Actual coverage will always differ somewhat from what is printed here. Thomas M. Terry Cell wall Rigid layer, preserves shape when rest of cell is digested. 3.20-3.29 in texts. View effects of penicillin on bacteria Structural Basis for the Gram Stain Christian Gram recognized two different types of bacteria based on reaction to certain staining procedure. OM is porous because of porin proteins that create pores, allow small molecules to pass freely.
Water flows in, presses against wall.
Effects of lysozyme and pencillin Growing cell must break peptidoglyan at certain spots, insert new material, seal back together to grow new wall Cell wall contains bacterial enzymes called autolysins to make these breaks, but carefully controlled. Mechanism not well understood. Found in animal secretions, e.g. tears, saliva, mucous membranes. Challenge Question Spheroplasts, Protoplasts L- forms, and Mycoplasmas Lysozyme and penicillin can lead to cells without walls. Still able to live if isotonic, but will lyse if put in hypotonic environment.