Question

Indicate whether each of the following descriptions refers to protein import into mitochondria (M), chloroplasts (C), or both (B). Your answer would be a five-letter string composed of letters M, C, and B only, e.g. BBBMC.

(A ) ATP and GTP hydrolysis drive translocation into the organelle.
( B) The organelle has an extra compartment that requires extra signal sequences for protein targeting.
( C) Transport through the double membrane is driven in part by an H+ gradient across the inner membrane.
( D) Imported precursor proteins have amphiphilic N-terminal signal sequences that are usually removed after use.
(E ) Hsp70 family chaperones inside the organelle assist in protein translocation during import.

Answer 1

The correct associations for the descriptions of protein import are 'BBBBM', which indicate that the first four apply to both mitochondria and chloroplasts, while the last one is specific to mitochondria.

Step-by-step explanation:

The question requires the identification of which descriptions apply to protein import into mitochondria (M), chloroplasts (C), or both (B) organelles. Here are the correct associations for each description:

• (A) ATP and GTP hydrolysis drive translocation into the organelle. - B
• (B) The organelle has an extra compartment that requires extra signal sequences for protein targeting. - B
• (C) Transport through the double membrane is driven in part by an H+ gradient across the inner membrane. - B
• (D) Imported precursor proteins have amphiphilic N-terminal signal sequences that are usually removed after use. - B
• (E) Hsp70 family chaperones inside the organelle assist in protein translocation during import. - M

This results in the answer string being 'BBBBM'.