Biology 1st Edition by Jerome Krueger, Kendra Hill, Robert Noyd

تمرين 13

Dental plaque is actually a type of biofilm formed by bacteria colonizing and attaching themselves to the surface of the teeth. If not removed within 48 hours, the plaque begins to harden into tartar, which is rock hard and difficult to remove. Bacteria in dental plaque live in a protected environment with little oxygen and produce lactic acid that can lead to gum disease and tooth decay. (a) How does forming a biofilm adapt oral bacteria to survive in the mouth? (b) Where do these bacteria acquire the nutrients to provide energy and raw materials to grow and reproduce? (c) Which environmental factors in the mouth favor the growth of oral bacteria? (d) Which metabolic process do oral bacteria use to produce energy? (e) Explain how brushing and flossing prevent tooth decay.