1. BLA Biology ( )
June 6th 2017

2. Ch. 11 & 12 Test, Wednesday Jun 7th 2017
COPY DATE, TOPIC & OBJECTIVE ON PG Date:
Ch. 12. Gene Action
Ch. 11 & 12 Test, Wednesday Jun 7th 2017
Topic(s) – Gene Expression: RNA, Transcription, Translation & Protein Synthesis (Day 2)
Objective: SWBAT 1) Learn translation and protein synthesis using animation, notes and power point lecture; 2) Compare transcription and translation; and 3) Learn about mutation
COPY HW, COPY& ANS.DO-NOW; COPY & ANS. EXIT TICKET ON PG. 67
HW: Organize your science journal, Unfinished CW/HW (if any), ET
Complete Transcription & Translation Wksht.
Work on Study Guide & Study for test
Do Now (Refer to slip): None!
Refer to the power point pkts
CW: Gene Expression – Translation (
Transcription vs. translation (
Exit Ticket**: Refer to slip!
Body of Lesson: (DO NOT HAVE TO COPY)
1) DN & DN Debrief ) Gene Expression 3) ET

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

4. The Genetic Code
A codon consists of 3 nucleotides and it 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

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

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

8. Codons and Anticodons Codon: Sequence of 3 bases
Anticodon: Sequence of 3 bases complementary to a codon
Example: Codon ACU
Anticodon UGA
UGA
ACU

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

10. 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

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

12. Transcription vs. Translation

13. 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

14. Template Strand
Complementary RNA strand for the following DNA sequence
DNA 3’-GCGTATG-5’
RNA 5’-CGCAUAC-3’

15. 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

16. 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

17. RNA Polymerase

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

19. 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

20. 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

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

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

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

24. 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

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

26. 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

27. 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

28. 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

29. 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

30. 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

31. 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

32. 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

33. 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

34. Messenger RNA (mRNA) Primary structure of a protein A U G C mRNA 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

35. Summarizing Protein Synthesis

40. DNA Replication vs. Protein Synthesis

41. Hallmarks of Genetic Code

44. Mutations
Mutations are essential to evolution; they are the raw materials of genetic variation. Without mutation, evolution could not occur.

45. (Agents that cause mutation)
Mutagens
(Agents that cause mutation)
Physical Factors
1. High Temperature
2. Radiation (X-rays, UV radiation, Ionization radiation-Alpha, Beta & Gamma Rays, Cosmic Radiation
Chemical Factors
1. pH Changes
2. Chemicals
a. Aflatoxins (produced by mold)
b. Pesticides
c. Colchicine
d. Ozone

46. Mutations Chromosomal Mutation Gene Mutation
Involves change in the structure or number of chromosomes
Gene Mutation
Involves change in one or more of the nucleotides in a strand of DNA (Gene)

52. Point Mutation
Sickle Cell disease is the result of one nucleotide substitution
Occurs in the hemoglobin gene
Autosomal recessive trait (Chromosome 11)

53. Point mutations in our lives!
-Sickle cell anemia is a blood disease caused by a point mutation.
-A single nucleotide is changed from “A” to “T” which causes the amino acid to change from glutamic acid to valine:
Normal: ACT CCT GAG GAG
Amino Acids: Thr – Pro – Glu – Glu
Sickle cell: ACT CCT GTG GAG
Amino acids:Thr – Pro – Val – Glu

54. Point mutations in our lives!
-People with sickle cell anemia often experience a lot of pain and swelling and have trouble exercising.
Sickle cells do not move smoothly
through blood vessels like normal cells do.
Sickle cells get stuck and cause blood clots.
Sickle cells also can’t carry
Oxygen as effectively as normal
Cells.

55. A case study of the effects of mutation: Sickle Cell Anemia

56. A case study of the effects of mutation: Sickle Cell Anemia (Contd…)
3. Effects at cellular level 4. Negative effects at the whole organism level
5. Positive effect at the whole organism level: Resistant to malaria

57. Mutation – A chain of causation
What happens at the DNA level propagates up to the level of the organism.
Single mutation can have a large effect (both negative & positive in case of sickle cell disease).
Changes at the DNA level propagate up to the phenotype.

58. Stages of Mitosis (Onion Root Tip)

59. Differences between Mitosis & Meiosis
1. Results in two identical diploid somatic cells
1. Results in four different haploid gametic cells
2. No laws apply
2. Both law of segregation & law of independent assortment apply
3. No crossing over takes place
3. Crossing over takes place
4. PMAT happens only once
4.PMAT happens twice: PMAT – I and PMAT – II
5. No pairing of homologous chromosomes
5. Homologous chromosomes pair
6. Involved in growth & repair of damaged tissues
6. Involved in reproduction
7. Asexual
7. Sexual