1. DNA-RNA-Protein The Central Dogma

2. Transcription-1 DNA can’t leave the nucleus. Proteins are made in the cytoplasm. What a conundrum!

3. Transcription-2 A copy is made The copy is RNA Almost the same as DNA…but not. – Single stranded – Uracil instead of thymine – Ribose sugar instead of deoxyribose.

4. Transcription-3 The copy is made by base pairing – A-U – G-C RNA polymerase binds to DNA and separates the DNA strands RNA polymerase uses one strand of DNA as a template from which nucleotides are assembled into a strand of RNA.

5. Transcription -4 This RNA is called mRNA for messenger RNA. It carries the message

6. Translation Making a protein using the mRNA strand. Done by the ribosome. Problem: What is the ribosome made of?

7. Ribosome Made of rRNA and Protein Made in the nucleolus rRNA is transcribed here so no problem. What about the protein? Where is protein made? In the cytoplasm by the ribosome. The needed proteins are imported into the nucleus to build the ribosomes.

8. Back to Translation The mRNA leaves the nucleus through holes in the nuclear envelope. The two subunits of the ribosome come together around the mRNA. The mRNA is read by the ribosome in sets of 3 called a codon.

9. tRNA Different types of tRNA carry different amino acids. They have a three nucleotide sequence called an anticodon. The amino acids are joined together in order according to the codons on the mRNA. TaDa! Protein made according to instructions on the DNA.