I need help with this question!

4. Look up the published structures of the enzyme flippase (use PDB ID 6NCJ). Note that there are ions in the crystal structure as well as fatty acid-like molecules-the ions used to grow the crystal, and are not important for protein function. a. What is the most abundant secondary structural element in this structure? b. How many fatty-acid like molecules are in this structure? c. What is the first amino acid encountered at the amino terminus of the protein (hint: coloring residue property by sequence ID starts with blue at the N-terminus and goes through the rainbow to red at the C-terminus)? d. Are the N-terminus and C-terminus of the protein located on the same side or opposite sides of the protein? Remember to rotate the structure before answering! e. View the model in a space-fill format. Are there any pockets or cavities on the surface of the structure? If no, why not? If yes, why is this needed? f. How many subunits are in this structure