How many amino acid residues are there for the transmembrane domain?

[TytoAlba95]

Homework Statement

The rise per residue of an alpaha helix is 1.5 Angstrom. A protein spans 4nm bilayer 7 times, through its transmenbrane alpha-helical domain.Aprroximately how many amino acid residues constitute the transmembrane domain of the protein

Relevant Equations

a) 105
b) 450
c) 30
d)190

Ans:d

Total no. of amino acid in each transmembrane domain = 4 nm/ 0.15 nm +1 =27.66
Total no. of amino acids in 7 transmembrane domains = 27.66 x 7 = 193.62 ≈ 190

Hence option d.

Is my approach correct?

 

[Ygggdrasil]

Problem Statement: The rise per residue of an alpaha helix is 1.5 Angstrom. A protein spans 4nm bilayer 7 times, through its transmenbrane alpha-helical domain.Aprroximately how many amino acid residues constitute the transmembrane domain of the protein
Relevant Equations: a) 105
b) 450
c) 30
d)190

Ans:d

Total no. of amino acid in each transmembrane domain = 4 nm/ 0.15 nm +1 =27.66
Total no. of amino acids in 7 transmembrane domains = 27.66 x 7 = 193.62 ≈ 190

Hence option d.

Is my approach correct?

Yes, that looks correct to me.