The overall negative charge of the molecule contributes another electron, so ov. Use VSEPR theory (valence shell electron pair repulsion) Boron has 3 valence electrons, and each of the four fluorides contributes one electron to each covalent bond.The shape of the orbitals is trigonal bipyramidal. Two orbitals are arranged along the vertical axis at 90 o from the equatorial orbitals. Three orbitals are arranged around the equator of the molecule with bond angles of 120 o.When you say there is a dipole moment from C-terminus to N-terminus you are thinking of protein as a linear molecule, ignoring the tertiary structure. Like all vectors, dipole moment has direction. sum (vector addition) of all bond dipole moments.
