o Passive transport--passively diffuse >3000-4000 NPC/cell (mammalian); To import about 106 histone/3 mins. (DNA-Sythesizing cell)=100 histone/ min/NPC >Each NPC contains one or more open aqueous channels:9 nm in diameter and 15 nm long The effective size of these channels has been determined by injecting various sizes of colloidal gold particles and examined by electron microscopy. <10 nm in diameter able to enter the nucleus <60kd globular protein❖ Passive transport—passively diffuse ➢3000-4000 NPC/cell(mammalian); To import about 106 histone/3 mins.(DNA-sythesizing cell) = 100 histone/ min/NPC ➢Each NPC contains one or more open aqueous channels: 9 nm in diameter and 15 nm long ➢The effective size of these channels has been determined by injecting various sizes of colloidal gold particles and examined by electron microscopy. <10 nm in diameter <60kd globular protein Able to enter the nucleus