Concept explainers
Core Skill: Modeling The goal of this modeling challenge is to propose a model for a transmembrane protein.
Modeling Challenge: As shown in Figure 5.2, some α helices, which are called transmembrane a helices, may be inserted into the hydrophobic region of a membrane and span the entire membrane. Let’s suppose a protein in the plasma membrane has 5 transmembrane α helices. The loops that connect these 5 transmembrane segments are relatively short, except for the one that connects transmembrane segments 4 and 5, which is longer. The amino end projects into the cytosol. Draw a model of this transmembrane protein in the plasma membrane. In your model, draw the transmembrane a helices as cylinders and label them 1 through 5. Also label the amino and carboxyl ends and the cytosol and extracellular environment.
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BIOLOGY
- Select all that apply. This is an image of a plasma membrane, which consists of two layers of phospholipids. The red bubbles are the hydrophilic heads of phospholipids, facing the cell interior and exterior. The yellow strings facing inside of the plasma membrane are the fatty acid tails. Which of the following bonds/interactions do you think could regulate the assembly of the plasma membrane and the adhesion or fatty acid tails to each other? Select all that apply. hydrogen bonds covalent bonds electrostatic forces van der Waals forces hydrophobic force ionic bonds O O 0 0 O 0arrow_forwardMembrane Protein Insertion in the ER This figure displays five small hypothetical proteins. The a-helix secondary structure of the protein is bracketed and the number of amino acids in the helix is indicated. If the hypothetical ER localization sequence is green-yellow-yellow-green-yellow-red, what protein could potentially be a transmembrane protein in the plasma membrane? = Acidic = Basic = Polar (uncharged) O = Hydrophobic CO₂ T 20 CO2 T 20 NH₂ A. T 20 NH₂ B. NH₂ C. T 20 NH₂ D. NH₂ E. tot 10arrow_forwardCreate a ROUGH SKETCH (no need for exact hydropathy indices and residue numbers) of the hydropathy plot for the given membrane protein. -coo Please follow the color assignment of the helical domains and properly label the plot and axes. Here is an example: Amino Outside terminus Transmembrane helices are predicted by hydrophobic stretches of 20-25 aa residues 10 50 100 150 200 250 Hydrophobic Inside Hydrophilic Carboxyl terminus -3 10 50 100 150 200 250 Residue number Bacteriorhodopsin Hydropathy indexarrow_forward
- Question:- How can we determine trans-membrane domains of proteins in the absence of crystal structure?arrow_forwardtled document DO A Sh Edit View Insert Format Tools Add-ons Help Last edit was s.. A P 100% Normal text Verdana 10 ... 4 5 1 I I Spaced practice question: Consider a membrane protein and its chemistry. Which of the following would describe a channel protein? It is an inorganic compound. It is an example of a globular (functional) protein. It is stable when exposed to an acidic environment. It is an example of a fibrous (structural) protein.arrow_forwardI am studying pancreatic islet cells and have isolated, cloned, and sequenced a novel protein that you postulate has 4 transmembrane segments. What kind of experiment would allow me to test this hypothesis that there are 4 trans membrane segments?arrow_forward
- Exercise 1 Summarize the data below obtained from the protein experiments for determination of protein concentration in the form of a graph. Plot a graph containing a title and labels for both of the axis. Three readings were taken for each protein concentration. Find the averages and standard deviations for each reading and plot your graph using Microsoft EXCEL, complete with the error bars. This graph represents will be used to measure the protein concentration in an unknown protein solution. calibration curve for a protein assay (next experiment) where this Concentration of protein (Hg/mL) Absorbance, 595 nm 1 2 3 0.04 0.05 0.03 2 0.12 0.11 0.14 5 0.26 0.25 0.25 10 0.49 0.49 0.51 25 0.82 0.85 0.83 50 1.28 1.24 1.25arrow_forwardProblem: From the following information determine the amino acid sequence of a peptide. N-terminal Edman gives PTH-Alanine C terminal carboxypeptidase treatment, no observable reaction Trypsin cleavage gives three products Arg Peptide containing Ala, Lys Peptide containing Asp, Met, Phe, Pro Mild Chymotrypsin cleavage gives 2 peptides Peptide containing Asp, Pro Peptide containing Ala, Arg, Lys, Met, Phe CNBr cleavage gives 2 peptides Peptide containing Ala, Arg, Lys and homoserine Peptide containing Asp, Phe, Pro You must supply the answer as the 3-letter amino acid sequence from N-terminus to C-terminus in the form (you must use dashes, not spaces between the amino acids) Met-Thr-Glu-Trparrow_forwardProblem: From the following information determine the amino acid sequence of a peptide. N-terminal Edman gives PTH-Alanine C terminal carboxypeptidase treatment, no observable reaction Trypsin cleavage gives three products Arg Peptide containing Ala, Lys Peptide containing Asp, Met, Phe, Pro Mild Chymotrypsin cleavage gives 2 peptides Peptide containing Asp, Pro Peptide containing Ala, Arg, Lys, Met, Phe CNBr cleavage gives 2 peptide Peptide containing Ala, Arg, Lys and homoserine Peptide containing Asp, Phe, Pro You must supply the answer as the 3-letter amino acid sequence from N-terminus to C-terminus in the form (you must use dashes, not spaces between the amino acids)arrow_forward
- Essay question: Compare the 3-D structure of proteins with the 3-D structure of DNAarrow_forwardDescribe the typical principles used to identify topogenic sequences within proteins and how these principles can be used to develop computer algorithms. How does the identification of topogenic sequences lead to prediction of the membrane arrangement of a multipass protein?arrow_forwardRoughly sketch the hydropathy plot for the given hypothetical membrane protein. Follow the color assignment of the helical domains and properly label your plot and axes (NB: Only a rough sketch is being asked. No need be exact with the hydropathy indices and residue numbers). CO-arrow_forward
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage Learning