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2012-06-07 01:19:32

Amino Acids
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  1. Name the structural features of an Amino Acid
    Alpha carbon, Amino group, and Carboxyl group

    • H
    • =H3N-C-COOH
    • R

    Each has a unique R group
  2. Define the structural components of a Peptide Bond.
    The peptide bond is a strong covalent bond between the alpha carboxyl group of one amino acid and the amino group of the next amino acid.
  3. What is a peptide
    when the carboxyl group of an amino acid condensates with the amino group of a different amino acid with the release of a water molecule
  4. Define buffer and explain how it applies to proteins.
    Buffers are solutions tat contain both the pronated and the deprotonated forms of a weak acid.

    Buffers are able to donate or recieve Hydrogen ions so it minimizes changes in pH when in an acid or base.

    The amino and carboxyl group of each amio acid can act as a buffer in the blood
  5. Name the 9 Non polar amino acids.
    Tryptophan, Phenylalanine, Glycine, Alanine, Valine, Isoluecine, Luecine, Methionine, Proline
  6. Name the 6 uncharged Polar Amino acids.
    Tyrosine, Serine, Threonine, Aspragine, Glutamine, Cysteine
  7. Name the 5 CHARGED polar amino acids.
    Aspartic acid, Glutamic acid - Both negative charge (acid)

    Lysine, Arginine, Histidine - Both positive charge (base)
  8. Describe Hydrophobic Interactions and which group can participate.
    Hydrophobic Interactions - Non polar hydrophobic amino acids tend to aggregate to avoid the polar molecule of water forminf hydrophobic interactions.
  9. Describe Hydrogen Bonds and which group can participate.
    Amino Acids with uncharged polar R groups can form hydrogen bonds. (N-H, O-H, or S-H can shre H with another N or O as well asn chaged amino aacids

    Hydrogen bonds are non-covalent interactions which a hydrogen atom is shared by two electronegative atom groups.
  10. Describe Ionic interaction and which grouop can participate.
    Ionic bonds are non covalent interactions formed between goups with opposite charge.

    Charged amino acids can form both hydrogen and ionic bonds.
  11. Describe disulfide bond and which group can participate.
    Cysteine - a uncharged hydrophilic amino acid is the only one that can form this bond.

    Disulfide bonds are covalent bonds that contribute to the stabilization of protein conformatino. Ot forms between the sulfu atoms of two cysteine amino acids.
  12. Describe peptide bonds and the which groups can participate.
    Peptide bonds are covalent strong bods between the alpha carboxyl of one amino acid and the amino group of the next amino acid.

    the carboxyl and amino groups lose their charged properties when used to form a peptide bond.

    Any of the 20 amino acids can be attached this way.
  13. What are proteins?
    Protiens are polypeptides are linear polymers built of 20 or more monomers called amino acids which are linked end to end.

    The difference between polypeptides and proteins is based on function. If a polypeptide has a function it is a protein.
  14. What are domains.
    Domains are structural emlements within a protein that have a specific function by themselves.

    like s spork - it is one unit but each domain (the spoon end and the fork end{both are a domain}have a specific function.
  15. What are the distinguishing features between primary, secondary, tertiary, and quatenary structures?
    Primary structures are linear sequence of amino acids that form a protein.
  16. What are the distinguishing features between primary, secondary, tertiary, and quatenary structures?
    Secondary structures are characterized by a local folding of a polypeptide backbone of amino acids into regular, repeating geometric patterns.

    the secondary structure is stablaized by hydrogen bonds between C=O and N-H groups in the peptide bond itself rather than the side chains. Therfore these structures can fom with many amino acid sequences.

    Alpha helix, Beta sheets, and loops are all secondary structures.
  17. What is an alpha helix?
    An alpha helix is a spiral with R groups extended outward from the helical axis.
  18. What is a Beta sheet?
    Beta sheet is an extended refion of polypeptide chains that lie next to one another. These regions are called STRANDS.
  19. What is a Loop?
    A loop is the part of the sezuence not in a regular folding ( alpha helix or beta sheets) which serves as a connecting region.
  20. What are the distinguishing features between primary, secondary, tertiary, and quatenary structures?

    What are Globular and Fibrous tertiary structures?
    tertiary structures are the folding and packing of the secondary structures into one structure. It is the final folded conformation of a functional group.

    Globular are spherical

    fibrous are rod like proteins.
  21. What are the distinguishing features between primary, secondary, tertiary, and quatenary structures?
    Quaternary structures are teh association of more than one polypeptide chain into multiple subunit proteins.

    Quaternary structures are only found in protiens with multiple polypeptide chains. the chains are referred to as subunits.
  22. Describe how R group interactions affect protein structure, what is the relationship between protein sequence, structure and function, and it significance in sickle cell disease.
    • r group structures affect protein structure by their classification, hydrophobic or hydrophilic.
    • This change as in sickle cell disease is caused by a mutation and replacement of hydrophilic amino acid to a hydrophobic one.

    This cause the structure to change into fibers instead of globules.

    This change in stucture results in a change in function

    Sickle cells can still carry O2 but the changed shape increases the vulnerability to lysis and minimizes membrane flexibility and deformability to migrate through narrow capillaries.