt building models of biomolecules using commercially available atomic models (Ball and stick models)?
Answer: Yes, we can attempt building models of biomolecules using commercially available atomic models.

Question 49. Reaction given below is catalysed by oxidoreductase between two substrates, A and A’, complete the reaction.
Answer: A reduced + A’ oxidised →A oxdised + A’ reduced

Question 50. State True or False:
Enzymes are not heat and pH sensitive.
Answer: False.