Bell Ringer: What is a gene? I’m not talking about the ones you wore to school either!
RNA and Step 1 of protein synthesis RNA & TRANSCRIPTION
What is a Gene? Genes are sections of DNA that are instructions that control the production of proteins.
What is a Gene?
Central Dogma Proteins DNA RNA Transcription Translation Step 1 Step 2 Occurs at the Ribosome Occurs in the Nucleus
Protein Synthesis Consists of 2 main steps Step 1: Transcription Step 2: Translation
Transcription Step 1 DNA RNA Occurs in the Nucleus
RNA is different from DNA in 3 ways What is RNA? RNA is different from DNA in 3 ways
The sugar is Ribose instead of deoxyribose
RNA is Single stranded instead of double stranded
G C C G T A A U Thymine is replaced by Uracil Let’s make an RNA strand How to code DNA into mRNA In RNA There is no Thymine Adanine bonds to Uracil A – U G C C G Uracil Adenine T A Let’s make an RNA strand DNA A T G C mRNA A U U A C G U G
You just did TRANSCRIPTION!!! Let’s Practice some more!! DNA A T G C mRNA U A C U G G G U C C U DNA T C A G mRNA A A G U G U C U U A G C U
What is Transcription? This is the stage where the RNA is made from a strand of DNA using the enzyme RNA polymerase. This occurs in the nucleus of the eukaryotic cell.
Why is Transcription important? Because DNA is too big to leave the nucleus, the cell needs to make a messenger that will take the genetic code of DNA from the nucleus to the protein factories (ribosomes) in the cytoplasm.
What happens during Transcription? An Enzyme called RNA polymerase binds to one strand of the DNA at the start codon.
What happens during Transcription? RNA polymerase will unwind the DNA helix and separate the 2 strands. RNA polymerase moves along the DNA strand, reading the bases and making an mRNA strand.
What happens during Transcription? The RNA polymerase detaches when it hits a stop codon. The DNA then rewinds itself back into a helix