1. TRANSCRIPTION VERSUS TRANSLATION
DNA VERSUS RNA
TRANSCRIPTION VERSUS TRANSLATION

2. Michigan Benchmarks B4.2x DNA, RNA and Protein Synthesis
B4.2g Describe the process of replication, transcription, and how they relate to each other in molecular biology.

6. Two Types of Nucleic Acids:
DNA—Deoxyribonucleic Acid
Set of directions for the cell
RNA—Ribonucleic Acid
Involved with protein synthesis

7. Proteins Review of proteins:
Building blocks—amino acids (20) different types

8. Function of Proteins— Enzymes—speed up chemical reactions
Structures—muscle, teeth, hair, skin, bones, organs
Hormones—insulin, estrogen, testosterone

9. Type of protein
The arrangement of hundreds of amino acids determines type of protein;
The type of protein in a cell determines the kind of cell it is and its function.

10. RNA Structure— Ribonucleic acid
Molecule that carries out the “instructions” coded in DNA
DNA-original
RNA-copy
Composed of nucleotides—building blocks

11. Review/Explain: Types of Nucleic Acids
What are the two types of nuclei acids?
Ribonucleic Acid
(RNA) – Single Stranded
Deoxyribonucleic Acid
(DNA)
Double Helix
(Twisted Ladder)

12. RNA Ribonucleic Acid (RNA) Sugar + Phosphate Backbone Differs from DNA
Single Stranded
Ribose Sugar
Base Pairs A-U, G-C
Are there T’s in RNA?
A, U no T’s in RNA
RNA assists DNA in manufacturing needed proteins

13. RNA Versus DNA: Different from DNA in 4 ways— So DNA= TAG Then RNA=AUC
Sugar in RNA is ribose (DNA-Deoxyribose)
Single-stranded (DNA—double stranded)
Has uracil as a base instead of thymine
So DNA= TAG
Then RNA=AUC

14. Practice
On your paper, complete the missing DNA strand by adding the complementary bases.
A T C G T T G C C A T C
T A G C A A C G G T A G
Make the complementary RNA strand for the single strand of DNA below:
A A T C A T C A C G T T
U U A G U A G U G C A A

15. RNA occurs in 3 Different forms:
1.mRNA—messenger RNA (transcription); carries the “blue print” for a particular protein out of nucleus to a site on ribosome
2. tRNA—transfer RNA; attaches to amino acids and carries it to ribosomes (translation)
3. rRNA—ribosomal RNA
--makes up part of the ribosome
--believed to bond amino acids to form protein chain

16. --RNA polymerase—enzyme that binds to a region in DNA (promoter) – this unwinds the DNA double helix and seperates a section into two strands

17. Major players in transcription
RNA polymerase- complex of enzymes with 2 functions:
Unwind DNA sequence
Produce primary transcript by stringing together the chain of RNA nucleotides

18. Major players in transcription
mRNA- type of RNA that encodes information for the synthesis of proteins and carries it to a ribosome from the nucleus

19. Transcription RNA forms base pairs with DNA
C-G
A-U
Primary transcript- length of RNA that results from the process of transcription

20. TRANSCRIPTION
ACGATACCCTGACGAGCGTTAGCTATCG
UGC
UAU
GGG
ACU

21. Transcription Graphics

22. Only one side of the DNA double helix is transcribed, called the leading strand (the other side is the lagging strand)

23. Transcription Graphics

24. Reminder: DNA A-T; G-C
RNA A-U; G-C
Pairing begins with that sense strand to form RNA strand

25. DNA strand CGATG paired GCTAC
*RNA strand GCUAC
Bonding of the RNA strand together is next step. RNA nucleotide phosphate bonds to sugar (ribose) of another RNA nucleotide

26. Bonding continues until terminator on the DNA strand is met;
Terminator- codes for the end of a protein
Separation of RNA strand from DNA strand 

27. mRNA Processing Primary transcript is not mature mRNA
DNA sequence has coding regions (exons) and non-coding regions (introns)
Introns must be removed before primary transcript is mRNA and can leave nucleus

28. Transcription is done…what now?
Now we have mature mRNA transcribed from the cell’s DNA. It is leaving the nucleus through a nuclear pore. Once in the cytoplasm, it finds a ribosome so that translation can begin.
We know how mRNA is made, but how do we “read” the code?

29. How the Codes Work How the Code Works
In DNA—triplet codes for an amino acid; mRNA carries the code for amino acids in groups of 3 nucleotides 

30. Codons
Codon—the nucleotide sequence in mRNA that codes for a specific amino acid
Ex) GUC~forms amino acid valine
Codons are like three letter words
Note: several codons may code for same amino acids

31. Initiation Codon—a codon that signals the beginning of a protein; AUG (Methionine)
DNA genetic code is almost universal… a given codon codes for the same amino acid in different organisms
(some exceptions include mitochondrial DNA)

32. The Genetic Code

33. Reading the DNA code Every 3 DNA bases pairs with 3 mRNA bases
Every group of 3 mRNA bases encodes a single amino acid
Codon- coding triplet of mRNA bases

34. ACGATACCCTGACGAGCGTTAGCTATCG
UGC
UAU
GGG
ACUG

35. Translation
Second stage of protein production
mRNA is on a ribosome

36. Translation Building proteins molecules by mRNA code
Involves ribosomal RNA (rRNA)
tRNA take free floating amino acids, not randomly
Anticodon—determines which amino acids the tRNA will carry

37. Translation Second stage of protein production mRNA is on a ribosome
tRNA brings amino acids to the ribosome

38. Transcription vs. Translation Review
Process by which genetic information encoded in DNA is copied onto messenger RNA
Occurs in the nucleus
DNA mRNA
Translation
Process by which information encoded in mRNA is used to assemble a protein at a ribosome
Occurs on a Ribosome
mRNA tRNA

39. RNA What is the Main Job of RNA?
It retrieves the protein code from DNA and carry out the processes needed to produce proteins.
What are the basic units or monomers of DNA?
Nucleotides
Where is RNA found?
It is found both inside and outside of the nucleus.

40. DNA What is the Main Job of DNA?
It contains the code for the proteins an organism may produce.
What are the basic units or monomers of DNA?
Nucleotides make up DNA.
Where is DNA found?
It is found mostly in the nucleus of a cell making up its chromosomes.