After today you will be able to Explain how insulin producing cells are like dysfunctional factories when a person is diabetic Interpret experiments about protein production and make conclusions about why protein production is impaired Does someone in your family siblings parents or grandparents have diabetes No Yes A pancreatic cell with radioactively labeled insulin What conclusions can you make about insulin Insulin secretion a model for protein secretion RER NUCLEUS DNA vesicles Golgi ribosome mRNA Insulin protein Plasma membrane Nuclear pores exocytosis Cells take up glucose if insulin is available http www vivo colostate edu hbooks pathphys en docrine pancreas insulin phys html See animation here Muscle and liver cells that take up more glucose then they need can store it as glycogen stained red inside cells http masteringbiology com Bioflix videos and other useful tools TTQ typical test question Which situation would lead to hyperglycemia 1 A loss of insulin receptors 2 Too much insulin 3 Destruction of insulin producing pancreatic cells Learning catalytics TTQ Which situation would lead to hyperglycemia 1 A loss of insulin receptors 2 Too much insulin 3 Destruction of insulin producing pancreatic cells The CFTR protein normally functions in various cells attached to the plasma membrane allowing chloride ion transport A defective CFTR gene defective CFTR protein What is the cause of cystic fibrosis Hypothesis 1 No CFTR protein is produced and thus there is no function Hypothesis 2 Lung cells produce CFTR but the CFTR is misfolded on the plasma membrane and thus the protein doesn t function Hypothesis 3 Lung cells produce CFTR but it cannot be successfully exported from the cell thus there is no CFTR on the plasma membrane of lung cells Sample type Protein size Normal 175 KDa Normal 175 KDa Normal 175 KDa CF 160 KDa CF 160 KDa CF 160 KDa What can we conclude about the CFTR protein from these data Can you reject any hypotheses yet Hypothesis 1 No CFTR protein is produced and thus there is no function Hypothesis 2 Lung cells produce CFTR but the CFTR is misfolded on the plasma membrane and thus the protein doesn t function Hypothesis 3 Lung cells produce CFTR but it cannot be successfully exported from the cell thus there is no CFTR on the plasma membrane of lung cells Learning catalytics which hypothesis is supported by these data Lung tissue comparison Plasma membrane Plasma membrane Plasma membrane Plasma membrane Plasma membrane Plasma membrane CFTR protein is selectively stained so as to compare normal NL vs cystic fibrosis CF patients Other boxes are controls to show the structure of the tissues first column and to show that other proteins in CF patients are not affected last column Hypothesis 1 No CFTR protein is produced and thus there is no function Hypothesis 2 Lung cells produce CFTR but the CFTR is misfolded on the plasma membrane and thus the protein doesn t function Hypothesis 3 Lung cells produce CFTR but it cannot be successfully exported from the cell thus there is no CFTR on the plasma membrane of lung cells Which hypothesis is supported by these data Inner Life of the Cell http multimedia mcb harvard edu http www xvivo net the inner lifeof the cell