Set up Cornell Notes on pg. 5 Topic: 8.4 Transcription Essential Question :

1. 8.4 Transcription 2.1 Atoms, Ions, and Molecules • Set up Cornell Notes on pg. 5 • Topic: 8.4 Transcription • Essential Question: • What is the central dogma? • Why can an mRNA strand made during transcription, be thought of as a mirror image of the DNA strand from which it was made? • What is the central dogma? • Why can an mRNA strand made during transcription, be thought of as a mirror image of the DNA strand from which it was made? KEY CONCEPT Transcription converts a gene into a single-stranded RNA molecule.

2. The Central Dogma P.4 On Your OWN: • Draw fig 8.10 (pg.239)- color code • Red • Blue • Green • Make a double-bubble map comparing and contrasting DNA and RNA (239-240)

3. rough endoplasmicreticulum Have bumps called ribosomeswhich link amino acids together to form proteins REVIEW:

4. Proteins are used for movement, eyesight, and digestionand practically everything else you do.

5. KEY CONCEPT Transcription converts a gene into a single-stranded RNA molecule. RNA DNA

6. Connect • Suppose you want to play skeeball at a arcade. The game only takes tokens, but you only have quarters. What do you do? • You exchange your quarters for tokens. • In a similar way, your cells cannot make proteins from DNA. • They must convert the DNA into RNA in order to make proteins • This process is known as transcription

7. RNA carries DNA’s instructions. • The central dogma states that information flows in one direction from DNA to RNA to proteins.

8. replication transcription translation • The central dogma includes three processes. • Replication • Copies DNA 2.Transcription • Converts DNA into RNA • RNA is a link between DNA and proteins • “quarters tokens” 3.Translation • Interprets an RNA message into a string of amino acids that will make up a protein

9. Protein Synthesis: the process whereby biological cells generate new proteins. Includes DNA replication, transcription, and translation.

10. Location of Protein Synthesis • Prokaryotic cells: replication, transcription, and translation all occur in the cytoplasm (remember there is no nucleus), at approx the same time • In Eukaryotic cells, where DNA is located inside the nucleus, these processes are separated by location and times. • Replication and transcription occur in the nucleus • Translation occurs in the cytoplasm

11. RNA differs from DNA in three major ways. RNA Ribose Sugar Uracil (U) Single-Stranded DNA Deoxyribose Sugar Thymine (T) Double-Stranded Please add a drawing to each side of your double-bubble map

12. RNA is similar to DNA in a few ways • Both are a chain of nucleotides • Each is made of a sugar, a phosphate group, and a nitrogen containing base • Each has A, C, & G

13. Protein Synthesis Video • Transcription 2m50s

14. Transcriptioncopies specific genes from DNA to make a complementary strand of RNA. • Only a gene, NOT the entire DNA strand is transcribed

15. To transcribe is to make a copy of DNA into a complementary messenger RNA strand

16. Get out 3 Colors and MAKE A KEY on the top of your handout -DNA -RNA - Transcription Complex (RNA Polymerase)

17. transcription complex start site nucleotides 1. RNA polymerase and other proteins, (which we call a transcription complex) recognize the start of a gene and unwind a segment of it.

18. transcription complex start site nucleotides Why must the DNA strands unwind and separate before transcription can take place? • The bases must be exposed so that the DNA can be read

19. DNA RNA polymerase moves along the DNA • 2. RNA polymerase, using the DNA as a template, strings together a “complementary” strand of RNA • Uracil bonds with Adenine U=A (no Thymine) • The DNA helix winds again as the gene is transcribed. RNA

20. DNA RNA polymerase moves along the DNA • How does the base sequence of the RNA transcript being formed compare with the sequence on the template strand? • It is complementary RNA

21. Transcription Practice Transcribe this DNA strand into a mRNA strand *Remember: No Thymine. Instead use Uracil. A=U DNA AAA TAG GAT ATC GGA TAC AGT RNA UUU AUC CUA UAG CCU AUG UCA

22. RNA • 3. The RNA strand detaches from the DNA once the gene is transcribed. • The transcription complex falls apart • DNA re-zips

23. RNA • Where will the RNA transcript go after it separates from the DNA in step 3? • It is processed and LEAVES the nucleus, heads to the cytoplasm

24. Transcription makes three types of RNA. • Messenger RNA (mRNA) which has been transcribed from the DNA, carries the message that will be translated to form a protein. • Ribosomal RNA (rRNA) forms part of ribosomes where proteins are made. • Transfer RNA (tRNA) brings amino acids from the cytoplasm to a ribosome.

25. one gene growing RNA strands DNA Please make a Replication vs. Transcription Double Bubble (bottom of pg. 4) Pg. 242 in book • Transcription and replication are similar, but have different end results. Please create a double-bubble map comparing and contrasting the two processes. • Replication copiesall of the DNA • Transcription copiesa specific gene. • Replication makesone copy (only happens once) • Transcription can make many copies (happens almost continuously)

26. Similarities between DNA replication and Transcription? • Occur within the nucleus • Both are catalyzed by enzymes • Both unwind DNA • “complementary” base pairing • Highly regulated (very carefully done- we want NO mistakes) Differences? • End results are different • Replication makes an identical copy of ALL of the DNA • Happens only once during the cell cycle • Transcription only makes a complementary strand of segments of DNA • Can happen over and over again at anytime

27. Practice DNA A T C G A AA T C G GG A T T RNA UAG C U UUAG C CCUAA