Transcription and RNA Types

Transcription Process

• The process of copying a segment of DNA into RNA is called transcription.
• During transcription, the enzyme helicase breaks the hydrogen bonds between complementary DNA nucleotides.

RNA Molecules

• Messenger RNA (mRNA) is a type of RNA molecule that encodes proteins.
• Messenger RNA (mRNA) comprises only about 5% of total RNA samples.
• Non-coding RNAs (ncRNAs) play a crucial role in transcription, but do not encode proteins.

RNA Synthesis

• The RNA sugar-phosphate backbone is formed during transcription, with assistance from RNA polymerase.
• The primary transcript produced during transcription is a precursor to mature RNA.

Transcription Initiation

• General transcription factors play a crucial role in transcription by recruiting RNA polymerase to the gene promoter.
• RNA polymerase reads the DNA sequence during transcription.

Cellular Compartmentalization

• After transcription, if the cell has a nucleus, the RNA is transported out of the nucleus into the cytoplasm for translation.

DNA Structure

• DNA uses base pairs of nucleotides as a complementary language.
• The process of separating the two strands of the DNA helix during transcription is called helicase-mediated unwinding.

Genome Transcription

• Approximately 90% of the human genome can be transcribed into mRNA.
• About 80% of mammalian genomic DNA can be actively transcribed in one or more types of cells.