Nuclear envelope Flashcards
the nuclear envelope is composed of two membranes
inner membrane
outer membrane
perinuclear space
how many nuclear pores are in a mammalian nucleus?
3,000-4,000 pores
10-20 pores per mm2
what is the structure of the nuclear pore?
elaborate structure of about 100 proteins
120 nm diameter
octagonal arrangement
what pass through nuclear pores?
small water soluble molecules
how do larger molecules pass through nuclear pores?
by approval with a transporter.
what is simple diffusion?
small molecules diffuse through aqueous diffusion channels
what is active transport?
larger molecules travel through transporters at the center of the nuclear pore complex
what does import through nuclear pores require?
nuclear localization signal, importin, and GTP hydrolysis
what does export out of the nuclear pores require?
nuclear export signal, exportin, and GTP
