1. PROTEIN SYNTHESIS

2. DNA and Genes

3. DNA DNA contains genes, sequences of nucleotide bases
These Genes code for polypeptides (proteins)
Proteins are used to build cells and do much of the work inside cells

4. Genes & Proteins
Proteins are made of amino acids linked together by peptide bonds
20 different amino acids exist

5. Amino Acid Structure

6. Polypeptides
Amino acid chains are called polypeptides

7. DNA Begins the Process DNA is found inside the nucleus
Proteins, however, are made in the cytoplasm of cells by organelles called ribosomes
Ribosomes may be free in the cytosol or attached to the surface of rough ER

8. Starting with DNA DNA ‘s code must be copied and taken to the cytosol
In the cytoplasm, this code must be read so amino acids can be assembled to make polypeptides (proteins)
This process is called PROTEIN SYNTHESIS

9. What macromolecule builds cells?
Lipids
Proteins
Carbohydrates
Nucleic Acids 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

10. What are proteins made of?
DNA
RNA
Amino Acids
Nucleic Acids 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

11. How many amino acids exist?10 20 30 46 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

12. A chain of amino acids is a:
Protein
Polypeptide
Both A & B
None of the Above 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

13. Where are proteins made?
Cytosol
Mitochondria ER
Ribosomes
Nucleus 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

14. RNA

15. RNA is the BLUEPRINT of the Master Plan
Roles of RNA and DNA
DNA is the MASTER PLAN
RNA is the BLUEPRINT of the Master Plan

16. RNA Differs from DNA RNA has a sugar ribose
DNA has a sugar deoxyribose

17. Other Differences RNA contains the base uracil (U) DNA has thymine (T)
RNA molecule is single-stranded
DNA is double-stranded
DNA

18. Structure of RNA
Like DNA, RNA is a polymer of nucleotides. In an RNA nucleotide, the sugar ribose is attached to a phosphate molecule and to a base, either G, U, A, or C. Notice that in RNA, the base uracil replaces thymine as one of the pyrimidine bases. RNA is single-stranded, whereas DNA is double-stranded.

19. .
Three Types of RNA
Messenger RNA (mRNA) copies DNA’s code & carries the genetic information to the ribosomes
Ribosomal RNA (rRNA), along with protein, makes up the ribosomes
Transfer RNA (tRNA) transfers amino acids to the ribosomes where proteins are synthesized

20. Messenger RNA Long Straight chain of Nucleotides Made in the Nucleus
Copies DNA & leaves through nuclear pores
Contains the Nitrogen Bases A, G, C, U ( no T )

21. Messenger RNA (mRNA) Carries the information for a specific protein
Made up of 500 to 1000 nucleotides long
Sequence of 3 bases called codon
AUG – methionine or start codon
UAA, UAG, or UGA – stop codons

22. Ribosomal RNA (rRNA)
rRNA is a single strand 100 to 3000 nucleotides long
Globular in shape
Made inside the nucleus of a cell
Associates with proteins to form ribosomes
Site of protein Synthesis

23. The Genetic Code A codon designates an amino acid
An amino acid may have more than one codon
There are 20 amino acids, but 64 possible codons
Some codons tell the ribosome to stop translating

24. The Genetic Code
Use the code by reading from the center to the outside
Example: AUG codes for Methionine

25. Name the Amino Acids
GGG?
UCA?
CAU?
GCA?
AAA?

26. Remember the Complementary Bases
On DNA:
A-T
C-G
On RNA:
A-U

27. Transfer RNA (tRNA) Clover-leaf shape
Single stranded molecule with attachment site at one end for an amino acid
Opposite end has three nucleotide bases called the anticodon

28. Transfer RNA
amino acid
attachment site U A C
anticodon

29. Codons and Anticodons
The 3 bases of an anticodon are complementary to the 3 bases of a codon
Example: Codon ACU
Anticodon UGA
UGA
ACU

30. What sugar is found in RNA?
Glucose
Sucrose
Ribose
Deoxyribose 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

31. What are the 4 nitrogenous bases in RNA?
A G C T
A G C U
A G T U
G C T U 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

32. DNA has __ strand(s), RNA has ____ strand(s).
2 , 2
2 , 3
1 , 2
2 , 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

33. The type of RNA that transfers amino acids to ribosomes.
snRNA
mRNA
rRNA
tRNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

34. The tyoe of RNA that makes up the ribosome.
snRNA
mRNA
rRNA
tRNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

35. The type of RNA that copies DNA’s code.
snRNA
mRNA
rRNA
tRNA
Small nuclear ribonucleic acid (snRNA) is a class of small RNA molecules that are found within the nucleus of eukaryotic cells. They are transcribed by RNA polymerase II or RNA polymerase III and are involved in a variety of important processes such as RNA splicing (removal of introns from hnRNA), regulation of transcription factors (7SK RNA) or RNA polymerase II (B2 RNA), and maintaining the telomeres. They are always associated with specific proteins, and the complexes are referred to as small nuclear ribonucleoproteins (snRNP) or sometimes as snurps. These elements are rich in uridine content.
A large group of snRNAs are known as small nucleolar RNAs (snoRNAs). These are small RNA molecules that play an essential role in RNA biogenesis and guide chemical modifications of ribosomal RNAs (rRNAs) and other RNA genes (tRNA and snRNAs). They are located in the nucleolus and the Cajal bodies of eukaryotic cells (the major sites of RNA synthesis). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

36. What is a sequence of three nitrogen bases called?
DNA
RNA
Codon
Antiparrallel 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

37. What mRNA would be made from this DNA sequence: ATCGGCTAA
TAGCCGATT
ATCGGCTAA
UAGCCGAUU
TUGCCGUTT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 20

38. Transcription and Translation

39. Pathway to Making a Protein
DNA
mRNA
tRNA (ribosomes)
Protein

40. Protein Synthesis
The production or synthesis of polypeptide chains (proteins)
Two phases: Transcription & Translation
mRNA must be processed before it leaves the nucleus of eukaryotic cells

41. DNA  RNA  Protein Eukaryotic Cell DNA Pre-mRNA mRNA Ribosome Protein
Nuclear
membrane
Transcription
RNA Processing
Translation
DNA
Pre-mRNA
mRNA
Ribosome
Protein
Eukaryotic Cell

42. Transcription
The process of copying the sequence of one strand of DNA, the template strand
mRNA copies the template strand
Requires the enzyme RNA Polymerase

43. Template Strand

44. Question:
What would be the complementary RNA strand for the following DNA sequence?
DNA 5’-GCGTATG-3’

45. Answer:
DNA 5’-GCGTATG-3’
RNA 3’-CGCAUAC-5’

46. Transcription
During transcription, RNA polymerase binds to DNA and separates the DNA strands
RNA Polymerase then uses one strand of DNA as a template to assemble nucleotides into RNA

47. Transcription
Promoters are regions on DNA that show where RNA Polymerase must bind to begin the Transcription of RNA
Called the TATA box
Specific base sequences act as signals to stop
Called the termination signal

48. RNA Polymerase

49. mRNA Processing
After the DNA is transcribed into RNA, editing must be done to the nucleotide chain to make the RNA functional
Introns, non-functional segments of DNA are snipped out of the chain

50. mRNA Editing
Exons, segments of DNA that code for proteins, are then rejoined by the enzyme ligase
A guanine triphosphate cap is added to the 5” end of the newly copied mRNA
A poly A tail is added to the 3’ end of the RNA
The newly processed mRNA can then leave the nucleus

51. Result of Transcription
New Transcript
Tail
CAP

52. mRNA Transcript
mRNA leaves the nucleus through its pores and goes to the ribosomes

53. Translation
Translation is the process of decoding the mRNA into a polypeptide chain
Ribosomes read mRNA three bases or 1 codon at a time and construct the proteins

54. Transcription Translation
Transcription occurs when DNA acts as a template for mRNA synthesis. Translation occurs when the sequence of the mRNA codons determines the sequence of amino acids in a protein.
Translation

55. Ribosomes Made of a large and small subunit
Composed of rRNA (40%) and proteins (60%)
Have two sites for tRNA attachment --- P and A

56. Step 1- Initiation
mRNA transcript start codon AUG attaches to the small ribosomal subunit
Small subunit attaches to large ribosomal subunit
mRNA transcript

57. Ribosomes
Large
subunit P
Site A
Site
mRNA A U G C
Small subunit

58. Step 2 - Elongation
As ribosome moves, two tRNA with their amino acids move into site A and P of the ribosome
Peptide bonds join the amino acids

59. Initiation G aa2 A U U A C aa1 A U G C U A C U U C G A codon 2-tRNA
anticodon A U G C U A C U U C G A
hydrogen
bonds
codon
mRNA

60. Elongation G A aa3 peptide bond aa1 aa2 U A C G A U A U G C U A C U U
3-tRNA G A
aa3
peptide bond
aa1
aa2
1-tRNA
2-tRNA
anticodon U A C G A U A U G C U A C U U C G A
hydrogen
bonds
codon
mRNA

61. Ribosomes move over one codon
aa1
peptide bond
3-tRNA G A
aa3
aa2
1-tRNA U A C
(leaves)
2-tRNA G A U A U G C U A C U U C G A
mRNA
Ribosomes move over one codon

62. peptide bonds G C U aa4 aa1 aa2 aa3 G A U G A A A U G C U A C U U C G
4-tRNA G C U
aa4
aa1
aa2
aa3
2-tRNA
3-tRNA G A U G A A A U G C U A C U U C G A A C U
mRNA

63. Ribosomes move over one codon
peptide bonds
4-tRNA G C U
aa4
aa1
aa2
aa3
2-tRNA G A U
(leaves)
3-tRNA G A A A U G C U A C U U C G A A C U
mRNA
Ribosomes move over one codon

64. peptide bonds U G A aa5 aa1 aa2 aa4 aa3 G A A G C U G C U A C U U C G
5-tRNA
aa5
aa1
aa2
aa4
aa3
3-tRNA
4-tRNA G A A G C U G C U A C U U C G A A C U
mRNA

65. Ribosomes move over one codon
peptide bonds U G A
5-tRNA
aa5
aa1
aa2
aa3
aa4
3-tRNA G A A
4-tRNA G C U G C U A C U U C G A A C U
mRNA
Ribosomes move over one codon

66. Termination aa5 aa4 aa3 primary structure of a protein aa2 aa1 A C U C
terminator
or stop
codon
200-tRNA A C U C A U G U U U A G
mRNA

67. End Product –The Protein!
The end products of protein synthesis is a primary structure of a protein
A sequence of amino acid bonded together by peptide bonds
aa1
aa2
aa3
aa4
aa5
aa200
aa199

68. Messenger RNA (mRNA) Primary structure of a protein A U G C aa1 aa2
start
codon
codon 2
codon 3
codon 4
codon 5
codon 6
codon 7
codon 1
methionine
glycine
serine
isoleucine
alanine
stop
codon
protein
Primary structure of a protein
aa1
aa2
aa3
aa4
aa5
aa6
peptide bonds