Joan uses a model to show how wood burns at the level of atoms and molecules. Her model tracks 840 carbon atoms that make up a small fraction of a wood sample. The table shows how the carbon atoms are converted into carbon dioxide as the wood burns over time. Which of the claims about the burning of wood is supported by Joan’s model? Select all the claims that are supported.
A. Matter is conserved during the burning of wood.
B. Chemical energy is conserved during the burning of wood.
C. Burning wood involves a series of chemical reactions that occur in one direction only.
D. Burning wood involves a series of chemical reactions that occur in both the forward and reverse directions.
E. Burning wood involves oxygen as well as carbon.

Penicillin is hydrolyzed and thereby rendered inactive by penicillinase (also known as β-lactamase), an enzyme present in some resistant bacteria. the mass of this enzyme in staphylococcus aureus is 29.6 kd. the amount of penicillin hydrolyzed in 1 minute in a 10-ml solution containing 10-9 g of purified penicillinase was measured as a function of the concentration of penicillin. assume that the concentration of penicillin does not change appreciably during the assay. penicillin(μm) amount hydrolyzed(nmol) 1 0.11 3 0.25 5 0.34 10 0.45 30 0.58 50 0.61 (a) plot v0 versus [s] and 1/v0 versus 1/[s] for these data. does penicillinase appear to obey michaelis-menten kinetics? if so, what is the value of km? (b) what is the value of vmax? (c) what is the turnover number of penicillinase under these experimental conditions? assume one active site per enzyme molecule.