1. 4/2 Objective: Explain the steps and key players in transcription.
DMA: The four types of nucleotides that make up DNA are named for their____________?

2. Transcription

3. RNA: Ribonucleic Acid Monomer- nucleotide
Nucleotide has 3 parts: phosphate, ribose, base
Adenine, cytosine, guanine, and URACIL
Uracil is used instead of thymine in RNA

4. Three kinds of RNA:
1. mRNA – messenger RNA (used in transcription and translation)
2. tRNA – transfer RNA (used in translation)
3. rRNA – ribosomal RNA (folds into a ribosome)

5. Central Dogma of Biology
Genetic information flow in one direction
DNA to RNA to Proteins
1. DNA replication
2. Transcription (DNA to RNA)
3. Translation (RNA to protein)

6. Central Dogma

7. Transcription - The process of using DNA to make RNA.
-Takes place in the nucleus.
- Only copies one gene at a time.

8. Where does Transcription take place in the cell?

9. Key enzymes in transcription:
RNA polymerases- enzymes that bond nucleotides together in a chain to make a new RNA molecule.

10. Transcription Steps Initiation:
A. RNA polymerase finds the Promoter region (start site of the gene)
B. RNA polymerase joins with other proteins to form the transcription complex
C. The transcription complex unwinds the DNA double helix

11. Transcription steps
2. Elongation A. The transcription complex travels down one strand matching RNA nucleotides to the DNA template
B. The strand of growing mRNA hangs off of the complex
C. DNA zips back up as the complex moves.

13. How does the base sequence of the RNA transcript being formed compare with the sequence on the template strand?

14. Transcription Steps 3. Termination: B. Releases the mRNA strand
A. RNA polymerase recognizes when it reaches the end of the gene and the Transcription complex falls off.
B. Releases the mRNA strand
C. DNA zips up, stays intact.
D. mRNA is “packaged” for transport out of the nucleus

15. Results of Transcription:
Single-stranded mRNA
One gene is transcribed at a time
Can be repeated hundreds or thousands of times depending on how much protein is needed.

16. What happens to the Rna transcript after it separates from the dna?