Stem cells are defined by two capacities:

(1) the ability to regenerate or “self-renew” and

(2) the ability to differentiate into all diverse cell types. Embryonic stem cells have the capacity to generate every specialized cell type in an organism, in other words,

#Question id: 366

#Unit 1. Molecules and their Interaction Relevant to Biology

What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-10 M?

#Question id: 365

#Unit 1. Molecules and their Interaction Relevant to Biology

Water is a polar molecule: the oxygen atom with its unshared electrons carries a partial negative charge (δ−) of ___________, and the hydrogen atoms each carry a partial positive charge (δ+) of __________, where e is the charge of the electron.

#Question id: 364

#Unit 1. Molecules and their Interaction Relevant to Biology

 A solution contains 0.0000001 (10-7) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution?

#Question id: 363

#Unit 1. Molecules and their Interaction Relevant to Biology

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4? If 1.0 mL of 10.0 M NaOH is added to a liter of the buffer prepared, how much will the pH change? (pKa = 6.86)

#Question id: 362

#Unit 1. Molecules and their Interaction Relevant to Biology

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

#Question id: 361

#Unit 1. Molecules and their Interaction Relevant to Biology

Calculate the percentage of histidine that has its imidazole side chain protonated at pH 7.3. The pKa values for histidine are pK1 = 1.8, pK2 (imidazole) = 6.0, and pK3 = 9.2.