Zinc fingers are DNA binding motifs. Its molecules is made up of c2h2 (two cysteines two histidines) attached to one zinc in the centre. ZFNs are engineered endonucleases that targets specific sites in DNA and switch it off by inhibiting it's transcription machinery.
+Kareem Farouk Lancaster university. I was as part of my course doing DNA technology. The lecturer did not explain it that well and it took me a while of working out and looking for the best way to understand it.
The class of drugs that Levitra, Viagra, Stendra, and Cialis belong to are called PDE5 inhibitors. They work by relaxing tight blood vessels, allowing more blood to surge into the penis and cause an erection, says Gregory Bales, M.D., an associate professor of urology at the University of Chicago.
The little pills do the trick for more than two-thirds of men with Viagra protects the heart (ED). They also work for guys who simply need them for a short time to get their “confidence back,” says Michael Eisenberg, M.D., director of male reproductive medicine and surgery at Stanford University.