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MAKE CONNECTIONS The polypeptide chain that makes up a tight junction weaves back and forth through the membrane four times, with two extracellular loops, and one loop plus short C-terminal and N-terminal tails in the cytoplasm. Looking at Figure 3.18, whatWhat would you predict about the amino acids making up the tight junction protein?
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- Which of these structures would you expect to find as part of the transmembrane portion of an integral membrane protein? Structure B would be part of the transmembrane domain of an integral membrane protein. Structure C would be part of the transmembrane domain of an integral membrane protein. Structure A would be part of the transmembrane domain of an integral membrane protein.arrow_forwardSuppose that you joined a group of scientists working with a multipass ER-resident membrane protein. By only analyzing the amino acid sequence, how can you determine the number of transmembrane portions that the protein has? How can you determine whether the N- terminus is at the cytosolic side or at the ER lumen side?arrow_forwardn addition to transmembrane a-helices another type of polypeptide structure of Integral membrane proteins that extends through the lipid bilayer is: segments with mainly charged amino acids B barrel segments with mainly polar amino acids single B-strand irregular secondary structure d)arrow_forward
- While investigating structure-function studies in a membrane transport protein, a researcher discovered a single nucleotide mutation that led to the loss of a key alpha-helical segment of the protein in the hydrophilic domain. The mutation that led to this finding is most likely which of the following? Hint: helix breaker O AUC to GUC GAG to CCU GUU to GCU GUG to UUG O CUC to CCCarrow_forwardThe lipid portion of a typical bilayer is about 30 Å thick. (a) Calculate the minimum number of residues in an a-helix required to span this distance. (b) Calculate the minimum number of residues in a B-strand required to span this distance. (c) Explain why a-helices are most commonly observed in transmembrane protein sequences when the distance from one side of a membrane to the other can be spanned by significantly fewer amino acids in a B-strand conformation. (d) The epidermal growth factor receptor has a single transmembrane helix. Find it in this partial sequence: .RGPKIPSIATGMVGALLLLVVALGIGILFMRRRH..arrow_forwardplease help me with this quicklyarrow_forward
- Order following for rate of diffusion through a synthetic lipid bilayer. Explain your order. Cl-, N2, alanine, tRNA, ribose, H2Oarrow_forwardName the three major assumptions made by the "Cell theory". (i) The lipid membrane is composed of lipid molecules. Explain the principle of membrane formation highlighting the role of the physical properties of the lipids. (ii) Comparing dimensions and length scales is often a first step in an analysis. Give an approximate value for the thickness of a lipid bilayer and the linear length of a helical turn of a DNA double helix. A technician wants to amplify DNA from a patient sample. However, the lab is not equipped with a thermocycler. (i) (ii) Name two methods for DNA amplification that can be operated at constant temperature and give their acronyms. Explain these two methods in detail using a schematic and name all necessary components that are required to perform the amplification. Describe the main function of the middle ear. Highlight the role of the ossicles and the tympanic membrane.arrow_forwardUsing the the enzyme acid hydrolase in the lysosome: What is the final destination in which the protein will function? Which features will the protein receive during its manufacture? What is the primary structure (general)? Where is the primary structure made? Where are the secondary and tertiary structures made? Will the protein travel through any organelles during its manufacture? Which ones? What would be the overall result if some part of the manufacture process went wrong, such that the protein ended up as nonfunctional?arrow_forward
- Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax