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1/26/17 Aim: I can predict how a mutation effects the production of a protein molecule.
LAUNCH: HOMEWORK: Complete the back of the launch . Article assignment DUE TUES 1/31/17
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LAUNCH
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THINK ABOUT IT What if you dialed the wrong area code for someone you wanted to call? Example: Instead of
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HW
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Class activity: How DNA controls the workings of the cell
When you are done with your test, you will begin to work on the lab below. How DNA controls the workings of the cell
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EVALUATION WHAT DID YOU LEARN TODAY?
IF THERE IS AN ERROR DURING REPLICATION, WHAT IS THE EFFECT? WRITE ONE QUESTION THAT YOU STILL HAVE ABOUT WHAT YOU LEARNED TODAY TO DISCUSS TOMORROW.
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Genes are found on chromosomes
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Mutations What are they? How do they affect protein synthesis?
Sometimes DNA may be altered by something in the environment and that alteration MAY lead to a change in gene expression. This type of a change in the DNA is known as a mutation.
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(specific shape & function) Determines the trait expressed
MUTATIONS DNA base sequence is the sequence or order of the nitrogen bases in DNA. The order that the nitrogen bases exist in DNA is important because it is the instructions on the order in which to assemble amino acids to make proteins. Gene (has base sequence) ↓ Specific protein (specific shape & function) Determines the trait expressed (Blue eyes)
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THINK ABOUT IT It is important that DNA be replicated exactly because…
What would happen if a mistake occurred during DNA replication?
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What is a mutation? ATTCGTTATCGGTTA ATTCCTTATCGGTTA
Any change in the sequence of nucleotides in a DNA molecule is a gene mutation. Mutations in DNA occur when bases are deleted, changed, added, or moved. This causes a change in the shape of the protein, which will then affect its function. ATTCGTTATCGGTTA Gene for a protein ATTCCTTATCGGTTA Mutated gene
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Think about it Replace the letter “t” with the letter “f” in the following sentence “I baked a tart. Change: “I baked a _art. Does the meaning change? How? f
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Gene Mutations There are 2 ways in which DNA mutations can occur:
1. If a mutation occurs in a sex cell, it may be passed on to, or inherited by the offspring. 2. Mutations can be acquired. This is caused by mutagens (mutagenic agents)– substances which cause mutations. Examples include: x-rays, toxic chemicals, UV radiation, and nicotine.
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Types of Mutations Point mutation: change in one base of the gene sequence Original : The fat cat ate the wee rat. (If the c was changed to an h then…) Point mutation: The fat hat ate the wee rat.
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Types of Mutations Frame-shift mutation: one or more bases are inserted or deleted. Original: The fat cat ate the wee rat. (If the t in cat is deleted then…) Frame-shift mutation: The fat caa tet hew eer at.
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Types of Mutations Deletion: mutations that result in missing DNA.
Original : The fat cat ate the wee rat. (if cat were deleted then…) Deletion: The fat ate the wee rat.
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Types of Mutations Insertion: mutation that results in additional DNA being added. Original : The fat cat ate the wee rat. (If xlw were inserted then…) Insertion: The fat cat xlw ate the wee rat.
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1/27/17 Aim: I can predict how a mutation effects the production of a protein molecule.
LAUNCH: HOMEWORK: Article assignment DUE TUES 1/31/17
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HW
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Mutations worksheet How do mutations in DNA affect the production of proteins?
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Mutations Worksheet ORIGINAL STRAND DNA GTA GTT TCA CGG ACA CAT TCT
mRNA CAU CAA AGU GCC UGU GUA AGA PROTEIN HIS-GLN-SER-ALA-CYS-VAL-ARG MUTATED STRAND 1 DNA GTG GTT TCA CGG ACA CAT TCT mRNA CAC CAA AGU GCC UGU GUA AGA MUTATED STRAND 2 DNA GTT GTT TCA CGG ACA CAT TCT mRNA CAA CAA AGU GCC UGU GUA AGA PROTEIN GLN-GLN-SER-ALA-CYS-VAL-ARG
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1/31/17 Aim: I can determine the effect of mutations on gene expression.
LAUNCH: complete questions 1-2 on back of notes (Under “HOMEWORK.” HOMEWORK: Article assignment DUE TODAY REVIEW BOOK Read page , then answer questions 1-13
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LAUNCH Amino acids are the building blocks required to synthesize proteins. The proteins are assembled at the ribosomes. DNA has the code for assembling amino acids in a specific sequence which produces a specific protein. A mutation is a change in the DNA sequence of a gene or a change in structure of a chromosome.
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Brain pop: mutations Mutations
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Effects of mutations Mutations in body cells can cause cancer: Mutated genes cannot make the proteins that would normally prevent a cell from reproducing. Mutations in gametes are passed on to the offspring: Mutations can only be passed on if they are present in the sex cells. Some mutations lead to genetic diseases: Sickle-cell anemia, cystic fibrosis, Tay-Sachs disease, Huntington’s disease are all the results of adding, deleting, or changing the bases in DNA
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Genetic Disorders (single gene mutation):
Sickle-cell anemia is caused by a gene mutation. The wrong amino acid is synthesized which results in abnormal form of hemoglobin (HbS) produced. HbS molecules tend to clump together, making red blood cells sticky, stiff, and more fragile, and causing them to form into a curved, sickle shape red blood cells being sickle-shaped instead of oval.
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Genetic Disorders: Tay Sachs Disease is caused by a genetic mutation in the HEXA gene. This mutation interferes with the enzymes job to help break down toxic material. The build up plays a critical role in damaging the brain and spinal cord. Those affected live into early childhood
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Detection of Genetic Disorders:
Some genetic mutations may be detected either before or after birth using these techniques: Blood and urine test – can be used to detect carriers of sickle-cell anemia Karyotyping – enlarged photo of chromosomes in a cell. Amniocentesis - the removal of amniotic fluid of a pregnant woman. The fluid contain fetal cells which can be analyzed.
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Down’s Syndrome – Chromosomal mutation
Karyotyping – used to detect genetic mutations such as Down’s Syndrome, where the baby has 47 chromosomes instead of 46. female
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Two different color eyes - mutation
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Effects of Mutations Mutations are not always bad.
Genetic mutations result in genetic variation among a population, which results in evolution. Example: A long time ago, giraffes didn’t have long necks. A genetic mutation resulted in a giraffe with a longer neck. The longer neck giraffe could obtain food easier, therefore survived and reproduced, giving its offspring the gene for long necks.
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Effects of mutations Some mutations lead to genetic advantages: All evolution results from minor genetic mutations in its population. These advantageous genes are then passed onto the offspring. (Mutations are sometimes random (during mitosis or meiosis) and cause variation.) Mutations provide a way for scientists to track species ancestry: Species with similar nucleotide sequences in a particular gene are more closely related than species with sequences that are less similar.
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Evolution of sickle cell anemia
Youtube
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Genotype vs. Phenotype Genotype: the genetic code an organism contains in its DNA. Not all traits in an individual’s DNA will be expressed in the organism. Ex.- You can carry a gene for blue eyes and not actually have blue eyes. Phenotype: traits expressed in an organism, either observable or not observable. Ex.- eye color or the presence of specific enzymes
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What is phenotype dependent on?
Phenotype is dependent on two factors: The organism’s genotype (DNA code) The environment the organism lives in. Example: The effect of temperature on hair color in the Himalayan rabbit.
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The Himalayan Rabbit The fur color on extremities (feet, ears) change color depending on temperature. Normal Temperatures Cold Temperatures
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Environmental factors effect genes getting turned on and off…
Think about it: What happens to your pupils when it is dark?? What about when it is bright?? Pupils dilating
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Gene Expression and the Order of the Operon
Amoeba sisters
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Environment Influence on gene expression:
Although you are born with all of your inherited traits, environmental conditions may alter the expression of your genes. Environmental conditions include: the sun, the temperature, foods you eat or drugs you take (steroids). Although you are born with all of your inherited traits, environmental conditions may alter the expression of your genes. Environmental conditions include: the sun, the temperature, foods you eat or drugs you take (steroids).
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MUTATIONS
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Tanning Excessive sunlight may alter skin color and texture. In extreme cases, it may alter DNA resulting in skin cancer.
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Skin texture changed by excessive sun exposure
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Nutrition and Exercise
Eating a balanced diet and exercising may build muscle that would not normally be present.
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Using Steroids can alter structural proteins:
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Gregg Valentino- Before and After
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Mutations may cause Tumors and Cancers
Tumor is caused by abnormal cell growth Benign: Tumor, not cancerous Encapsulated Malignant: Cancerous tumor Invasive Metastasis- Spread of malignant cells. Cancer — Disease that results from a malignant tumor
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Mutations which cause malignant tumors and cancers can be caused by
Carcinogens: Cancer causing substances Some examples of carcinogens are: Chemicals X-rays Radiation
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Brain pop: mutations Cancer
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Amoeba sisters: Mutations, the potential power of a small change.
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Inherited Breast and Ovarian Cancers
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Mutations: Pure Nature Specials: Mutation, the science of survival
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Law and order: SVU Clocks: Season 8 , Episode 2
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