Step 1: Understanding Aspartame
Aspartame is a dipeptide formed by the condensation of aspartic acid and phenylalanine. The methyl ester group is added to the carboxyl group of the phenylalanine residue.
Step 2: Structural Features of Aspartame
Step 3: Verifying the Structure
Structure (B) correctly shows the peptide bond between aspartic acid and phenylalanine, with the methyl ester group on phenylalanine.
Conclusion
The correct structure of aspartame is represented by option (B).
To solve the problem, we need to determine the correct structure of aspartame, which is a dipeptide consisting of aspartyl phenylalanine methyl ester.
1. Understanding the Components:
Aspartame is made from aspartic acid and phenylalanine, with the phenylalanine part esterified as a methyl ester.
- Aspartic acid has two carboxyl groups, one of which forms a peptide bond.
- Phenylalanine contains a phenyl (Ph) group attached to the alpha carbon.
2. Structure of Aspartame:
- The amino group of phenylalanine bonds with the carboxyl group of aspartic acid.
- The free carboxyl group of phenylalanine is converted to methyl ester (–COOCH₃).
- The resulting structure is a dipeptide: aspartyl-phenylalanine methyl ester.
3. Identifying the Correct Option:
Among the given options, option (B) correctly shows:
- Aspartic acid with free amino and carboxyl groups.
- Phenylalanine linked via peptide bond.
- Methyl ester group at the carboxyl terminal of phenylalanine.
Thus, option (B) is the correct structure of aspartame.
Final Answer:
Option (B)
List-I (Hormones) | List-II (Functions) |
---|---|
A) Glucocorticoids | I) Control the carbohydrate metabolism |
B) Mineralocorticoids | III) Control the level of excretion of water and salt by the kidneys |
C) Progesterone | II) Prepares the uterus for implantation of fertilised egg |
D) Estradiol | IV) In the control of menstrual cycle |
Two identical concave mirrors each of focal length $ f $ are facing each other as shown. A glass slab of thickness $ t $ and refractive index $ n_0 $ is placed equidistant from both mirrors on the principal axis. A monochromatic point source $ S $ is placed at the center of the slab. For the image to be formed on $ S $ itself, which of the following distances between the two mirrors is/are correct: