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Organic Chemistry

Biomolecules

Browse 101 questions on Biomolecules. Click on any question to view the detailed answer and explanation.

What product is obtained when Glucose is treated with Hydrogen Iodide (HI) for a prolonged period, and what does this reaction prove?.

Carbohydrates

Glucose reacts with hydroxylamine (NH2OH) to form an oxime. What structural feature of glucose does this reaction confirm?.

Carbohydrates

When glucose is oxidized by bromine water (a mild oxidizing agent), it forms Gluconic acid. What specific conclusion can be drawn from this?.

Carbohydrates

Acetylation of glucose with acetic anhydride gives glucose pentaacetate. What does this indicate about the glucose structure?.

Carbohydrates

On oxidation with nitric acid (a strong oxidizing agent), both glucose and gluconic acid yield Saccharic acid (a dicarboxylic acid). What does this in...

Carbohydrates

Why does Glucose pentacetate not react with hydroxylamine?.

Carbohydrates

What are the specific names given to the two cyclic hemiacetal forms of glucose that differ only in the configuration of the hydroxyl group at C1?.

Carbohydrates

What distinguishes a Reducing Sugar from a Non-Reducing Sugar?.

Carbohydrates

Fructose belongs to which class of ketohexoses and what is its specific ring structure called?.

Carbohydrates

Why is Sucrose considered a non-reducing sugar?.

Carbohydrates

What is 'Invert Sugar'?.

Carbohydrates

Describe the glycosidic linkage found in Maltose.

Carbohydrates

What are the hydrolysis products of Lactose and what type of glycosidic linkage connects them?.

Carbohydrates

Starch is a mixture of two components. What are they and which one is water-soluble?.

Carbohydrates

What is the key structural difference between Amylose and Amylopectin regarding linkage?.

Carbohydrates

Why can humans not digest cellulose?.

Carbohydrates

What is Glycogen often called and where is it primarily stored in the body?.

Carbohydrates

What does the 'D' in D-glucose signify?.

Carbohydrates

What is the general formula for carbohydrates, and what is a notable exception that fits the formula but is not a carbohydrate?.

Carbohydrates

Despite having an aldehyde group, Glucose does not give the Schiff's Test. Why?.

Carbohydrates

How many carbon atoms are in the pyranose ring of glucose?.

Carbohydrates

What makes an amino acid 'Essential'?.

Proteins

Name two amino acids that contain sulphur.

Proteins

Which is the only optically inactive natural amino acid and why?.

Proteins

What is a Zwitter Ion?.

Proteins

What is the 'Isoelectric Point'?.

Proteins

Chemically, what type of bond is a peptide bond?.

Proteins

Differentiate between Fibrous and Globular proteins based on solubility.

Proteins

What constitutes the 'Primary Structure' of a protein?.

Proteins

What forces stabilize the \alpha-helix secondary structure?.

Proteins

In a \beta-pleated sheet structure, how are the peptide chains held together?.

Proteins

What is 'Tertiary Structure'?.

Proteins

What happens to the Primary Structure of a protein during denaturation?.

Proteins

Give a common example of protein denaturation involving temperature change.

Proteins

Is Keratin (found in hair/wool) a fibrous or globular protein?.

Proteins

Is Insulin a fibrous or globular protein?.

Proteins

Chemically, what are most enzymes?.

Enzymes

How do enzymes affect the activation energy of a reaction?.

Enzymes

What is meant by the 'lock and key' mechanism of enzyme action?.

Enzymes

Which enzyme converts maltose into glucose?.

Enzymes

Name the vitamins that are water-soluble.

Vitamins

Why must Vitamin C be supplied regularly in the diet?.

Vitamins

Which vitamin deficiency causes Xerophthalmia (hardening of cornea)?.

Vitamins

Deficiency of Vitamin B1 (Thiamine) leads to which disease?.

Vitamins

Pernicious anaemia is caused by the deficiency of which vitamin?.

Vitamins

Which vitamin is responsible for the coagulation of blood?.

Vitamins

Vitamin B12 contains a specific metal ion. Which one?.

Vitamins

Rickets in children and Osteomalacia in adults is caused by deficiency of:.

Vitamins

What are the three chemical components of a nucleotide?.

Nucleic Acids

What is the difference between a Nucleoside and a Nucleotide?.

Nucleic Acids

What specific sugar is found in DNA?.

Nucleic Acids

What specific sugar is found in RNA?.

Nucleic Acids

Which nitrogenous base is present in DNA but not in RNA?.

Nucleic Acids

Which nitrogenous base replaces Thymine in RNA?.

Nucleic Acids

What type of linkage connects the nucleotides in a nucleic acid chain?.

Nucleic Acids

In the DNA double helix, how many hydrogen bonds form between Guanine (G) and Cytosine (C)?.

Nucleic Acids

In the DNA double helix, how many hydrogen bonds form between Adenine (A) and Thymine (T)?.

Nucleic Acids

What is the primary function of DNA?.

Nucleic Acids

Name the three types of RNA involved in protein synthesis.

Nucleic Acids

Which reagent is used to detect the presence of reducing sugars in a solution, producing a red precipitate?.

Carbohydrates

Glucose and Galactose differ in configuration at which carbon atom?.

Carbohydrates

What is the product of the reaction between an amino acid and nitrous acid (HNO2)?.

Proteins

What is the 'Quaternary Structure' of a protein?.

Proteins

What suffix is typically added to the substrate name to name an enzyme?.

Enzymes

What is the richest source of Vitamin C?.

Vitamins

Where is DNA primarily located in the cell?.

Nucleic Acids

Which naturally occurring sugar is the sweetest?.

Carbohydrates

Which amino acid is formed by the hydrolysis of protein in the stomach?.

Proteins

Insulin is a hormone. Chemically, what is it?.

Proteins

What is Mutarotation?.

Carbohydrates

Which test is used to detect the presence of peptide bonds (proteins)?.

Tests for Proteins, Fats & carbohydrates

Which test is specific for carbohydrates?.

Tests for Proteins, Fats & carbohydrates

Molisch's Test: 1. What are the reagents used? 2. What is the positive observation?

Tests for Proteins, Fats & carbohydrates

Molisch's Test Principle: The violet color is due to the condensation of 1-naphthol with what compound?

Tests for Proteins, Fats & carbohydrates

Fehling's Test: 1. What indicates a positive result? 2. What is the chemical formula and color of the precipitate formed?

Tests for Proteins, Fats & carbohydrates

Fehling's vs. Benedict's Reagent: To prevent precipitation of Cu(OH)2Cu(OH)_2 , Cu2+Cu^{2+} ions are complexed with which specific ions in each reagen...

Tests for Proteins, Fats & carbohydrates

Tollen's Test: 1. What is the common name for Tollen's reagent? 2. What is the positive observation?

Tests for Proteins, Fats & carbohydrates

Barfoed's Test: What is the main purpose of this test?

Tests for Proteins, Fats & carbohydrates

Barfoed's Reagent: What is the composition of this reagent?

Tests for Proteins, Fats & carbohydrates

Seliwanoff's Test: 1. What does this test distinguish? 2. What is the positive result for a Ketohexose?

Tests for Proteins, Fats & carbohydrates

Seliwanoff's Principle: Why do Ketoses react faster than Aldoses in this test?

Tests for Proteins, Fats & carbohydrates

Iodine Test: 1. What is the positive observation for Starch? 2. What complex is formed?

Tests for Proteins, Fats & carbohydrates

Hydrolysis Test: Why does Sucrose NOT give a positive Fehling's/Tollen's test directly?

Tests for Proteins, Fats & carbohydrates

Acrolein Test: 1. What reagent is used? 2. What indicates a positive result?

Tests for Proteins, Fats & carbohydrates

Solubility Check: Are Fats and Oils soluble in water?

Tests for Proteins, Fats & carbohydrates

Theory: Chemically, what are fats and oils known as?

Tests for Proteins, Fats & carbohydrates

Biuret Test: 1. What does this test detect? 2. What is the positive color?

Tests for Proteins, Fats & carbohydrates

Biuret Reagents: Which two chemical solutions are required for the Biuret test?

Tests for Proteins, Fats & carbohydrates

Ninhydrin Test: What is the name and color of the compound formed when proteins react with Ninhydrin?

Tests for Proteins, Fats & carbohydrates

Xanthoproteic Test: 1. What reagent is used? 2. What specific part of the protein does it react with?

Tests for Proteins, Fats & carbohydrates

Xanthoproteic Observations: Describe the color change when Conc. HNO3HNO_3 is added followed by Alkali ( NaOHNaOH ).

Tests for Proteins, Fats & carbohydrates

Practical Application: Based on the lab manual, which foodstuff tested positive for both Fats and Proteins?

Tests for Proteins, Fats & carbohydrates

To which class of nitrogenous bases do Adenine and Guanine belong?.

Nucleic Acids

To which class of nitrogenous bases do Cytosine, Thymine, and Uracil belong?.

Nucleic Acids

Cheilosis (fissuring at corners of mouth) is caused by deficiency of:.

Vitamins

What is the monomer unit of Cellulose?.

Carbohydrates

What is formed when Glucose is treated with Tollen's reagent?.

Carbohydrates

Which specific bond stabilizes the tertiary structure of proteins by linking two sulfur atoms?.

Proteins

Are \alpha-D-glucose and \beta-D-glucose enantiomers?.

Carbohydrates

What functional groups are present in an amino acid?.

Proteins

At which level of protein structure does the shape of the active site of an enzyme form?.

Proteins