Figure 1 shows the structure of adenine and thymine. (i) (ii) NH H adenine -H =C thymine Figure 1 Illustrate the potential tautomers of adenine and thymine. Draw a chemical structure of Thyminc-Adenine (T-A) basc pair and label the patterns of hydrogen bond acceptors, donors in the major groove of the TA base pair.

6) Proteins can be modified by phosphorylation, which adds a phosphate group to the hydroxyl group of serine, threonine, or tyrosine residues. The R-group for phosphoserine is shown at right. A) The image below is an Isoelectric focusing strip that shows the unphosphorylated protein-of-interest (in blue). To which side of the unphosphorylated protein would you expect to see the phosphorylated protein? (Draw an arrow to indicate direction). Briefly justify your answer. un-phosphorylatable: Low pH Justify: B) To study the effects of phosphorylation, researchers often mutate a Ser/Thr to appear as though it is always phosphorylated or never phosphorylated at a particular site. What amino acid substitution should you use to preserve similar dimensions as Ser (or Thr) but make the side chain appear to be: constitutively (always) phosphorylated: Justify: Ser or Thr → O O=P-O O I CH₂ Ser or Thr➜ Phosphoserine High pH

Draw the structural formula of the oligopeptide if the amino acids are arginine, glutamine, glycine, methionine and glutamic acid considering the first amino acid is the N-terminus

Hemoglobin is considered to be a tetrameric complex with a 64 kDa (α β)2. When attempting to purify hemoglobin, we must first purify the α and β monomers (about 16 kDa each) to prepare the tetramer. This is formed from the dimer intermediate: 2 α + 2 β -> 2 αβ -> (α β)2. The graph given represents a size-exclusion chromatogram after the refolding of the hemoglobin tetramer Using the size-exclusion chromatogram given, 1.  Draw an SDS-Page Gel with a reducing agent such as BME using the three peaks listed on the graph.