1. RNA

2. What is it? RNA = ribonucleic acid
Composed of a single strand of RNA nucleotides

3. Three types of RNA Messenger RNA (mRNA)
Carries the message for making proteins from the DNA in the nucleus to the ribosome
3 bases = codon

4. 2. Ribosomal RNA (rRNA)
- The ribosome is made of rRNA and protein.

5. 3. Transfer RNA (tRNA)
- “clover leaf” shape
- found in the
cytoplasm
- carries amino acids
- 3 bases = anti-
codon

6. Transcription Process by which RNA is made from DNA.
Occurs along a segment of DNA.

7. RNA polymerase binds with a promotor region in the DNA.
DNA untwists and unzips in front of the polymerase.

8. 3. mRNA nucleotides are inserted along one side of the DNA molecule
3. mRNA nucleotides are inserted along one side of the DNA molecule. DNA retwists behind the polymerase.
4. RNA polymerase reaches a terminator and the polymerase detaches from the DNA. Pre-mRNA is formed

9. Changes to the pre-mRNA
- An end cap is attached to the 5’ end.
- A poly-A tail is attached to the 3’ end.

10. Introns are removed and exons are spliced together.
Alternative splicing allows cells to use the same gene to make different versions of the same protein