Within a naturally-occurring polypeptide, under neutral pH conditions (pH = 7.0), which of the following amino acids always has a positively charged amine group? (Choose one answer)  the first amino acid in the primary structure histidine lysine arginine the last amino acid in the primary structure

You will now build a 15 amino acid peptide using another paper or wire backbone as you did above.  You will pick 15 amino acids, matching the criteria below, and put them onto your backbone about 3 inches apart.  This will be the primary structure of your novel protein.  Select  15 amino acids that meet the following criteria 6 hydrophobic R groups 2 acidic R groups 2 basic R groups 2 cysteine R groups 3 hydrophilic R groups  Place the R groups in any order you choose on your paper or wire backbone as you did above. Start at the N-terminus and place each R group about 3 inches apart until all 15 are attached to the mini toolbar. You have just built the primary structure of your protein.     Question 1:  Record the sequence of amino acids in your protein, starting with the N-terminus.  The N-terminus is the end of the polypeptide that has a free nitrogen group.  The C-terminus, or carboxyl end, will have a free carboxyl group. You can use the three letter amino acid abbreviation to…

Draw the structure of the tetrapeptide MIEL. Refer to the slide sets for the structures of the amino acids. Encircle all the peptide bonds. Box and label the N- and C-terminal amino acid residues.

In the peptide shown below, a covalent bond that could rotate to form secondary structure is correctly identified / labeled by letter: A B OH still fot D OB OC O O O B D F C OA HN E NH OH "NH₂ - F