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)

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.

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)

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

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)

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

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

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

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

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

Each codon CODES for 1 amino acid: Start codon

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

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: _____________________

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__

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.

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? http://www.cancer.gov/cancertopics/understandingcancer/genetesting/page7

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 http://ghr.nlm.nih.gov/handbook/illustrations/mutationtypes?show=missense 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.

What can cause a mutation? Errors in DNA replication DNA doubled for cell division Small differences in copy = mutant cell http://evolution.berkeley.edu/evolibrary/article/0_0_0/mutations_04 Mutagen is anything that causes changes in DNA (causes mutations) – cause DNA to break down Examples: UV rays, Radiation, Chemicals

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

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 http://evolution.berkeley.edu/evolibrary/article/0_0_0/mutations_06

http://www.cancer.gov/cancertopics/understandingcancer/genetesting/page17

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?

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 http://www.youtube.com/watch?v=Nmkj5gq1cQU 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

Hybridization - examples

videos Ligers – Hybridization http://www.youtube.com/watch?v=txcbe4EtuUw Ligers – Male lion w/ Female tiger Tigon – Female lion w/ Male tiger Super Cow – Inbreeding http://www.youtube.com/watch?v=Nmkj5gq1cQU

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.

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. http://www.youtube.com/watch?v=xuWvg7Il9VY

Top 5 franken animals http://www.youtube.com/watch?v=004Iycd9a30

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,

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.

Stem cells

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.

Plant Cloning http://www.biotechnologyonline.gov.au/biotec/cloneplant.html

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

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.

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