Question

all please

2. Which of the following is an example of posttranslational modification? a. Glycosylation b. Protcolysis c. Palmitoylation d. All of the above 3. The growing polypeptide chain coming off the ribosomal complex is fairly unstable. It has a tendency to fold back on itself and can aggregate with adjacent polypeptides, and these processes, if allowed to occur, would yield degraded, improperly folded, or large aggregates of nonfunctional proteins. How does the cell prevent this from occurring? 4. Transcriptionally active chromatin, which is called inactive chromatin, which is called , is highly condensed. , is decondensed, while transcriptionally 5. Proteins called act as receptors for cargo protein import into the nucleus, and proteins called play the corresponding role in export from the nucleus. 6. For proteins that normally are nuclear, deletion of the nuclear localization signal and injection of the protein into the cytoplasm of cultured cells will result in localization a. in the nucleus. b. in the cytoplasm. c. in a ring around the outside of the nuclear envelope. d. that is extracellular. 7. The sequence Lys-Asp-Glu-Leu (KDEL) serves to retain proteins in the ER by a. preventing their packaging into vesicles destined for the Golgi. b. binding to receptors within the membranes of the ERGIC and Golgi, which retain them or return them to the ER c. binding the SRP receptor in the ER membrane. d. associating with the lipids in the ER membrane.

Answer 1

Question 2 Answer - (d)

Question 4 Answer - Transcriptionally active chromatin,which is called euchromatin ,is decondensed , while transcriptionally inactive chromatin which is called heterochromatin.