Exam 2: Essential Chemistry for Biology

Sugar dissolves when stirred into coffee. The coffee is the ________, the sugar is the ________, and the sweetened coffee is the ________.

Scenario While radioactive isotopes are used in medicine to identify tumors and other diseases, they can also be used to treat diseases such as cancer. One method to treat cancerous tumors is to expose them to radiation which can kill the cancerous cells and the tumor. In 2013, the U.S. Food and Drug Administration approved a new cancer treatment based on the radioactive isotope radium-223; this isotope has a half-life of 11.4 days. The radioactive drug, known as Xofigo®, is injected into the patient's bloodstream and travels to certain regions of the body. Because it emits high-energy radiation over short distances, it can kill cancerous cells in the sites where it localizes. After the drug was injected into a person, the following data were collected regarding the amount of radiation measured in different organs in the person's body. -A cancer patient receives an injection of the drug on March 1. Suppose that the patient must receive a second injection once the amount of the drug decreases to less than 6% in his or her body. On approximately what day should the cancer patient schedule an appointment to receive another injection?

The data below are from three separate studies that tested different treatment options for prostate cancer. What can you conclude from these data?

The graph below shows data regarding radioactive decay of carbon-14. If decay continues to occur normally, how much C-14 will remain after 22,800 years?

Beryllium's atomic mass is 9, and its atomic number is 4. How many protons are found in a beryllium atom?

The data below are from three separate studies that tested different treatment options for prostate cancer. Based on these data you might conclude that after 10 years, radioactive seeds are a more effective treatment option than external radiation for prostate cancer. What is a possible confounding factor that could lead to the results below?

What are the four most common elements found in living organisms?

Some tiny insects are able to walk on water. Why?

Scenario Please read the following scenario to answer the following questions. The last few miles of the marathon are the most difficult for Heather. Her hair is plastered to her head, sweat clings to her arms, and her legs feel as if they had nothing left. Heather grabs a cup of ice water. The ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. Then a breeze kicks up and she finally feels some coolness against her skin. Drops of sweat, once clinging to her forehead, now spill down, and Heather feels a stinging as the sweat flows into her eyes. -When Heather grabbed the glass of ice water, the ice cubes were floating at the top. Why were the ice cubes floating in the water?

How many oxygen atoms are in the products of the following reaction? C₆H₁₂O₆ + 6 H₂O + 6 O₂ → 6 CO₂ + 12 H₂O