Sexually transmitted diseases are a common problem among young people in the United States. One of the more common diseases is caused by the bacterium Neisseria gonorrhoeae, which leads to inflammation and purulent discharge in the male and female reproductive tracts.

The bacterium has a number of systems to evade host defenses. Upon infection, it uses pili to adhere to host epithelium. The bacterium also uses an enzyme, gonococcal sialyltransferase, to transfer a sialyic acid residue to a gonococcal surface lipooligosaccharide (LOS). A depiction of this can be seen in Figure 1. The sialyic acid residue mimics the protective capsule found on other bacterial species.

Once infection is established, Neisseria preferentially infects columnar epithelial cells in the female reproductive tract, and leads to a loss of cilia on these cells. Damage to the reproductive tract can result in pelvic inflammatory disease, which can complicate pregnancies later in the life of the woman.

What is likely true of the lipid A found on the glucosamine molecule in Figure 1?

Water is the solvent in which all chemical reactions take place for living organisms. In addition, water has a number of critical characteristics that allows it to be invaluable to life as we know it.

Which of the following statements is FALSE concerning the properties of water?

Drain cleaners are a common household staple, used to open clogged drains in bathtubs and sinks. Human hair is a common culprit that clogs pipes, and hair is made predominately of protein. Drain cleaners are effective at breaking down proteins that have accumulated in plumbing. Drain cleaners can be either acidic or basic, and are also effective at breaking down fats that have accumulated with proteins.

A typical reaction—reaction 1—which would be expected for a drain cleaner on contact with human hair, would be as follows in an aqueous solution:

Another reaction that may occur, reaction 2, would take place as follows in an aqueous solution:

The drain cleaner in Reaction 1 was used to break down fats as well as the protein depicted. How would the fats be most different in molecular structure?

Water often acts as a reactant or solvent in biological reactions. Which of the following cellular components would not be sufficiently solvated in the body?

Drain cleaners a common household staple, used to open clogged drains in bathtubs and sinks. Human hair is a common culprit that clogs pipes, and hair is made predominately of protein. Drain cleaners are effective at breaking down proteins that have accumulated in plumbing. Drain cleaners can be either acidic or basic, and are also effective at breaking down fats that have accumulated with proteins.

A typical reaction—reaction 1—which would be expected for a drain cleaner on contact with human hair, would be as follows in an aqueous solution:

Another reaction that may occur, reaction 2, would take place as follows in an aqueous solution:

In contrast to the proteins in Reactions 1 and 2, the body uses carbohydrates __________.

Which of the following accurately describes glucose?

Which of the following carbohydrates is created in animals, but not in plants?

Which of the following statements is true concerning glucose?

Which carbon in a carbohydrate determines whether a human is capable of digesting it properly?

Which type of bond is created between carbohydrates and the sidechain amine of select asparagine residues in proteins?