An extremely large lactose source is encountered by an E. coli cell in the lumen of the small intestine of a human who just ate an entire carton of ice cream. Which of the following would most likely be a contributor to why the E. coli does not metabolize any of the lactose?

#Question id: 381

#Unit 1. Structure and Function of Biomolecules

Consider an acetate buffer, initially at the same pH as its pKa (4.76). When sodium hydroxide (NaOH) is mixed with this buffer, the:

#Question id: 382

#Unit 1. Structure and Function of Biomolecules

The molar ratio of sodium acetate to acetic acid in a buffer solution with a pH OF 5.76 is 10:1. Assuming the total buffer concentration is 2.2 X 10^-2 mol/L, how many grams of sodium acetate (m.w. 82) and how many grams of acetic acid (m.w. 60) should be used in preparing a litre of the solution?

#Question id: 383

#Unit 1. Structure and Function of Biomolecules

Three buffers are made by combining a 1 M solution of acetic acid with a 1 M solution of sodium acetate in the ratios shown below

 Which of these statements is true of the resulting buffers?

#Question id: 384

#Unit 1. Structure and Function of Biomolecules

A solution was prepared by dissolving 0.02 moles of acetic acid (HOAc; pKa = 4.8) in water to give 1 liter of solution. What is the pH? To this solution was then added 0.008 moles of concentrated sodium hydroxide (NaOH). What is the new pH? (In this problem, you may ignore changes in volume due to the addition of NaOH).

#Question id: 385

#Unit 1. Structure and Function of Biomolecules

In which reaction below does water not participate as a reactant (rather than as a product)?

#Question id: 386

#Unit 1. Structure and Function of Biomolecules

Which of the following properties of water does not contribute to the fitness of the aqueous environment for living organisms?