1. BIOLOGY B-4 MOLECULAR GENETICS BIOTECHNOLOGY PART 2
Chapters 12 & 13
B-4: Demonstrate an understanding of the molecular basis of heredity
(indicators4.1-4,9)

2. Notes (B-4.4) Protein Synthesis Text sec 12-3
How are traits expressed (proteins made) in a cell?
What role do the 3 types of RNA play in making a protein?
How does transcription and translation make a protein?
Summarize transcription and translation.

3. How are traits expressed (proteins made) in a cell?
DNA is the “master plan” (original copy) and can NOT leave the nucleus
RNA carries copies to the ribosome to assemble proteins
DNA = blue print : RNA = construction workers
Review: A gene is a segment of DNA with instructions to make a specific protein (trait)

4. What role does RNA play in making a protein?
mRNA (messenger)
Complimentary copy of DNA
Ex: DNA = TAG
mRNA = AUC
Codon (code for 1 amino acid) = 3 bases
Ex: AUC  Isoleucine
tRNA (transfer)
Carries specific amino acid based on mRNA
Anti-codon (transports 1 amino acid) = 3 bases
rRNA (ribosomal)
Makes up structure of ribosome

5. How does transcription and translation make a protein?
Makes copy of instructions (transcribes)
mRNA is the copy of DNA goes to ribosome (reminder- DNA cannot leave nucleus)
Translation
Reads instructions to build protein
Ribosomes assemble amino acids into a protein (use instructions from mRNA)

6. Summarize protein synthesis.
(1st) Transcription
In the Nucleus
DNA is copied to Mrna
mRNA leaves nucleus, goes to ribosome
(2nd) Translation
In the cytoplasm, Ribosome reads mRNA
Codon (mRNA) calls for specific Anticodon (tRNA)
Anticodon carries amino acid
Amino acids are linked together to make a chain (polypetide or protein)
“stop” codon releases PROTEIN

7. Protein Synthesis Step 1 - Transcription Step 2 - Translation Nucleus
mRNA
Lysine
Phenylalanine
tRNA
Methionine
Step 2 - Translation
Anti-codon
Ribosome
mRNA
codon

8. Translation Continued
Growing polypeptide chain
Ribosome
tRNA
Lysine
tRNA
mRNA
Translation direction
Ribosome

9. Practice Protein Synthesis
#1 DNA  AGC GTG CCA
(Transcribe) mRNA __________________
(Translate) tRNA ____________________
Amino Acid: __Serine; Histidine; Glycine_
#2 DNA  GTG ACA ATC
Amino Acid: ___Histadine; Cysteine; Stop

10. ANSWER: Practice Protein Synthesis
#1 DNA  AGC GTG CCA
(Transcribe) mRNA ___UCG CAC GGU_
(Translate) tRNA ____ AGC GUG CCA _
Amino Acid: __Serine; Histidine; Glycine_
#2 DNA  GTG ACA ATC
(Transcribe) mRNA __CAC UGU UAG _
(Translate) tRNA ____GUG ACA AUC__
Amino Acid: ___Histadine; Cysteine; Stop

11. Each codon CODES for 1 amino acid:
Start codon

12. 2nd Base 1st Base U C A G 3rd Phe Leu Ser Tyr STOP Cys Trp Pro His Gln
Arg
Ile
*Met*
Thr
Asn
Lys
Val
Ala
Asp
Glu
Gly

13. Codon Chart / Wheel Practice:
Ex: DNA AAC GGA
mRNA: _UUG CCU____
Amino Acid: _Leucine; Proline__
(3)DNA: TAT ATT
mRNA: ________________
Amino Acid: ____________
(4)Amino Acid: Methonine HistIdine
mRNA: _____________________
DNA: _____________________

14. ANSWER: Codon Chart / Wheel Practice:
(3)DNA: TAT ATT
mRNA: _AUA UAA_____
Amino Acid: __Isoleucine; Stop__
(4)Amino Acid: Methonine Histidine
mRNA: __AUG _CAC or CAU__
DNA: ___ TAC__GTG or GTA__

15. B-4.8 Mutations (sec 12-4) What is a gene mutation?
What can cause a mutation?
Summarize the consequences of mutations in body cells.
Summarize the consequences of mutations in gametes (egg/sperm).
Can mutations be beneficial?
Explain how genetic diseases relate to mutations.

16. Different Genes = Different Traits
A gene is a segment of DNA that codes for 1 protein which expresses a trait. What would happen if the DNA sequence in a gene is changed?

17. What is a gene mutation?
Gene mutations involve a change in a single gene (changes a single protein); .
Substitution: replaces one nucleotide
affects one amino acid
EX: Sickle Cell Anemia
Insertion or Deletion: nucleotide is added or deleted
affects EVERY amino acid beyond the mutation
Sometimes the protein will be able to function, but imperfectly…
Sometimes the protein won’t
function at all…
Sometimes it will cause severe
problems for the organism.

18. What can cause a mutation?
Errors in DNA replication
DNA doubled for cell division
Small differences in copy = mutant cell
Mutagen is anything that causes changes in DNA (causes mutations) – cause DNA to break down
Examples: UV rays, Radiation, Chemicals

19. Consequences of mutations
Mutations in BODY CELLS:
ONLY effect that organism
EX: Aging (replication errors), Skin Cancer (uv rays), etc…
Mutations in GAMETES (egg/sperm):
May be passed on to offspring
EX: Genetic Disorders
SOME mutations are BENEFICIAL: Adaptations are mutations that increase survival

20. Genetic Diseases
About 4,000 diseases stem from our genes, which began as a mutation.
These genes passed from one generation to the next (parents to children)
Examples:
Heart Disease, Many Cancers (breast, prostate)
Combination between genes and environment
Dwarfism, Huntington’s disease
PKU, Albinism, Cystic Fibrosis
Sickle cell

22. Notes (B-4.9) Biotechnology Sec 13-1,2,3,4
Explain the difference between inbreeding and hybridization.
What is a gene map?
What is a genome?
What is a GMO? Summarize types of GMO in plants and bacteria?
What is a clone? Summarize the cloning process?

23. Explain inbreeding and hybridization?
Selective breeding is artificially selecting and breeding only organisms with a desired trait to produce the next generation.
INBREEDING : Breeding organisms with same traits
Maintain same traits
DRAWBACK:
Recessive gene defects show up more frequently after several generations
Examples:
Dog Breeds are maintained through inbreeding
Domestic animals & crops
HYBRIDIZATION: Breeding organisms with different traits
Produce combination of traits
BENEFIT: Often offspring are stronger (hardier) because of the increased genetic variation.
Examples:
“Labradoodles”
Crossing disease-resistant plants with high food-producing plants ---- increase overall food production

24. Hybridization - examples

25. videos Ligers – Hybridization
Ligers – Male lion w/ Female tiger
Tigon – Female lion w/ Male tiger
Super Cow – Inbreeding

26. How are gene maps and genomes vital to genetic engineering?
Genetic engineering is the process of replacing specific genes in an organism to express a desired trait. Scientists Use:
Gene maps: show specific location of genes on chromosomes
Genome: all the genetic material of a species mapped out (all possible variations). The HUMAN Genome Project mapped all the DNA of human genes.
This allows us to isolate, remove, and insert individual genes.

27. Genetic Engineering: GMO – transgenic organisms
GMO = Organism with genes from other species inserted into its genome.
CROPS: contains genes to resist frost, disease, and insects.
BACTERIA: contains human gene for insulin or human growth hormone (create medicine)
ANIMALS: used for gene therapy trials
Onco-mice (insert gene for cancer) – test caner drugs
Obese mice (knockout gene that regulates hunger)
Glowing monkey (gene from jelly fish) – first successful primate.

28. Top 5 franken animals

29. Genetic Engineering: Gene Therapy
GENE THERAPY = scientists insert a normal gene to replace mutated gene which can cure disease.
Limited success and use due to:
Immune system rejections
Short-lived effects (not permanent cure)
Many disorders are caused by multiple genes
Recent clinical trials:
X-linked SCID, ADA-SCID, Parkinson’s Disease
Other gene therapy studies:
Cancer, HIV,

30. Genetic Engineering: Stem Cells
Stem cells are undifferentiated cells that have the potential to become specialized.
Therapy using stem cells can replace tissue that is deficient due to disease or damage.
Adult stem cells: Bone Marrow transplants, Umbilical cord transplants (currently used)
Embryonic stem cells: research stage – hopes to find treatments for Parkinson’s and other diseases.

31. Stem cells

32. Genetic Engineering: Cloning
CLONE = Identical copy of a gene or an entire organism.
Natural Cloning: Identical twins, Asexual reproduction, Plants (vegetative propagation – cuttings)
Genetically Engineered Cloning:
DNA/gene cloning = Isolate DNA (gene) and insert into bacteria plasmid(dna) to make copies
Therapeutic Cloning = Embryo Cloning to make stem cells for research
Create organs for transplants
Reproductive Cloning = creating an entire organism; Dolly the sheep was the 1st cloned mammal 1997
Save endangered animals / Negatives: cloning entire organisms can result in genetic disorders or health problems.

33. Plant Cloning

35. Cloned Cat “CC”
Left is “Rainbow” and right is her clone “CC”

36. Cloning Process Body Cell is taken from a donor animal
Egg cell is taken from a donor animal and nucleus is removed
The egg (w/out a nucleus) is fused with the body cell…. Forms embryo
Embryo is implanted into uterus of a “foster” mother.

37. Figure 13-13 Cloning of the First Mammal
Section 13-4
A donor cell is taken from a sheep’s udder.
Original animal being cloned
Donor Nucleus
These two cells are fused using an electric shock.
Fused Cell
Egg Cell
The nucleus of the egg cell is removed.
An egg cell is taken from an adult female sheep.
The fused cell begins dividing normally.
Cloned Lamb
Embryo
The embryo develops normally into a lamb—Dolly
The embryo is placed in the uterus of a foster mother.
Foster Mother