5/1 Agenda Sickle Cell Anemia Review Group Review Activities Turn in: FRQ question Homework: 1. Enzyme Video and Notes 2. Protein Synthesis Video and Notes 3. Write your own MC questions about protein synthesis and enzymes (3 questions for each topic- total 6 questions)

6 Degrees of Separation Sickle Cell  Evolution Sickle Cell  Natural Selection Sickle Cell Protein Structure Sickle Cell  DNA Mutations Sickle Cell  Genetics Sickle Cell  Heterozygote Advantage

Sickle Cell Sickle Cell is an example of a point mutation (1 base pair difference in DNA sequence) Changes a glutamine for a valine in the amino acid chain Valine has different interactions with amino acid chain resulting in a ‘clumped’ secondary structure The ‘clumped’ protein structure results in sickle shaped blood cells These sickle shaped blood cells prevent malaria infection Sickle Cell traits are more common in areas where malaria is endemic Individuals with the sickle cell trait are less likely to die from malaria—selective advantage, but they have sickle cell—selective disadvantage Individuals that are heterozygous have some abnormal shaped blood cells but few malaria symptoms – selective advantage Heterozygote Advantage Sickle cell is a recessive trait, so two copies must be inherited for the disease to show

Sickle Cell and DNA Mutations DNA  RNA  Protein

Sickle Cell and Protein Structure Primary- amino acid sequence held together by peptide bonds Secondary- alpha helix and beta pleated sheets held together by hydrogen bonds Tertiary- hydrophobic interactions, Van er Waals forces, ionic bonds, covalent bonds, disulfide bridges between helices or sheets Quaternary- hydrophobic interactions, Van der Waals forces, ionic bonds, covalent bonds, disulfide bridges between polypeptide chains

Sickle Cell and Protein Structure

Sickle Cell and Natural Selection Individuals with sickle cell are immune to malaria Sickle Cell represents a selective advantage to individuals living in an area where malaria is endemic In those areas, individuals with the sickle cell trait survived longer and reproduced more, passing the sickle cell trait on Over time, the sickle cell trait became more common Change in allele frequency = evolution In areas with no malaria, NOT have sickle cell is advantageous  less common

Sickle Cell and Natural Selection

Sickle Cell and Heterozygote Advantage The heterozygous genotype has a selective advantage over homozygous dominant or recessive Allows a ‘diseased’ allele to persist in a population

Sickle Cell and Genetics Example of codominance Both traits show up in the heterozygous genotype Heterozygous is advantageous More common in populations where malaria is endemic

Sickle Cell and Genetics

Sickle Cell Anemia Group Review In your group, each person will pick TWO topics Natural Selection Protein Structure DNA Mutations Protein Synthesis Genetics Each person is responsible for creating 1 review resource for that topic Include things like… Explanations of all key words Diagrams/Pictures/Graphs Connection to any labs or math problems Practice FRQ or MC problems Anything else helpful Posters, concept maps, flashcards, quizlets are all acceptable The last 15 minutes of class will be spent with you presenting to your group I expect a more in depth level of detail that what we went over in these slides Each topic will be a separate classwork grade