Change the rendering style for the Nucleotide backbone to Wire.ī. Now, we are going to remove the hydrogens to get a better view of the sugar phosphate backbone.Ī. Open the Style menu and select Edit Global Style. Which of the groups listed above gives DNA its negative charge?ġ4. a 3' hydroxyl (OH) group at the end of a DNA strandġ2. The sugar phosphate backbone has sugar rings, each with 5 carbons and an oxygen, that are held together by phosphodiester bonds.įind, circle, and label examples of each of the chemical groups or atoms, listed below.ĭ. Compare the sketch of double-stranded DNA (at the end of your worksheet handout), in the DNA worksheet, to the structure shown in Cn3D. Click the pointer in the Sequence/Alignment Viewer window to deselect the sequence and see it colored by element.ġ1. Open the Select menu and choose Show Selected Residues.ġ0. To do this, use the pointer to select all of the bases in either strand of DNA in the Sequence/Alignment Viewer window.ĩ. What charge do the phosphate groups give to the outside of the DNA molecule?Ĩ. Notice where the phosphate groups are located. If you've moved the DNA structure, turn it back again so that you’re looking through the center. The DNA backbone is referred to as the 'sugar-phosphate' backbone because it contains deoxyribose groups (the sugars), held together with phosphodiester bonds (each phosphodiester bond contains one phosphate group).ħ. Only the backbones of the two DNA strands are visible now. Select Rendering Shortcuts > Toggle Sidechains. To see the backbone structures more clearly, remove the bases. Which element appears in the center, but not in the backbone?Ħ. Which element appears in the backbone, but not in the bases?ī. Look at the colors, and use your color key, from the DNA building block activity, to locate the different elements.Ī. Turn the DNA so that you're viewing it from one end with the backbone along the outside and the bases in the center. The backbone for each DNA strand now appears on the outside of the DNA, with the bases in the middle. Make sure that the box in the Show column is checked.ĥ. Change the settings for the Nucleotide sidechains to show Space Fill and Element (The pull-down menu in the image on the right shows 'Molecule.' this should be changed to element). Change the settings for the Nucleotide backbone to show: Complete, Ball and Stick, and Element, as shown in the Style Options window above.ģ. To see the backbones more clearly, open the Style menu. The backbone of each DNA strand is made of sugar residues that are held together with phosphodiester bonds. The DNA backbone and the double-strand DNA drawingġ. In this activity, you will explore features of the backbone and learn about the bonds that hold nucleotides together. The chemical elements in the backbone are responsible for many of the physical properties of DNA, such as charge and strength. Nucleotides within a DNA strand are joined together by strong covalent bonds located in the DNA backbone.

Backbone of dna