Alpha-helix is found in which level of protein structure?

Core Logic

Let's check each statement:

• Statement A is false: Lipids are generally water-insoluble.
• Statement B is true: Proteins are heteropolymers made of amino acids, known as polypeptides.
• Statement C is true: Polysaccharides are long polymeric chains of monosaccharides (sugars).
• Statement D is false: Adenine and guanine are substituted purines, not pyrimidines. (Cytosine, Uracil, and Thymine are pyrimidines).
• Statement E is true: Almost all enzymes are proteins (with some exceptions like ribozymes).

Step 1: Final Conclusion

Statements B, C, and E are correct.

Pattern Recognition

Knowing Purines = Adenine, Guanine (Pure As Gold) instantly marks D as incorrect. Eliminating D removes options 1 and 3. Knowing Lipids are non-polar (insoluble) eliminates A, leaving only option 2.

Chapter Mix

Class 11 Biology: Biomolecules

Core Logic

• Statement A is correct. Amino acids can be conceptualized as substituted methanes (an alpha-carbon substituted with an amino group, carboxyl group, hydrogen, and an R group).
• Statement B is incorrect. Serine contains a hydroxyl group (alcoholic amino acid). Aromatic amino acids are Tyrosine, Phenylalanine, and Tryptophan.
• Statement C is correct. Valine is a neutral amino acid (one amino group, one carboxyl group).
• Statement D is incorrect. Lysine is a basic amino acid, not acidic. (Glutamic acid and Aspartic acid are acidic).

Step 1: Final Conclusion

Only statements A and C are correct.

Pattern Recognition

Basic amino acids = HAL (Histidine, Arginine, Lysine). Knowing Lysine is basic eliminates D. Aromatic = Phenylalanine, Tyrosine, Tryptophan. Eliminates B.

Chapter Mix

Class 11 Biology: Biomolecules

Core Logic

From the secondary metabolites and proteins table in NCERT:

• Trypsin (A) is a classic proteolytic Enzyme. (A-III)
• Morphine (B) is a secondary metabolite classified as an Alkaloid. (B-IV)
• Concanavalin A (C) is a carbohydrate-binding protein known as a Lectin. (C-II)
• Collagen (D) is the most abundant protein in the animal world and serves as an Intercellular ground substance. (D-I)

Step 1: Final Conclusion

The correct matches are A-III, B-IV, C-II, D-I.

Pattern Recognition

Collagen = Intercellular ground substance (D-I) and Trypsin = Enzyme (A-III) are very common. Combining these gives only option 1.

Chapter Mix

Class 11 Biology: Biomolecules

Core Logic

Lyases are the enzymes that catalyse the removal of groups from substrates by mechanisms other than hydrolysis, leaving double bonds.

• Transferases are the enzymes that catalyse a transfer of a group between a pair of substrates.
• Isomerases catalyse inter-conversion of optical, geometric or positional isomers.
• Ligases catalyse the linking together of 2 compounds.

Pattern Recognition

Formation of a double bond upon removal of groups without water (non-hydrolytic cleavage) indicates Lyases.

Chapter Mix

Class 11 Biology: Biomolecules