Andy is using a graduated cylinder to measure the volume of water. Which of the following are correct procedures for reading the volume of water in a graduated cylinder?

I.
He should hold the graduated cylinder in his hand so the surface of the water is at eye level.

II.
He should place the graduated cylinder on a flat surface and bend down so the surface of the water is at eye level.

III.
He should take the reading from the bottom of the curve of the surface of the water.

IV.
He should take the reading from the highest point of the surface of the water.

A.
II and IV only
B.
I and IV only
C.
I and III only
D.
II and III only

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.