Question

During the translation of mRNA molecules, the new polypeptides are often directed to specific parts of the cell by the presence or absence of short sequences of amino acids called signal peptides. Which of the following would you expect to find in the polypeptides that will eventually fold to become enzymes important in the citric acid cycle? Group of answer choices A. no signal peptide B. an amino terminal signal peptide C.an internal signal peptide D.a signal anchor peptide

Answer 1

Answer:

B. an amino terminal signal peptide

Explanation:

The reactions of the citric acid cycle occur in the matrix of mitochondria. Therefore, all the enzymes required for this pathway are present in the matrix of mitochondria. These enzymes are formed on the ribosomes present in the cytosol and are transported into the mitochondria with the help of cytosolic heat shock proteins. The newly formed mitochondrial proteins have signal sequences present at their N terminal. The proteins to be transported into the matrix have a single signal sequence that at N terminal which is removed by a protease once the enzyme enters into the matrix.