Exam 2: The Chemical Basis of Life

Reactions in which a proton may participate include:

Which lipid is most likely to remain solid at room temperature?

Which of these factors or observations provide explanations of how the self-assembly of complex structures such as ribosomal subunits can be achieved more efficiently within cells than in vitro? (Select all that apply)

Biological roles for carbohydrates include: (Select all that apply)

In a cell, where are strong ionic bonds most likely to be found?

A buffer has all of the following characteristics EXCEPT:

Which of these statements regarding glyceraldehyde is NOT correct?

Inert biological molecules like fats and waxes are chemically characterized by possessing many:

Many so-called temperature-sensitive mutations have been discovered in a wide variety of organisms. These are proteins that are non-functional at higher temperatures, while, at lower temperatures (often just a few degrees lower), they function normally. For example, the coloration patterns in Siamese Cats arise from a temperature-sensitive mutation. An enzyme required for the synthesis of dark pigment is unable to function in areas close to the body where normal physiological temperatures prevail. However, at the tips of the ears, paws, the tip of the tail and other extremities where the temperature is slightly lower, the enzyme works correctly and dark pigment is produced. What is happening at the molecular level that explains this?

The endosymbiotic theory proposes that bacteria were engulfed by ancestral eukaryotic cells and sheltered within their cytoplasm whilst providing a survival advantage to the eukaryotic cell as well. Mitochondria and chloroplasts, now organelles, possess DNA with sequence homology to rickettsia and cyanobacteria, respectively. Which of the choices below best describes an organelle-like structure with a similar beneficial relationship when considering plant growth in nitrogen-limited soils?

The nucleic acid precursor comprising one nitrogenous base and one sugar is known as a:

If a polypeptide is 100 amino acids long, and could be made of any of the 20 amino acids in any order, what is the total number of possible variations for this polypetide?

Which of the groups participates exclusively in hydrophobic interactions?

Which statements regarding mad cow disease and Alzheimer's disease are CORRECT? (Select all that apply)

The historic meaning of an organic molecule was that the molecule was derived from a living organism and contained carbon. Today we call such molecules __________________.

Which of these molecules have been observed to play a role in eukaryotic RNA/protein interaction where aqueous phase separation is being studied? (Select all that apply)

In a phospholipid, the end of the molecule likely to face towards a nonpolar environment is ________________.

Examine the structures of cholesterol, testosterone and estrogen shown in Figure 2.23 (Or provide the figure for the Q). If we know that cholesterol is the precursor for synthesizing the other sex hormones, which of the statements below is likely to be CORRECT?

Which element can only be obtained by plants through mineral uptake, rather than via atmospheric fixation by the plant or its symbiont?

What type of protein secondary structure is characterized as being highly extensible because of its coiled structure?