BIOL 200 Lecture Notes - Lecture 7: Cytosol, Ribosomal Rna, Chloroplast
Document Summary
Biol 200 lecture oct 6 iclicker q: polar and charged molecules (~7-8nm in size) require specific transporters to get into the nucleus. Everything that goes in/out of nuclear membrane goes through nuclear pore complex (npc). Two mechanisms for nuclear transport: diffusion (passive) Ions and small molecules (up ~9nm max. in diameter) can diffuse freely and non- selectively through through the npc: active transport. Energy required transport large molecules (larger moelecule (>9mm) into nucleus in selective manner. Only proteins containing special amino amid sequence. (nls or localisation signal) nes (nuclear export signal), are recognized by nuclear transport of receptors (import and exportins) and directed into and out of cell, B so(cid:373)ethi(cid:374)g that (cid:449)as(cid:374)"t a(cid:271)le to pass nuclear membrane. Always compare graphs together: on the envelope, the rest = what it looks like inside. If there is no targeting sequence on the protein in cytosol, then the protein stays in the cytosol. Ribosomal subunits assembled in nucleolus/nucleus (where rrna is being transcribed)
