1. Replication, Transcription and Translation
Biology
Powerpoint #2 – Chapter 12
Mr. Velekei

2. Vocabulary
DNA Polymerase
DNA Replication
Semi-Conservative

3. Warm Up: Base Pairing 1.
A C C T G A 2.
G C T A
G A G

4. 3. Describe what a double helix would look like untwisted:
Ladder, with bases for steps

5. 4. What is the DNA ‘backbone’ made of?
Phosphorous
and Sugar

6. DNA Replication Nucleotide Hydrogen bonds Sugar-phosphate backbone Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)

7. 1. What is DNA replication?
Making a copy of DNA
DNA replication is when DNA polymerase (an enzyme) opens the DNA molecule and matches complimentary bases to each base.

8. Mitosis with Replication2 2 2
Makes 2 Identical Cells

9. Mitosis without Replication1 2 1
Makes 2 Different cells with
half as much DNA

10. 3. Why is DNA replication important for cells and multicellular organisms?
Replication allows cells to divide Forming cells that are genetically identical to the original

11. DNA Replication Original strand New strand Growth Replication fork
DNA polymerase
New strand
Original strand
Nitrogenous bases

12. 4. When does DNA Replication occur?
After the cell grows big enough to divide, during interphase, the “S” phase

13. 5. What is a chromosome?
A chromosome is DNA that is twisted up very tightly around histones

14. 6. What is DNA Polymerase?
Principal enzyme in DNA replication; adds nucleotides to growing strand of DNA and proofreads new strand of DNA

15. 7. Draw a picture of a Chromosome before and after DNA replication

16. 8. Drawings of the 3 steps of DNA Replication
DNA Polymerase

17. 9. Explain why DNA replication is considered ‘semi-conservative?
In the new DNA created, one strand is from the original, and one is a new one.
Semi = part of
Conserve = save

18. Biology Powerpoint #2 – Chapter 12 Mr. Velekei
Transcription
Biology
Powerpoint #2 – Chapter 12
Mr. Velekei

19. Vocabulary
Exon
Intron
RNA Polymerase
Transcription
Uracil

20. RNA Where is DNA stored? ______________________ Nucleus
What organelle makes proteins? ______________________
Where are proteins made? ______________________
Nucleus
Ribosomes
Cytoplasm

21. What problem might this pose?
DNA can not take directions for making proteins to the ribosomes.

22. How does RNA solve this problem?
RNA is a disposable copy of DNA that can leave the nucleus

23. RNA has ribose sugar instead of deoxyribose
B. RNA’s structure is very similar to the structure of DNA except for 3 major differences:
RNA has ribose sugar instead of deoxyribose

24. 2. RNA is single-stranded
3. RNA has uracil (U) instead of thymine (T)
DNA: AGTCCTTTAGT
RNA: AGUCCUUUAGU

25. There are three main types of RNA:

26. 1. Ribosomal RNA (rRNA)

27. 2. Transfer RNA (tRNA)

28. 3. Messenger RNA (mRNA)

29. III. Transcription
Transcription: Producing RNA by copying part of the DNA’s nucleotide sequence
RNA
DNA
RNA polymerase
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)

30. Describe the process of transcription using drawings.
RNA Polymerase rips open the DNA double helix
RNA polymerase grabs bases and lines them up with the original DNA strand
Half of the DNA is copied into a strand of mRNA, then the DNA strand closes, hydrogen bonds reform

31. How does RNA polymerase know where to start?
Starts when it finds a “promoter”
(specific base sequence)
Found near the beginning of a gene sequence

32. Describe the process of RNA editing
RNA editing is a process that occurs in the nucleus.
It removes introns “intervening sequences” and leaves mRNA with only the exons “expressed sequences.”
After editing a cap and tail are attached and the mRNA is ready to enter into the cytoplasm.

34. Biology Powerpoint #2 – Chapter 12 Mr. Velekei
Translation
Biology
Powerpoint #2 – Chapter 12
Mr. Velekei

35. Vocabulary
Anticodon
‘AUG’
Codon
Polypeptide
‘Stop’ Codon
Translation

36. IV. Translation
Proteins are long chains of amino acids.
Codon: 3 consecutive nucleotides that “code” for a specific amino acid.
What is the universal “start” codon:
AUG
What are the three “stop” codons?
UGA, UAA, UAG

37. The Genetic Code

38. The Genetic Code

40. Use the genetic code below to translate the following mRNA sequences:
A U G U A A C G G G C A U U U U A A
U C C A U G G A A G U G A U U C C A U A A
C C A U G U G U C C C C A A U G A A A A

41. Use the genetic code below to translate the following mRNA sequences:
A U G U A U C G G G C A U U U U A A
U C C A U G G A A G U G A U U C C A U A A
C C A U G U G U C C C C A A U G A A A A
Methionine (START), Tyrosine, Arginine, Alanine, Phenylalanine, STOP.
Serine, Methionine, Glutamic Acid, Valine, Isoleucine, Proline, STOP
Methionine, Cysteine, Proline, Glutamine, STOP, Lysine

42. Translation:
The decoding of RNA into a polypeptide chain (protein)

44. The Central Dogma of Biology is:
DNA  RNA  protein
Where does the first step take place? Nucleus
Where does the second step take place? Cytoplasm

45. What is the job of tRNA during translation
What is the job of tRNA during translation? Bringing amino acids to the ribosomes and match them up with the correct base on mRNA.
What is an anticodon? The three bases on a tRNA that match with the mRNA codons.
What is the role of the ribosome during translation? It is the site of protein assembly

47. H. 1) mRNA is transcribed in the nucleus then travels to the cytoplasm

48. 2) Ribosome grabs mRNA. tRNA brings amino acids to the ribosome

49. 3) tRNA matches with complimentary mRNA
3) tRNA matches with complimentary mRNA. Ribosome makes peptide bond between amino acids, and breaks the bond between tRNA and amino acid.

50. 4) Peptide chain continues to grow until ribosome reaches a stop codon Protein is complete.