Extracted text: * hat do you think holds together the various secondary structural elements in a Particular three-dimensional pattern? (Hint: Look back at Figure 4 - what is sticking out from the sides of the a-helices and B-strands?) glutamic acid B CH, CH valine CH H-N CH H. valine alanine CH2 CH2 lysine Figure 4-4 Essential Cell Biology 3/e (O Garland Science 2010) Figure 6. Three examples of bonding interactions that stabilize the tertiary structures of proteins (indicated by arrows A, B,and C). Copyright 2013 from Essential Cell Biology, 4th Edition by Alberts et al. Reproduced by permission Garland Science/ Taylor & Francis LLC. CH2 CH, SH SH CH2 CH2 OXIDATION CH2 SH REDUCTION SH CH2 CH2 Figure 4-26 Essential Cell Bialogy 3e o Garland Science 2010) Figure 7. Disulfide bonds within proteins can form (left-pointing arrow) or be broken (right- pointing arrow), depending on their chemical surroundings (oxidative or reducing). Copyright 2013 from Essential Cell Biology,4th Edition by Alberts et al. Reproduced by permission of Garland Science/ Taylor & Francis LLC.
Extracted text: Figure 7 shows one additional type of bond that can stabilize the tertiary structure of a protein. This bond is called a disulfide bond (or disulfide bridge), and it involves the sulfhydryl (-SH) R groups from one particular type of amino acid. A disulfide bond can form only under certain conditions (oxidative conditions). We'll talk about oxidation and reduction next week. For now, just note that this type of bond does exist in some proteins. Answer the below questions on tertiary structure in your own document. 8. Figure 6 shows examples of bonds that might stabilize the tertiary structure of a protein (labeled A, B, and C). Do these interactions involve only the amino acid R groups, only the polypeptide backbone atoms, or both? 9. In the table below, indicate what type of bond/ interaction is represented in the examples shown in Figure 6, panels A, B, and C and whether each interaction involves group or backbone atoms. Example Type of Bonding Interaction R group or backbone? B C 10. For each of the three interactions shown in Figure 6, indicate how changes in the following conditions might affect those interactions: pH, temperature, salt concentration. Explain your answer. 11. Which amino acid can form disulfide bonds? To help you answer, refer to amino acid chart and Figure 7. 12. What is different about the disulfide bond compared to the other types of bonds that stabilize tertiary structure? Based on your existing knowledge of bonding, is this bond weaker or stronger than the other types of bonds that stabilize tertiary structure? 13. Make a prediction of which tertiary interactions you might be more likely to find in the proteins of prokaryotic species that live in the extreme environment of hot springs compared to similar species that live in more moderate environments. Explain your answer.