Biomolecules

CBSE Class 12 Chemistry · every board question from this chapter, 2023–2026 · 2 of them repeated across years

• In the ring structure of fructose, the anomeric carbon is2026
• On hydrolysis, which of the following carbohydrates gives only β -glucose?2026
• Each polypeptide in a protein has amino acids linked with each other in a specific sequence and it is this sequence of amino…2026
• The base which is present in DNA but not in RNA is:2026
• Identify the polysaccharide among the following:2026
• Nucleic acids are polymers of:2026
• On hydrolysis, which of the following carbohydrates gives only glucose?2026
• An example of non-reducing sugar is2026
• Proteins are polymers of α -amino acids which are joined to each other by:2026
• The deficiency of which of the following vitamins causes increased fragility of red blood cells and muscular weakness:2026
• Which of the following reactions is not explained by the open chain structure of glucose?2026
• The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino…2026
• On hydrolysis, which of the following carbohydrates gives only glucose?2026
• Which of the following is a water-soluble vitamin?2026
• Assertion (A): D(+)- Glucose is dextrorotatory in nature. Reason (R): (+) represents dextrorotatory nature and D represents the…2026
• Assertion: The pentaacetate of glucose does not react with H_2 N-OH. Reason (R): It indicates the absence of free -CHO group in…2026
• Assertion: Glucose gets oxidized to six carbon gluconic acid on reaction with bromine water. Reason (R): The carbonyl group is…2026
• Assertion: The pentaacetate of glucose does not react with H_2 N-OH. Reason (R): It indicates the presence of free - CHO group in…2026
• Assertion: The two strands of DNA are complementary to each other. Reason (R): The hydrogen bonds are formed between specific…2026
• What is the effect of denaturation on the structure of proteins? What are the common types of secondary structures of proteins?2026
• Name the sugar present in sugarcane. What are the hydrolysis products of this sugar? Is this sugar a reducing sugar?2026
• Differentiate between the following: (i) Peptide linkage and Glycosidic linkage (ii) Essential amino acids and Non-essential…2026
• How do you explain the following? Presence of an aldehyde group in glucose Presence of a primary alcoholic group in glucose2026
• What are the products obtained on hydrolysis of sucrose? What are essential amino acids?2026
• Write the hydrolysis products of lactose. What are non-essential amino acids?2026
• Differentiate between the following: (i) Fibrous protein and Globular protein (ii) Peptide linkage and Phosphodiester linkage2026
• What are the hydrolysis products of the following? Lactose DNA containing Thymine2026
• Differentiate between the following: 2 × 1 (i) Acidic amino acids and basic amino acids (ii) Nucleotide and Nucleoside2026
• Write any two fat soluble vitamins. How will you confirm the presence of five - OH groups in a glucose molecule, which are…2026
• Name the disease caused by the deficiency of Vitamin A. How will you confirm the presence of carbonyl group as an aldehydic group…2026
• How do you explain the following? Presence of a straight chain in glucose Presence of five - OH groups in glucose which are…2026
• How do you explain the following? Presence of a carbonyl group in glucose Presence of five - OH groups in glucose2026
• Name two water-soluble vitamins. How will you prove the absence of free - CHO group in the cyclic structure of glucose molecule?2026
• Define the following terms: Anomers Invert sugar Glycosidic linkage2026
• Write the reactions of D-Glucose with the following: HI Br_2 water Conc. HNO_32026
• How do you explain the presence of following in open structure of glucose? all the six carbon atoms are in a straight chain. five…2026
• Define the following term: 2+1 Reducing sugar Differentiate between the following: (i) Fibrous proteins and globular proteins…2026
• Define the following terms: 1+1+1 (i) Invert Sugar (ii) Polysaccharides On the basis of structure differentiate between fibrous…2026
• Define the following terms: 2+1 (i) Denaturation as related to proteins (ii) Oligosaccharides On the basis of structure…2026
• Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc. Proteins and…2026
• Carbohydrates are optically active polyhydroxy aldehydes or ketones or the compounds which produce such units on hydrolysis. They…2026
• In the Haworth structure of the following carbohydrate, various carbon atoms have been numbered. The anomeric carbon is numbered…2025
• Which of the following is/are examples of denaturation of protein?2025
• Which of the following statements is not true about glucose?2025
• Nucleotides are joined together by2025
• Pyranose ring of glucose is formed due to the reaction between:2025
• Furanose ring of fructose is formed due to reaction between:2025
• Deficiency of vitamin B_1 causes the disease:2025
• 'Scurvy' is caused due to the deficiency of:2025
• Scurvy is caused due to deficiency of2025
• α -D-glucose and β -D-glucose differ from each other with respect to the:2025
• α -helix structure refers to:2025
• Assertion: Maltose is a reducing sugar. Reason(R): One of the two glucose units can open to expose free aldehydic group in…2025
• Assertion: Vitamin D cannot be stored in our body. Reason (R): Vitamin D is fat soluble vitamin and is not excreted from the body…2025
• Assertion: Vitamin K can be stored in our body. Reason (R): Vitamin K is a water soluble vitamin.2025
• Assertion: All naturally occurring α -amino acids except glycine are optically active. Reason (R): Most naturally occurring amino…2025
• Write two differences between Amylose and Amylopectin components of starch.2025
• Give reasons for the following: The melting points of α -amino acids are generally higher than that of the corresponding…2025
• What are the hydrolysis products of: 2 Sucrose Lactose2025
• Write the reactions involved when D-glucose is treated with the following reagents: (1+1=2) HCN Br_2 water2025
• What is meant by essential amino acids? Why are amino acids amphoteric in nature?2025
• The two strands in DNA are not identical but complementary. Explain. What products would be formed when DNA is hydrolysed?2025
• How do you explain the following? Presence of an aldehydic group in glucose. Presence of five - OH groups in glucose.2025
• Differentiate between: Essential amino acids and Non-essential amino acids Peptide linkage and Glycosidic linkage Fibrous protein…2025
• Define the following terms: Glycosidic linkage Invert sugar Oligosaccharides2025
• Write the reaction of D-Glucose with the following: HCN Br_2 water (CH_3 CO)_2 O2025
• Define the following terms: Native protein Nucleotide Essential amino acid2025
• Write the reaction when D-glucose reacts with the following: (i) NH_2 OH (ii) Acetic anhydride Why vitamin C cannot be stored in…2025
• Name the type of linkage responsible for the formation of proteins from α -amino acids. Write any two differences between DNA and…2025
• Name the vitamin which is responsible for coagulation of blood. 1 What is meant by denaturation of protein? Give an example.2025
• Name the vitamin whose deficiency causes pernicious anaemia. Write any two differences between globular and fibrous proteins.2025
• What is the difference between native protein and denatured protein? (1+1+1=3) Which one of the following is a disaccharide?…2025
• Write the product obtained when D-glucose reacts with H_2 N-OH. Amino acids show amphoteric behaviour, why? Why vitamin C cannot…2025
• Carbohydrates are polyhydroxy aldehydes or ketones that represent enormous structural diversity in terms of the arrangement of…2025
• The α -amino acids are the building blocks of proteins. All α -amino acids exist as zwitter ion due to which they show amphoteric…2025
• Ribose and 2-deoxyribose have an important role in biology. Among the most important derivatives are those with phosphate groups…2025
• The specific sequence in which amino acids are arranged in a protein is called its2024
• Maltose is made up of:2024
• Two among the three components of DNA are β -D-2-deoxyribose and a heterocyclic base. The third component is:2024
• Which of the following acids represents Vitamin C?2024
• Nucleotides are composed of a:2024
• 'Scurvy' is caused by the deficiency of vitamin:2024
• The vitamin which plays an important role in coagulating blood is:2024
• 'Night-Blindness' is caused by the deficiency of Vitamin:2024
• Which functional groups of glucose interact to form cyclic hemiacetal leading to pyranose structure?2024
• All proteins on hydrolysis give:2024
• Assertion: Uracil base is present in DNA. Reason (R): DNA undergoes self-replication.2024
• Assertion: Vitamin C cannot be stored in our body. Reason (R): Vitamin C is water soluble and readily excreted in urine.2024asked 2×
• Assertion: Uracil base is present in RNA. Reason (R): RNA undergoes self-replication.2024
• Assertion: Fructose is a reducing sugar. Reason (R): Fructose does not reduce Fehling solution and Tollen's reagent.2024
• Write the reactions of glucose with: H_2 N-OH Br_2 water2024
• What happens when D-glucose is treated with the following reagents? H_2 N-OH (CH_3 CO)_2 O2024
• Write the reactions of glucose with: HI (CH_3 CO)_2 O2024
• Define the following terms: Essential amino acids Nucleotide2024
• What happens when D-glucose is treated with the following reagents? Br_2 water HCN2024
• Classify the following sugars into monosaccharides and disaccharides: Galactose, Glucose, Lactose and Maltose2024
• What happens when D-glucose is treated with the following reagents? HI Conc. HNO_32024
• Define the following terms: Peptide linkage Essential amino acids2024
• Classify the following sugars into monosaccharides and disaccharides: Sucrose, Lactose, Glucose, Fructose2024
• Give reaction of glucose with the following: HCN Conc. HNO_32024
• What happens when Glucose reacts with Nitric acid? Write chemical equation. Write one structural difference between DNA and RNA.…2024
• Define the following terms: Denaturation of protein Invert sugar2024
• What happens when glucose reacts with bromine water? Write chemical equation. Two bases are mentioned below, identify which is…2024
• Classify the following sugars into monosaccharides and disaccharides: Fructose, Lactose, Glucose, Maltose2024
• What happens when Glucose reacts with HI? Write chemical equation. Which type of bond holds a DNA double helix together? 1 × 22024
• Explain the following terms: Essential amino acids Peptide bond Denaturation 1 × 32024
• Define the following terms: Non essential amino acids. Monosaccharides Anomers 1 × 32024
• Define the following terms: Glycosidic linkage Primary structure of protein Disaccharides 1 × 32024
• Answer the following: (any three) What is peptide linkage? What type of bonds hold a DNA double helix together? Which one of the…2024
• Carbohydrates are essential for life in both plants and animals. Carbohydrates are used as storage molecules as starch in plants…2024
• Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds…2024
• Proteins are the most abundant biomolecules of the living system. Proteins are the polymers of about twenty different α -amino…2024
• Which of the following structures represents α -D-glucose?2023
• Helical structure of proteins is stabilized by:2023
• On hydrolysis, which of the following carbohydrates gives only glucose?2023
• When D-glucose reacts with HI, it forms2023
• Proteins are polymers of2023
• A vitamin which plays a vital role in the clotting of blood is:2023
• Which of the following vitamins is water soluble?2023
• In the ring structure of glucose, the anomeric carbon is:2023
• Deficiency of Vitamin B causes:2023
• Which of the following statements is not true about glucose?2023
• β -pleated sheet structure in proteins refers to2023
• Hydrolysis of sucrose is called2023
• On hydrolysis, which of the following carbohydrates gives only glucose?2023
• On hydrolysis, which of the following carbohydrates gives glucose and galactose?2023
• On hydrolysis, which of the following carbohydrates gives glucose and fructose?2023
• The deficiency of which of the following vitamins causes Scurvy?2023
• Deficiency of which of the following vitamins causes Pernicious anaemia?2023
• The deficiency of which of the following vitamins causes 'Rickets'?2023
• The glycosidic linkage involved in linking the glucose units in amylase part of starch is:2023
• An α -helix is a structural feature of:2023
• Which of the following is a non-reducing sugar?2023
• Assertion: Proteins are polymers of α -amino acids connected by a peptide bond. Reason (R): A tetrapeptide contains 4 amino acids…2023
• Assertion: Vitamin C cannot be stored in our body. Reason (R): Vitamin C is fat soluble and is excreted from the body in urine.2023
• Assertion: The backbone of DNA and RNA molecules is a chain consisting of heterocyclic base, pentose sugar and phosphate group.…2023
• What are nucleic acids? Why two strands in DNA are not identical but are complementary? 1 × 22023
• (i) How are carbohydrates stored in animal body? Mention any one organ where they are present. (ii) What is the basic structural…2023
• What is the difference between a nucleoside and nucleotide? 2 × 1 What products would be formed when a nucleotide from DNA…2023
• Define denaturation of protein. What is the effect of denaturation on the structure of protein?2023
• Give the reaction of glucose with hydrogen cyanide. Presence of which group is confirmed by this reaction?2023
• Write chemical reaction to show that open structure of D-glucose contains the straight chain. What type of linkage is responsible…2023
• Write two differences between DNA and RNA. 1 × 22023asked 2×
• Give the reaction of glucose with acetic anhydride. Presence of which group is confirmed by this reaction?2023
• Give the reaction of heating glucose with hydroxylamine. Presence of which group is confirmed by this reaction?2023
• Give reasons for any 3 of the following observations: Penta-acetate of glucose does not react with hydroxylamine. Amino acids…2023
• What are the hydrolysis products of (i) Lactose, (ii) Maltose?2023
• Write the product when D-glucose reacts with conc. HNO_3. Amino acids show amphoteric behaviour. Why? Write one difference…2023
• Write the structure of product when D-Glucose reacts with the following: (any three) HI Conc. HNO_3 Br_2 water HCN2023
• What are the hydrolysis products of (i) Lactose, (ii) Maltose? Give the basic structural difference between starch and cellulose.2023
• Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc.…2023
• Carbohydrates are optically active polyhydroxy aldehydes and ketones. They are also called saccharides. All those carbohydrates…2023

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