BioE 220 Chapter 4

  1. Acetylation
    The addition of one or more acetyl groups to a protein; the formation of an acetyl derivative
  2. Activation energy
    The input of energy required to initiate a chemical reaction. Enzymes increase rate of reaction
  3. Active site
    The region of an enzyme that binds substrates and catalyzes an enzymatic reaction
  4. Acylation
    The addition of one or more acyl groups to a protein
  5. Affinity
    A measure of the degree to which a substance tends to bind to another
  6. Alpha helix
    A common secondary structure of proteins in which the linear sequence of amino acids is folded into a right-handed spiral stabilized by hydrogen bonds between carboxyl and amide groups in the backbone; a coiled secondary structure of a polypeptide chain formed by hydrogen bonding between amino acids separated by four residues.
  7. Antibody
    A specialized immune protein, which helps fight infection by neutralizing pathogens and tagging them for destruction
  8. Beta sheet
    A planar secondary structure of proteins that is created by hydrogen bonding between the backbone atoms in two different polypeptide chains or segments of a single folded chain; a sheetlike secondary structure of a polypeptide chain, formed by hydrogen bonding between amino acids located in different regions of the polypeptide. 
  9. Catalyst
    A substance that increases the rate of a reaction without itself undergoing any chemical change
  10. Dimer
    A compound formed by two molecules of a simpler compound; a polymer formed from two molecules of a monomer
  11. Disulfide bond (-S-S-)
    A covalent linkage formed between two sulfhydryl groups on cysteines. Joins two proteins together or linking different parts of the same protien.
  12. Enzyme
    A biological substance produced by living organisms to increase the rate of a biochemical reaction
  13. Glycosylation
    The addition of one or more sugars to  protein or lipid molecule
  14. Hydrophobic effect
    The tendency of nonpolar groups to cluster so as to shield themselves from contact with an aqueous environment
  15. Ion channel
    A transmembrane protein that transports ions, which are otherwise impermeable to the cells
  16. Ligand
    Any molecule that binds tightly and specifically to a macromolecule, usually a protein, forming a ma romolecule-ligand complex
  17. Lineweaver-Burke plot
    A graphical model used to determine the maximum reaction rate, V_max and Michaelis constant, K_m. 
  18. Michaelis constant (K_m)
    The value equal to the substrate concentration at which the enzyme reaction proceeds at half of the max velocity
  19. Michaelis-Menten equation
    Describes the velocity of a given reaction developed from a simple model of enzyme substrate kinetics
  20. Myristoylation
    The addition of myristic acid to the N-terminal glycine residue of a polypeptide chain
  21. Nascent proteins
    Proteins that have not yet achieved their functional final folding pattern
  22. Peptide bond
    A covalent bond that links adjacent amino acid residues in proteins; formed by a condensation reaction between the amino group of one amino acid and the carboxyl group of another with the release of a water molecule
  23. Phosphorylation
    A reaction in which a phosphate group becomes covalently coupled to another molecule
  24. Post-translational modification
    The enzyme-catalyzed change to a protein made after it is synthesized
  25. Protease
    An enzyme such as trypsin that degrades proteins by hydrolyzing some of their peptide bonds
  26. Protease inhibitor
    A substance that functions by inhibiting the actions of a protease
  27. Proteolysis
    The degradation of polypeptide chains
  28. Proteome
    The complete set of proteins present in the cell
  29. Proteomics
    A branch of molecular biology concerned with determining the proteome
  30. Receptor transmembrane protein
    A transmembrane protein that has an extracellular domain that binds to molecules called ligands
  31. Sequence homology analysis
    The comparison of an unknown primary amino acid sequence to a database of known primary amino acid sequences in an attempt to identify functional capabilities of the unknown amino acid
  32. Substrate
    The molecule on which an enzyme acts
  33. Transition state
    The structure that forms transiently in the course of a chemical reaction and has the highest free energy of any reaction intermediate. 
  34. Turnover number(k_cat)
    A rate constant that is equal to the number of substrate molecules processed per enzyme molecule each second
  35. x-ray crystallography
    A technique for determining the 3-D structure of macromolecules by passing x-rays through a crystal of the purified molecules and analyzing the diffraction pattern of x-rays is used to determine the arrangement of individual atoms within a molecule
Card Set
BioE 220 Chapter 4
BioE 220 Vocab