) Describe the role of the signal sequence and the signal recognition particle (SRP) in targeting and processing proteins in the endoplasmic reticulum. 2) What is the function of the trans-Golgi network?

9. Recall that many cells have polarity (as in directionality, in this case). Consider the apical location of a particular protein (A) expressed in epithelial cells, illustrated in the figure above. Which type of defect described below is the most likely to cause the redistribution of that protein around the entire cell? A) A nonfunctional enzyme glycosylase. B) The deletion of a junctional protein. C) The truncation of a protein found in the extracellular matrix. D) A nonfunctional flippase. Answer: Explanation: apical plasma membrane lateral plasma membrane basal plasma membrane basal lamina protein A tight junction

1. Describe the process by which an integral membrane glycoprotein goes from mRNA to being an integral membrane protein 2. Describe in detail the initiation of translation in eukaryotes versus prokaryotes. All steps. 3. Compare and contrast gated transport and transmembrane transport of mitochondria. Specific details are required. 4. Compare and contrast regulation of gene expression between prokaryotes and eukaryotes 5. The plasma membrane, as an example, is described as a fluid mosaic. Why? (hint: LOTS of details)

Which of these answers explains why synaptic vesicles only releasee their neurotransmitter cargo in response to a signal? A) the necessary Rab proteins are not synthesized until an action potential arrives B) vesicle formation at the trans-Golgi network cannot occur in the absence of plasma membrane depolarization C) an additional protein, synaptotagmin, makes vesicle fusion dependent on the calcium concentration D)a plasma membrane transporter is needed to actively pump neurotransmitter into the synaptic cleft. These are inactive until membrane depolarization

The trans-Golgi network is the site of multiple sorting processes as proteins and lipids exit the Golgi complex. Compare and contrast the sorting of proteins to lysosomes with the packaging of proteins into regulated secretory vesicles such as those containing insulin. Compare and contrast the sorting of proteins to the basolateral versus apical cell surfaces in MDCK cells and in hepatocytes.