How does DNA work? Gene: segment of DNA that codes for a protein Problem: DNA cannot leave the nucleus… but proteins are made in ribosomes. SO how do we get from DNA to a protein?! Solution: mRNA (messenger RNA)carries instruction from DNA to the ribosomes so proteins can be made.

The Central Dogma of DNA

DNA RNA

DNARNA Double helixSingle strand (no helix) Deoxyribose sugarRibose sugar A, G, C, ThymineA, G, C, Uracil A = T C = G A = U C = G Differences between DNA & RNA

There are different types of RNA mRNA: messenger RNA tRNA: brings building blocks of proteins (amino acids) to the ribosomes during translation rRNA: makes up ribosomes

1) Transcription Process where mRNA is made from DNA 1.DNA helicase unwinds & unzips DNA 2.RNA Polymerase makes the RNA strand 1 codon at a time Happens in the nucleus

Transcribe DNA to mRNA DNA sequence: T A G A C T C G A A G G C G T mRNA sequence:

2) Translation Using the info in mRNA to make proteins Happens on the ribosomes

CHECKPOINT 1.Draw the Central Dogma of DNA 2.What are 3 differences between DNA and RNA? 3.Where does transcription happen in the cell? 4.What enzyme is used in transcription?

5. Where does transcription start? 6. Where does transcription end? 7. Where does translation happen in the cell?