Following are Fischer projection for a group of five carbon sugars,all of which are aldopentoses. Identify the pairs that are enantiomers and the pairs that are epimers.(The sugar shown herebare not all of the possible five carbon sugars.)

Write a structural formula for a tetrapeptide composed of phenyl-alanine, glycine, aspartic acid, and histidine in which the phenylalanine is N-terminal and the histidine is C-terminal. How many different tetrapeptides could be written that fit the criteria in this question?

Please answer both of the following  1) The Haworth projection of D-altrose is shownWhat type of cyclic sugar is formed? 2)Which of the following statement is true about the quaternary structure of aprotein? only one answer is correct

9L.7

(a) Draw the condensed structural formula, and give the name and abbreviation for the dipeptide Cys-Pro. (b) For the sugar with the structure shown below: (i) draw an arrow pointing to the anomeric carbon (ii) Is this the alpha or Beta anomer? ОН H OH OH OH OH

92.4

Write the name for the trisaccharide depicted below (for example, of the form a - D - xylofuranose). Be sure to include if the sugars are in the pyranose or furanose conformations in the name and include the linkages between sugars (for example, (2 - - > 4)). CH₂OH ОН OH н ОН -CH₂ H\H ОН н н ОН CH2OH н ОН но н н ОН

What are the structural differences between bilirubin and urobilin? (Select all that apply.) O Ring is opened in the first compound, but is not in the second compound. Several methylene bridges are reduced in the second compound. O Iron atom is absent in the second compound, but is present in the first compound. The central methylene bridge is reduced in the second compound, but is not in the first compound. O Ring is opened in the second compound, but is not in the first compound. Some vinyl groups are reduced into ethyl groups in the second compound. The central methylene bridge is oxidised in the second compound, but is not in the first compound. O Some vinyl groups are reduced into ethyl groups in the first compound.

Draw the four stereoisomers of threonine as Fischer projections.

Draw both possible disaccharides of D-psicose and D-mannose that are joined by an α(1→4) glycosidic linkage. Are either of them now a reducing sugar?