Cau 5 : ENZYme noi :

-  Enzyme noi la 1 enzyme noi qua trinh trong tb vi chuc nang cua no la sua chua cac moi lien ket  phosphodiester bi dut gay 1 cach ngau nhien hoac do hau qua cua viec sao chep hoac tai to hop ADN.

- Trong ki thuat ADN tai to hop , no dc dung de han gan nhung cho gian doan trong chuoi duong - phosphat, nhung gian doan nay thuong dien ra khi ADN tai to hop c hinh thanh bang cach noi cac ftu ADN tu cac nguon khac nhau . Vi vay no dc coi la chat keo ftu dc use de ket dinh cac mau ADN voi nhau . Chuc nang nay het suc quan trong doi voi su thanh cong cua nhieu thj nghiem vi vay ADN ligase la enzyme noi chu chot trong cac ki thuat ADN tai to hop.

v > Enzyme fien ma nguoc ( REvese transouptase ) : enzyme fien ma ngc co kha nang tong hop nen ADN 1 mach dc goi la c-ADN ( complemetary DNA ) tu khuon m ARN hoac tu 1 doan polyribonucleotit hoa hoc. Nho enzyme reverse transciptase nay cac nha nghien cuu co the tong hop dc hau nhu bat cu gen rienng biet nao mien co mat mARN cua gen do . Cac C-ADN mach don co the bien thanh mach kep nho ADN polymerase va dc goi la C-ADN kep . Doan C-ADN kep dc gan vao plasmid va bien nap vao vk de tao cac dong c-ADN >