Question

Statement I: Signal sequence of a polypeptide chain is hydrophobic in nature.
Statement II: Signal receptor particle (SRP) binds tightly to the ribosome that is synthesizing a polypeptide chain with a signal sequence.
Choose the most appropriate answer from the options given below:

• A. Statement I is correct and Statement II is incorrect
• B. Statement II is correct and Statement I is incorrect
• C. Statement I and Statement II both are correct
• D. Statement I and Statement II both are incorrect

Hint:

Signal sequences: hydrophobic.
SRP binds to ribosome with signal sequence.
Directs proteins to the ER.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Signal sequences are used for protein targeting.
They direct proteins to specific cellular compartments.

Step 2: Key Formula or Approach:
No specific formula.
Need to understand protein targeting mechanisms.

Step 3: Detailed Explanation:
Signal sequences are typically hydrophobic.
This hydrophobic nature helps them interact with the signal recognition particle (SRP).
Thus, Statement I is correct.
SRP binds to the ribosome when it synthesizes a protein with a signal sequence.
This binding pauses translation and directs the ribosome to the ER.
Thus, Statement II is also correct.
Therefore, both statements are correct.

Step 4: Final Answer:
Both Statement I and Statement II are correct.
Hence, the correct option is (C).