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Nucleic Acids

Nucleic Acids. Nucleic Acids. Nucleotides = monomers of DNA/RNA (hereditary info) Polynucleotides = polymers of nucleotides Nitrogenous base Pyrimidines = Single Carbon ring  Cytosine, Thymine and Uracil (C,T,U) Purines = Double Carbon ring  Adenine and Guanine (A,G)

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Nucleic Acids

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  1. Nucleic Acids

  2. Nucleic Acids • Nucleotides = monomers of DNA/RNA (hereditary info) • Polynucleotides = polymers of nucleotides • Nitrogenous base • Pyrimidines = Single Carbon ring  Cytosine, Thymine and Uracil (C,T,U) • Purines = Double Carbon ring  Adenine and Guanine (A,G) • Pentose (5-Carbon) sugar • Ribose (RNA) • Deoxyribose (DNA) (lacks one Oxygen) • Phosphate group biologyjunction.com

  3. Nucleic Acids • DNA = Double polynucleotide chain – helix structure. • Blueprints for all the actions of a cell; stays in nucleus. • Chromosome = Single long DNA molecule (one double helix) each containing hundreds of genes. • Humans = 23 chromosome pairs. • Genome = Sum of all the genes in an organism. • Humans = 24,000 genes

  4. Nucleic Acids • Structure of DNA • 2 sugar-phosphate backbones are anti-parallel (divided highway) • Held together by Hydrogen bonds between the paired bases. familyhistory101.com

  5. Complimentary strands = copying a strand of DNA means you are transmitting identical information on to daughter cells.

  6. The Central Dogma • DNA is the master copy • RNA is the message carrier • Proteins are the product DNA  RNA  Protein

  7. Proteins

  8. Proteins • Protein function… • Structural support • Storage (nutrients) • Transport • Cellular communications (EX: leptin) • Movement (motor proteins) • Defense against foreign substances (antibodies) • Catalyze chemical reactions (enzymes!)

  9. Proteins • Enzymes are a type of protein that are a biological catalyst • Catalysts = Speed up chemical reactions by lowering the activation energy (energy needed to start reaction) • Unchanged in process • Get recycled thousands upon thousands of times… in a single second • Ability to catalyze reactions depends on the enzyme’s shape

  10. Proteins • Protein structure… • Most structurally sophisticated molecules known • Thousands of different shapes • Composed of 1 or more polypeptides • Each type of protein has a unique conformation, or 3-D shape

  11. Proteins • Amino acids = organic monomers of polypeptides • Alpha Carbon • Amino group • Carboxyl group • Hydrogen atom • Side chain (R group) aloeveraibs.com

  12. Proteins • Polypeptides form when amino acids link together • Carboxyl group of one AA bonds to the amino end of another • Dehydration reaction  peptide bond R R R R

  13. Proteins • Side chains (R groups) • 20 different side chains, so 20 different amino acids. • Basis of thousands of types of proteins • The physical and chemical properties of the side chain determine the unique character of the amino acid. • Polar uncharged, polar acidic or polar basic • Nonpolar

  14. Examples of amino acids Nonpolar Polar Acidic  Polar  Polar Basic 

  15. Essential Amino Acids • Essential amino acidsAmino acids the body is unable to synthesize on its own. • Phenylalanine • Valine • Threonine • Tryptophan • Isoleucine • Methionine • Leucine • Lysine • Histidine • Note: Cysteine, tyrosine & arginine are required by infants and growing children. survivaltopics.com

  16. Proteins • 4 levels of protein structure • Primary structure = Unique sequence of amino acids • Based on covalent bonds between amino acids • NOT RANDOM  specified in DNA sequence of nucleotides

  17. Proteins • 4 levels of protein structure • Secondary structure = Coils and folds that occur mostly due to hydrogen bonding between the amino and carboxyl groups • Not due to bonds between side chains wikipedia.org  sheet  helix

  18. Beta sheets dominate in fibrous proteins, such as a spider’s web silk Reinforcement of the H bonds makes silk stronger than steel of the same weight dearbornschools.org

  19. Proteins • 4 levels of protein structure • Tertiary structure = 3-dimensional structure of a polypeptide • Stabilized by lots of weak bondsand the hydrophobic/hydrophilicinteractions of the side chains.

  20. Proteins • 4 levels of protein structure • Quaternary structure = Multiple polypeptide subunits (2+) • Hemoglobin has four subunits

  21. Proteins • Side chains interact with each other to form an active site, which is where other molecules can bind to the protein. Ligand = any ion or molecule that bonds to the active site. Lock-and-key model = refers to the specificity of the bonding. student.biology.arizona.edu

  22. Proteins • Shape is EVERYTHING when it comes to protein • Mutations can cause important changes in protein structure and therefore their function. • Glutamic acid  Valine in hemoglobincauses the disease sickle cell anemia

  23. Sickle Cell Disease

  24. Proteins • The environment can affect protein shape • Denatured = Tertiary structure is destroyed • Heat • Organic solvents (ethanol) • Acids (acetic acid) • pH changes • Etc. wikipedia.org

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