1. RNA

2. RNA RNA = RiboNucleic Acid Structural units = nucleotides
Nucleotide – 3 part:
A sugar – ribose
A phosphate group
A nitrogen base

3. RNA Nitrogen Bases – name source for the nucleotides A = adenine
U = uracil
C = cytosine
G = guanine

4. RNA Types
3 types of RNA:
Messenger RNA (mRNA) – carries genetic information from DNA in nucleus to ribosome; three base sequence called a codon
Ribosomal RNA (rRNA)- makes up ribosomes, where protein is made
Transfer RNA (tRNA)- transfers amino acids from the cytoplasm to the ribosome; its three base sequence is called an anitcodon

5. Differences between… DNA & RNA
Deoxyribose Sugar
2 strands
Thymine
Remains in nucleus
Ribose Sugar
1 strand
Uracil
Can leave nucelus

6. Transcription

7. Transcription
DNA  mRNA (occurs in the nucleus)
a. The complementary strand of RNA is built by the enzyme RNA Polymerase
RNA polymerase binds to & separates the DNA strands at promoter sites
Promoter - 3 base sequence that serves as a starting and ending points for RNA to be made

8. Transcription
RNA polymerase uses one strand of DNA as a template to make the complementary strand of mRNA

9. DNA contains…
Introns – nucleotide sequences that do NOT code for proteins
Exons – nucleotide sequences that do code for proteins

10. RNA polymerase copies both introns and exons, but before mRNA leaves the nucleus…
Introns are cut out of the sequence
Exons are spliced (glued) back together to form the final mRNA

11. mRNA travels to the ribosomes (outside of nucleus)