From DNA to protein: replication, transcription and translation

At a glance

• The central dogma: DNA is copied (replication), read into RNA (transcription), processed (capping, splicing, polyadenylation) and decoded into protein (translation).
• The haploid human genome has about 3.1 billion base pairs and about 20,000 protein-coding genes. Coding exons are only about 1.5% of it, which is why an exome is a small fraction of a genome.
• Every step has a variant class that breaks it and a drug or toxin that targets it. Paper 1 questions mostly ask you to connect the two: a nonsense variant and nonsense-mediated decay, a splice variant and exon skipping, rifampicin and RNA polymerase.