This equation accounts for the kinetic data given in Figure 8-15.At very low substrate concentration, when [S] is much less than KM, V [s]Vmax/KMi that is, the rate is directly proportional to the substrate concentration At high substrate concentration, when [SI is much greater than KM, V=Vmax; that is, the rate is maximal, independent of substrate
1. Hemoglobin is a multisubunit allosteric protein that carries 02 in erythrocyte. 1.1 Hemoglobin is a well-studied and well-understood protein. 1.1.1 It was one of the first proteins to have its molecular mass accurately determined. 1.1.2 The first protein to be characterized by ultracentrifuge. 1.1.3 The first protein to be associated with a specific physiological function
1. General studies of the peptide bond 1.1 The peptide(O=C-N-H) bond was found to be shorter than the C-N bond in a simple amine and atoms attached are coplanar. 1.1.1 This was revealed by X-ray diffraction studies of amino acids and of simple dipeptides and tripeptides. 1.1.2 The peptide (amide) bond was found to be about 1.32 A (C-N single bond, 1.49; C= double bond, 1.27), thus having partial double bond feature (should be rigid and unable to rotate freely)
Biological Membranes and Transport Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates. Membranes define the external boundaries of cells and regulate the molecular traffic across that boundary In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and components
Chapter Amino Acids, Peptides, and Proteins 0. General Introduction Proteins are polymers(多聚体) of amino acids. -20 amino acids(氨基酸)→ millions of proteins with different properties and activities. Protein structures are studied at primary, secondary, tertiary and quaternary levels. -a helix, B sheets, globular, complexes, denaturation and folding. Proteins have widely diverse forms and functions
