How do heme levels regulate globin protein synthesis in red blood cells? Answers A - E A Heme responsive inhibitor removes mRNA cap; mRNA degraded B Heme responsive activator increases transciption of globin genes C Heme responsive inhibitor phosphoinactivates elF 2 when heme is low D Heme responsive activator is degraded when heme is low E Heme responsive activator blocks mRNA cap removal; mRNA is not degraded Which of the following post-translational modification contributes to protein stability? Answers A - E A Proline hydroxylation in collagen B Carboxylation of blood clotting proteins C. Methylation of histones D Famesylation of Ras E ADP-ribosylation of a G-protein Use the following alternatives to indicate what signal sequence is found in the protein indicated: Insulin Answers AE A Carboxy terminal tripeptide Ser-Lys-Leu B Signal peptide C (Pro)2-(Lys)4-Ala-Lys-Val D "stop" or "halt" sequence E Mannose-6-phosphate