A mutation in an E. coli cell becomes active half-way through a round of replication. The cell completes the round of replication normally but then cannot start a second round. Which protein could be mutated?

#Question id: 382

#Unit 1. Molecules and their Interaction Relevant to Biology

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. Molecules and their Interaction Relevant to Biology

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. Molecules and their Interaction Relevant to Biology

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: 386

#Unit 1. Molecules and their Interaction Relevant to Biology

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

#Question id: 387

#Unit 1. Molecules and their Interaction Relevant to Biology

For a weak acid with a pKa of 6.0, What would be the ratio of acid to salt at pH 5.

#Question id: 389

#Unit 1. Molecules and their Interaction Relevant to Biology

A weak acid HA has a pKa of 5.0.  If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?