3. On a Ramachandran plot – glycine, L-Ala and L-Pro were plotted. Which statement is correct?
(1) L-alanine will occupy greatest area
(2) All amino acids will occupy same area
(3) L-alanine and glycine will occupy similar area
(4) Smallest are would be occupied by L-Proline
Ramachandran Plot: Understanding Glycine, L-Alanine, and L-Proline
The Ramachandran plot is a crucial tool in structural biology, representing the allowable phi (ϕ) and psi (ψ) angles of amino acids in a polypeptide chain. Different amino acids occupy different regions based on their side-chain flexibility and steric hindrance.
Which Amino Acid Occupies the Smallest Area?
Given the amino acids glycine, L-alanine, and L-proline, the correct answer is:
(4) Smallest area would be occupied by L-Proline
Understanding the Distribution on the Ramachandran Plot
- Glycine:
- Occupies the largest area due to its small hydrogen (-H) side chain.
- Has more conformational freedom, appearing in both right- and left-handed helices.
- L-Alanine:
- Slightly more restricted than glycine due to its methyl (-CH₃) side chain.
- Occupies a smaller region than glycine but still covers a broad area.
- L-Proline:
- Most restricted amino acid due to its cyclic imino side chain, which locks the phi (ϕ) angle.
- Occupies the smallest area on the Ramachandran plot.
- Commonly found in beta turns and collagen triple helices.
Why Does Proline Have the Smallest Allowed Region?
Unlike other amino acids, proline’s side chain forms a ring that restricts its flexibility:
- Its phi (ϕ) angle is locked around -60°.
- It cannot form α-helices easily and is mostly found in turns and loops.
Implications in Protein Structure
1. Protein Folding and Flexibility
- Glycine: Found in flexible regions like loops.
- L-Alanine: Common in α-helices and β-sheets.
- L-Proline: Introduces kinks in protein structure and stabilizes turns.
2. Collagen Stability
Proline is abundant in collagen because its restricted angles create a rigid triple-helix structure.
3. Secondary Structure Formation
- α-Helices: Prefer alanine; proline disrupts them.
- β-Sheets: Accommodate alanine but not proline.
- Turns and Loops: Favor proline for structural bends.
Conclusion
On a Ramachandran plot, glycine occupies the largest area, L-alanine has a moderate range, and L-proline occupies the smallest region due to its rigid cyclic structure. This plays a vital role in protein folding, flexibility, and function.
37 Comments
Suman bhakar
March 27, 2025👍
Akshay mahawar
April 2, 2025Done 👍
Kabeer
April 6, 2025👍👍
Priyam choudhary
April 24, 2025Ok sir 👍
Neha Yadav
September 25, 2025On a Ramachandran plot, glycine occupies the largest area as it can be plotted anywhere due to no steric hindrance ( small R gp ), L-alanine has a moderate range, and L-proline occupies the smallest region
Aakansha sharma Sharma
September 25, 2025(4) Smallest are would be occupied by L-Proline
Soniya Shekhawat
September 25, 2025Smallest is occupied by L proline due to rigid cyclic structure.
Kirti Agarwal
September 26, 2025Smallest are occupied by L proline due to rigid cyclic structure
Santosh Saini
September 26, 2025On a Ramachandran plot , glycine occupies the largest area, L-alanine has a moderate range and L-proline occupies the smallest region
Neelam Sharma
September 26, 2025Smallest are would be occupied by L-Proline kyu ki esme R grp bhot bda h esley allowed region smallest
Largest allowed region of glycine
Medium region for L alanine
Dharmpal Swami
September 26, 2025L-proline occupy smallest area on ramachandra polt due to its rigid cyclic structure
sakshi vijay
September 26, 2025proline is rigid cyclic structure so it occupy less area in plot
Kavita choudhary
September 26, 2025In Ramachandran plot the glycine can be plotted largest area because of low stearic hindrance and smallest R group L alanin has a moderate rang and L prolin has a smallest rang
Mohd juber Ali
September 26, 2025Stearic hindrance of glycine is very low and glycine occupy any where in ramachandran plot in alanin R group is less so phi and sai value is more so allowed region is largest area
Mohd juber Ali
September 26, 2025Smallest are would be occupied by L-Proline Due to its rigid cyclic structure
Minal Sethi
September 26, 2025Smallest area would be occupied by L-Proline due to larger R group (imino ring)
Muskan Yadav
September 26, 2025Smallest area would be occupied by L-Proline.
Kajal
September 26, 2025L-proline occupies the smallest area due to its large Group
Pallavi Ghangas
September 26, 20254
Priya khandal
September 26, 2025Option 4 is right smallest L proline and medium L alanine and largest glycine
HIMANI FAUJDAR
September 27, 2025Ans On Ramachandran Plot Smallest area occupied by L-Proline due to its rigid cyclic structure and play important role in protein folding, Flexibility and functions.
Khushi Singh
September 27, 2025Proline has smallest allowed region due to which cover smallest area
Aafreen Khan
September 27, 2025Smallest are would be occupied by L-Proline due to its rigid structure. Glycine has largest area plotted anywhere due to small R group
Manisha choudhary
September 28, 2025Proline m imino group hota sbse km allowed region hoga proline k liye glycine m R group hydrogen hota h so glycine plotted anywhere in ramachandran plot steric hindrance nhi hoga
Alanine m methyl side chain hoti h R group
Arushi Saini
September 28, 2025Smallest is occupied by L proline due to rigid cyclic structure.
Mansukh Kapoor
September 28, 2025The correct answer is option 4th
Smallest area would be occupied by L-Proline because it have the imino acid group which locks the phi angle
Sakshi Kanwar
September 28, 2025L-proline due to presence of imino group it’s phi and psi values are more restricted .
Glycine can be plotted anywhere due to smallest R group alanine also have CH3 smallest R group than proline
roopal sharma
September 28, 2025L proline occupies which smallest area due to its NH group.
Avni
September 28, 2025L-proline occupies the smallest region due to its rigid cyclic structure.
Anurag Giri
September 28, 2025L-Proline Most restricted amino acid due to its cyclic imino side chain, which locks phi (ϕ) angle.
Occupies the smallest area on the Ramachandran plot.
Khushi Mehra
September 28, 2025On Ramachandran plot , Glycine occupied maximum area , L – Alanine is restricted due to CH3 group , occupy a region smaller than Glycine
And L-Proline occupied least or smallest area because of its imino side chain.
Heena Mahlawat
September 28, 2025Smallest area occupied by proline due to its cyclic imino side chain
Neeraj Sharma
September 28, 2025Smallest area will be occupied by proline as glyicine will occupy the most and after that l-alanine will cover but proline will cover smallest area compare to glycine and alanine
Divya rani
September 29, 2025L proline occupied smallest area due to its cyclic imino acid side chain it is a most restricted imino acid.
Priyanshi sharma
September 29, 2025L proline occupied the smallest area
Priyanshi Sharma
September 29, 2025Options 4 is correct answer
Pooja
October 5, 2025option 4 is core
Due to rigid cyclic structure