Consider the events that describe the progress of a protein that will be secreted from the cell. 1. SRP binds to the growing polypeptide chain and to the ribosome. 2. Translation resumes. 3. SRP binds to its receptor. 4. The signal sequence is cleaved. 5. Protein synthesis begins in the cytosol. 6. Translation pauses. A. 5 → 1 → 6 → 3 → 2 → 4 B. 5 → 6 → 1 → 3 → 2 → 4 C. 3 → 6 → 1 → 2 → 4 → 5

the answer is option A. 5 → 1 → 6 → 3 → 2 → 4

Explanation: the events that describe progress of a protein that will be secreted from cell are as follows; Protein synthesis begins in the cytosol,  SRP binds to the growing polypeptide chain and to the ribosome, Translation pauses,  SRP binds to its receptor,   Translation resumes and finally - The signal sequence is cleaved. All these formed the sequence 5 → 1 → 6 → 3 → 2 → 4

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.