Chem 13H Elements of Life Posters 2004

Technetium, the first manmade element, can be obtained from the decay of Molybdenum, and is used as a radiation source in medical imaging. It is introduced into the body via intravenous injection. Technetium emits gamma radiation at an energy level of 140 keV. Images are obtained by using a scintillation camera, which converts radiation to electrical energy. The electrical signals are deciphered by a computer. Gammaphotographs display a sharp contrast between high and low levels of radiation exposure. Technetium radiopharmaceuticals are attracted to calcium, which is found in areas of bone fracture of new growth. Technetium is the most commonly used radiation source in modern medical imaging.

Insulin is the body’s chemical produced in the pancreas that regulates the transport of glucose. It is a major factor in magnesium absorption into cells as well. However, a deficiency in magnesium can actually cause resistant insulin. This could be due to the fact that insulin requires a process called tyrosine-kinase that requires magnesium. The resistance causes an increase in insulin release, causing the magnesium to be transported into the cells. However, this ruins the concentration balance between intracellular and extracellular magnesium. This causes a vicious cycle. As more magnesium is removed from the blood stream, the deficiency appears to increase and more insulin is released into the blood stream. Some researchers are now suggesting that magnesium deficiency could play a role in diabetes.Glucagon is insulin’s “other half”. While insulin promotes transport glucose, glucagon promotes production of glucose and break down of glycogen. If a lot of insulin is released, less glucagon is released. Research suggests that magnesium deficiency could be the cause of chronic fatigue syndrome. So far, researchers think magnesium is necessary for several steps of glucose break down in order to retrieve energy. However, others believe magnesium regulates glucagons. In either case, magnesium is extremely important to our body’s energy retrieval and storage.

Calcium acts as an ion messenger within the body. It plays an important role in membrane potential, which in turn affects muscle contraction and relaxation. Calcium, (as Ca2+) flowing through a charged channel, binds to a regulatory protein called troponin. This causes contraction of the heart, which causes the heart to pump blood throughout the body. When calcium unbinds from troponin, the cardiac muscle relaxes. The actual travel of calcium, its binding to troponin, and how it causes the heart to contract will be discussed.

Zinc plays an essential role in cell activities, through its coordination with many types of proteins (e.g., zinc finger proteins). Generally, uncoordinated Zn²⁺ ions pose a serious threat to cells, but it appears that weakly coordinated zinc plays an important (if mysterious) role in the central nervous system, through its presence in vesicles near the synapses of some neurons. These zinc-containing neurons appear almost exclusively in the cerebral cortex, suggesting that they may be important for cognitive function. This poster presents some of the techniques used to detect and study zinc-containing neurons as well as possible mechanisms for the transfer of zinc in synapses, both under normal conditions and as a cause of excitotoxicity in pathological conditions.

I will focus on the membrane potential, which is the transmembrane electrical potential difference expressed inside with respect to outside. The topic includes how to measure the membrane potential, the basic idea of why membrane potentials occur, and how the current flowing into and out of the cell which is carried by ions, both positive ions and negative ions.My specific example will be the resting channels in glial cells that are selective only for potassium which I will show how using the Nernst equation which is the one can determine mathematically.In a presentation, I will discuss how the Nernest approached to ions to get the membrane potential and what technique is used to get the equation explains the membrane potential.

Potassium Ions on the Move

Monique Maslak
Potassium

Cell membranes are effective barriers for small ions. Yet, rapid changes in concentrations of potassium and sodium ions inside cells are responsible for many critical biological processes such as sending nerve signals or muscle contractions. Potassium channels are trans-membrane proteins that allow for rapid and selective movement of potassium ion across the membrane with exclusion of smaller ions, such as sodium. The structure of such channels and their filtering and gating action will be described.

Breathing in Space

Christopher Haggerty
Lithium

The build up of carbon dioxide in space shuttles, and even space suits can be a problem for astronauts.  Fortunately, lithium hydroxide compounds act on the excess CO2 via an exchange reaction, resulting in the formation of lithium carbonate and the removal of the carbon dioxide from circulation.  This compound is kept in canisters on board the space shuttle, or in the pack of the spacesuit, and filters the air as it passes through, removing the carbon dioxide.  This technology is not limited to space travel, but can be used in submarines, or in other low pressure situations.

Sulfur has been discovered to impact the atmospheric conditions of the earth and the biogeochemistry of the oceans, involving cyclic processes that depend upon both environments. One important sulfur-containing compound involved in these cycles is dimethylsulfide (DMS). DMS is a gas released from the ocean surface that interacts with common substances in the atmosphere such as carbon dioxide. This interaction can exert a cooling effect upon climate, which in turn, influences the cycling and availability of such gases. This has a tremendous impact upon ocean surface organisms that are critical to the sulfur cycles. The chemical basis for these sulfur cycles will be examined.

Iron in Bacteria Reproduction

Ryan Urbanski
Iron

An important function of iron in the human body is to facilitate thetransfer of oxygen from lung cells to tissue cells through the use ofhemoglobin bonding.  While a certainlevel of dietary iron intake is necessary for this process to occur, too much ironwill have a negative effect on the body by promoting the growth of harmfulbacteria cells.  Specifically, thispresentation will examine the role of iron in ferrichrome, the molecule thatenables bacteria replication.

Cobalt 60 teletherapy is a popular method of treating cancer with using surgery. The tumor is bombarded with radiation emitted by the decay of ⁶⁰Co into ⁶⁰Ni through the following reaction: Co(60) --> Ni(60) + -1e + gamma rays. The radiation interacts with water atoms in the cell through a Compton interaction to form free radicals that attack the cancer cells. Cobalt 60 units are being replaced by more powerful systems in well-developed countries but are still important for treating cancers close to the skin. I will be discussing how the cobalt 60 units work and pros and cons of using such a machine to treat cancer.

Function and Formation ofNickel-Containing Enzymes

Matthew D. Litke
Nickel

Nickel-containing enzymes play important roles in several biologicalprocesses.  Two key enzymes are[Ni-Fe] hydrogenase and CO dehydrogenase.  In both enzymes nickel constitutes partof the enzymes’ active sites. [Ni-Fe] hydrogenase takes part in themetabolism of molecular hydrogen, and CO dehydrogenasecatalyzes the oxidation of carbon monoxide to carbon dioxide.  Both processes are central to thefunctioning of various microorganisms. The role of these enzymes in their respective reactions, as well as therelation of enzyme structure to these roles, will be explored.

Crustaceans, just like humans, need oxygen in their blood to sustain life. Instead of the hemoglobin found in red blood cells of humans, crustaceans have a protein called hemocyanin that exists freely in the blood. The copper bonds with oxygen and transports it through the blood stream to the organs of the body needing oxygen to function properly. A copper ion acts as the transition metal at the center of the complex surrounding. Copper is more easily bonded with oxygen as compared to the iron in humans, which is convenient for the lower oxygen surroundings crustaceans face as marine animals. The hemocyanin, when bonded with oxygen, creates a blue pigment. Therefore, crustaceans appear blue because of the pigment of their blood.

Manganese is often overlooked as an essential mineral in the human diet. It helps the body utilize many vitamins, such as C, B1, biotin, and choline and acts as an antioxidant. Manganese also helps the body in the production of body fat, sex hormones, and breast milk for females. The toxicity of Manganese is also overlooked, where high levels of Manganese in the blood leads to a serious health condition known as "manganese madness" characterized by severe psychiatric sypmtoms. The role of manganese in this condition will be described.

Chromium Complexes and Diabetes

ChadKuny
Chromium

Chromium(III) is believed to play a role in insulinsignaling. An oligopeptide with four chromium ions, chromodulin binds to activated insulin receptors and keeps themopen. This amplifies the insulin response to high blood sugar. Conflictingresearch has tentatively shown supplemental chromium to help insulin resistancein Type 2 diabetes. While much is still uncertain in this area, I will explainthe current state of research and what chemical characteristics of chromiumcome into effect in this mechanism.