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Which one of the following statements on protein conformation is NOT true?
(1) Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot.
(2) Infrared spectroscopy can be used to deduce hydrogen bonding in peptides.
(3) Three dimensional structures of protein composed of 100 amino acids can be obtained by nuclear magnetic resonance spectroscopy
(4) Globular proteins have α-helical and ß- sheet components
Understanding Protein Conformation: Key Facts and Misconceptions
Proteins adopt specific conformations that determine their function. Various techniques like Ramachandran plots, infrared spectroscopy, and NMR help analyze these structures. However, not all commonly believed facts are correct.
Correct Answer:
The incorrect statement is:
(1) Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot.
Explanation of the Answer Choices
1. The Ramachandran Plot Does NOT Show Side-Chain Dihedral Angles (Incorrect Statement)
- The Ramachandran plot only depicts the φ (phi) and Ψ (psi) backbone dihedral angles of amino acid residues.
- It does not show the side-chain (χ, chi) angles, which are analyzed using a rotamer plot.
2. Infrared Spectroscopy Identifies Hydrogen Bonding (Correct Statement)
- Infrared (IR) spectroscopy measures bond vibrations.
- Hydrogen bonds shift absorption peaks, helping identify α-helices, β-sheets, and random coils.
3. NMR Can Determine Protein Structures of ~100 Amino Acids (Correct Statement)
- Nuclear Magnetic Resonance (NMR) spectroscopy determines 3D structures of small to medium proteins (≤100-150 residues).
- Larger proteins require X-ray crystallography or cryo-EM.
4. Globular Proteins Contain Both α-Helices and β-Sheets (Correct Statement)
- Most globular proteins have both α-helices and β-sheets, allowing compact folding.
- Examples include hemoglobin and myoglobin.
Significance of Protein Conformation Analysis
1. Understanding Protein Folding Disorders
- Misfolded proteins cause diseases like Alzheimer’s and Parkinson’s.
2. Drug Discovery and Design
- Structural knowledge helps in designing target-specific drugs.
3. Engineering Synthetic Proteins
- Protein conformation guides bioengineering applications.
Conclusion
While IR spectroscopy, NMR, and globular protein structures are correctly described, the Ramachandran plot does not depict side-chain dihedral angles. This common misconception highlights the importance of understanding protein analysis techniques correctly.
27 Comments
Suman bhakar
March 27, 2025Ok sir
pallavi gautam
March 28, 2025okay sir
Akshay mahawar
April 2, 2025Done 👍
Kabeer Narwal
April 6, 2025👍
Komal Sharma
August 14, 2025The Ramachandran plot only depicts the φ (phi) and Ψ (psi) backbone dihedral angles of amino acid residues. It does not show the side-chain (χ, chi) angles, which are analyzed using a rotamer plot so this option is incorrect
Meenakshi Choudhary
September 9, 2025The Ramachandran plot only depicts the φ (phi) and Ψ (psi) backbone dihedral angles of amino acid residues. It does not show the side-chain (χ, chi) angles, which are analyzed using a rotamer plot.
Aakansha sharma Sharma
September 25, 2025(1) Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot
Kirti Agarwal
September 26, 2025Statement A
Dharmpal Swami
September 26, 2025Dihedral angle on ramachandra plot show only phi and sai backobone
Neha Yadav
September 26, 2025Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot
Soniya Shekhawat
September 26, 2025In Ramachandra plot are be show the depict of phi and psi backbone dehedral amino acid residue and not show the side chain of angle is analysed at rotamer plot.
Muskan Yadav
September 26, 2025Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot.
Pallavi Ghangas
September 26, 2025Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot.
Priti khandal
September 27, 2025Dihedral angle of side chain in amino acid are depicted in the Ramachandra blot
Devika
September 27, 2025Dihydral angles of side chains in amino acids are depicted in ramachandran plot
Kavita Choudhary
September 27, 2025Dihydril angel of side chain amino acid are decipated in the Ramachandran plot becose it dose not show the side chain and which are analyzing rotemar plot
Kajal
September 28, 2025Ramachandran plot does not depict dihedral angle of Side chain
Mohd juber Ali
September 28, 2025The incorrect statement is 1
Ramachandaran plot depict only phi and sai dihedral angle backbone of amino acid residue not depict dihedral angle of side chain
Mansukh Kapoor
September 28, 2025The correct answer is option 1st
Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot, this statement is not correct for ramachandra plot
Manisha choudhary
September 28, 20251st option is incorrect
Ramachandran plot does not show side chain dihedral angle Ramchandran plot only phinand psi backbone dihedral angle
Side chain angle rotamer plot m plot Kiya jata
Infrared spectroscopy identify hydrogen bonding
Infrared spectroscopy measure bond vibration
Hydrogen bond shift absorption peak
Alpha helix,beta sheet ,random coil ko identify krne m help krti h
NMR identify 3-d structure of small to medium protein
Larger protein k liye xray crystelography
Sakshi Kanwar
September 28, 2025Ramachandran plot only depicts the phi and psi backbone dihedral angles of amino acid not side chain of amino acid
roopal sharma
September 28, 2025phi and psi dihedral angles only depicts backbone and does not depict side chains.
Anurag Giri
September 28, 2025In Ramachandra plot are be show the depict of phi and psi backbone dehedral amino acid residue and not show the side chain of angle is analysed
Arushi Saini
September 28, 2025Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot
Heena Mahlawat
September 28, 2025Dihedral angles of side chains aren’t depicted in ramachandran plot
Avni
September 29, 2025the Ramachandran plot does not depict side-chain dihedral angles
Neeraj Sharma
October 5, 2025Dihedral angles of side chains are not depicted on ramachandran plot infact there is no relation in ramachandran plot and side chains ramachandran plot is based on alphaC-C and alphaC-N bonds i.e. backbone not side chains