Functions of enzymes include all of the following except __________.

Which of the following would most greatly increase the activity of an enzyme functioning in the small intestine?

Carbonic anhydrase exhibits typical enzyme kinetics expected of similar enzymes. Which of the following is the quantity described by the value Km?

Scientists use a process called Flourescent In-Situ Hybridization, or FISH, to study genetic disorders in humans. FISH is a technique that uses spectrographic analysis to determine the presence or absence, as well as the relative abundance, of genetic material in human cells. 

To use FISH, scientists apply fluorescently-labeled bits of DNA of a known color, called probes, to samples of test DNA. These probes anneal to the sample DNA, and scientists can read the colors that result using laboratory equipment. One common use of FISH is to determine the presence of extra DNA in conditions of aneuploidy, a state in which a human cell has an abnormal number of chromosomes. Chromosomes are collections of DNA, the totality of which makes up a cell’s genome. Another typical use is in the study of cancer cells, where scientists use FISH labels to ascertain if genes have moved inappropriately in a cell’s genome.

Using red fluorescent tags, scientists label probe DNA for a gene known to be expressed more heavily in cancer cells than normal cells. They then label a probe for an immediately adjacent DNA sequence with a green fluorescent tag. Both probes are then added to three dishes, shown below.  In dish 1 human bladder cells are incubated with the probes, in dish 2 human epithelial cells are incubated, and in dish 3 known non-cancerous cells are used. The relative luminescence observed in regions of interest in all dishes is shown below.

Cancer cells often invade by breaking through the collagen of a basement membrane of epithelial tissue. Considering the composition of basement membranes, which of the following compounds is most likely to be used by cancer cells for this purpose?

Which amino acid has a side chain that can form covalent bonds?

A supercoiled helix is described by which level of peptide structure?

Disulfide linkages are connections made between polypeptide chains to increase the cohesion of a protein. These bonds fall into the category of __________.

Pepsin is an enzyme found within the stomach. As a physiologist you are setting up an experiment to study the properties of pepsin. You place pepsin enzymes into a solution and notice that the pH of the solution is 4. 

Which of the following would you add in order to maximize the enzyme's ability to function normally?

The functional properties of an enzyme are dependent on the pH of the body as well as temperature. Each protein has specific conditions at which it will function optimally. These conditions can help predict where a protein will be found in the body.

In what area of the cell would you expect to find an enzyme that functions best in acidic conditions?

In 2013, scientists linked a cellular response called the unfolded protein response (UPR) to a series of neurodegenerative diseases, including such major health issues as Parkinson’s and Alzheimer’s Disease. According to their work, the unfolded protein response is a reduction in translation as a result of a series of enzymes that modify a translation initiation factor, eIF2, as below:

In the above sequence, the unfolded protein sensor binds to unfolded protein, such as the pathogenic amyloid-beta found in the brains of Alzheimer’s Disease patients. This sensor then phosphorylates PERK, or protein kinase RNA-like endoplasmic reticulum kinase. This leads to downstream effects on eIF2, inhibition of which represses translation. It is thought that symptoms of neurodegenerative disease may be a result of this reduced translation.

The enzyme PERK is a kinase. Which of the following is not true of all kinases?