Question

The rise per residue of alpha helix is about 1.5A. A protein spans 4 nm bilayer 7 times through its transmembrane alpha-helical domain. Approximately, how many amino acids residues constitute the transmembrane domain of the protein? Explain

Answer 1

it means that the rise of the alpha helix and is about 1.5a and a protein spans bilayer.    1.5*1.2 [because bilayer=1.2]
         4*7=28nm
nm=nano metre

Answer 2

4nm bilayer,7 timeso through transmembrane protein.

7×4=28

28 is the length of protein.

To find residues...28/1.5=186 nearly..190

(1.5=rise of residue )given.

Ans.190 aminoacid residues