Biology 2382B Lecture Notes - Lecture 20: Membrane Potential, Biological Membrane, Glut2

• School: Western University
• Department: Biology
• Course: Biology 2382B
• Professor: Robert Cumming

Document Summary

Type iv proteins have multiple transmembrane domains and the orientation of each hydrophobic helix of the transmembrane domains depends on the positively-charged residues next to the topogenic sequence. Type iv proteins tend to have alternating sa signal sequences and sta signal sequences, often totalling in 7 transmembrane domains. In type i proteins, the n-terminal signal sequences are always luminal and the sta signal sequence makes up the transmembrane domain. In type ii proteins, positively-charged residues are on the n-terminal side of the sa signal sequence (with protein"s c-terminus in er lumen), while in type iii proteins, positively-charged residues are on the c-terminal side of the. Sa signal sequence (with protein"s n-terminus in er lumen). In type iv proteins, a repeating arrangement of sa and sta signal sequences are present. ), and active transport (atp pumps, antiporters, symporters, etc. Passive diffusion is a form of membrane transport that does not require any membrane proteins.