Regina's Biology Blog

Proteins are very important molecules in our cells. They are involved in virtually all cell functions. Each protein within the body has a specific role. Some proteins are involved in structural support, while others are involved in bodily movement, or in defense against germs.

Proteins vary in structure as well as function. They are constructed from a set of 20 amino acids and have distinct three-dimensional shapes. Below is a list of a few types of proteins and their functions:

• Antibodies defend the body from germs.
  
• Contractile proteins are responsible for movement.
  
• Enzymes speed up chemical reactions.
  
• Storage proteins store amino acids.

To learn more about proteins, visit Protein Function.

Researchers have uncovered the key to the production of a specific type of fat called brown fat. Because brown fat generates heat by burning calories and releasing energy, it is hoped that this discovery can lead to new treatments for obesity. In the study, researchers identified the molecular switch responsible for the creation of brown fat. This switch, the PRDM16 gene, converts immature muscle cells into brown cells when activated.

There are two types of adipose (fat) tissue in the body; brown fat and white fat. White fat stores energy and helps to insulate the body, while brown fat burns energy and generates heat. Now that the PRDM16 gene has been identified, the focus now shifts to the development of drugs that can convert white fat into brown fat. Another possibility would be to develop a method for transplanting brown fat into the body to stimulate fat loss.

Learn more about this study, see:

• Making 'Good' Fat From Muscle And Vice Versa (Science Daily)

Body Planes

Anatomical directional terms are like the directions on a compass rose of a map. Similar to the directions, North, South, East, and West, they can be used to describe the locations of structures in relation to other structures or locations in the body.

These terms are very useful when describing the locations of structures to be studied in human anatomy classes and when performing dissections.

Anatomical directional terms can also be applied to the planes of the body. Imagine a person standing in an upright position. Now imagine dissecting this person with imaginary vertical and horizontal planes. Anatomical planes can be used to describe any body part or an entire body.

Muscle Cell Mitochondria © Dennis Kunkel

Mitochondria are the cell's power producers. They convert energy into forms that are usable by the cell. They are the sites of cellular respiration which ultimately generates fuel for the cell's activities. The number of mitochondria in a cell can range from a few to several thousand, depending on the type of cell.

Mitochondria are tubular or oblong shaped and are bounded by double membranes. The double membranes divide the mitochondrion into two distinct parts: the intermembrane space and the mitochondrial matrix. Mitochondria are semiautonomous in that they can divide and grow to make more of themselves. They also have their own DNA and ribosomes. To learn more about mitochondria and other cellular components, visit Journey into the Cell.

Researchers have discovered how Strep bacteria are able to survive and spread throughout the body. The bacteria produce a substance, SpyCEP, that inhibits the ability of immune system cells to respond to an infection. SpyCEP (Strep. pyogenes cell envelope protease) interferes with the production of a certain molecule in the body that sends signals to white blood cells when there is an infection. As a result, the bacteria go undetected until it is too late and the infection spreads.

In the study, the researchers isolated the Strep bacteria and removed the gene responsible for producing SpyCEP. They discovered that without the ability to produce SpyCEP, white blood cells were able to detect and destroy the bacteria. The study was conducted with group A Streptococcus bacteria. This pathogen strain is responsible for several types of diseases including strep throat and "flesh-eating disease."

Learn more about this study, see:

• How Flesh-eating Bacteria Attack The Body's Immune System (Science Daily)

If you are taking a biology course, at some point you will have to do lab experiments. This means that you will also have to complete biology lab reports. You may be thinking, how do I write a good lab report or why do I need to write a lab report at all?

The purpose of writing a lab report is to determine how well you performed your experiment, how much you understood what happened during the experimentation process, and how well you can convey that information in an organized fashion. A good lab report has a format that includes five main sections. They are the introduction, methods and materials, results, discussion and conclusion, and citation.

Keep in mind that an individual instructor may have a specific format that he or she requires you to follow. Please be sure to consult your teacher about the specifics of what to include in your lab report. Also remember that lab reports are individual assignments. You may have a lab partner, but the work that you do and report on should be your own.

Photo courtesy PDPhoto.org

Many people realize the importance of staying fit and eating healthy. Organic foods have long been touted as being more nutritious than foods that are treated with chemicals or pesticides. If you have ever compared the prices of the two types of food at the grocery store, you know that organic foods are certainly more expensive. The question becomes, are organic foods really better for you?

Studies conducted by researchers from the Department of Human Nutrition, University of Copenhagen, suggest that organic foods are no more nutritious than foods grown with pesticides. Three different types of cultivation methods were used in the study. One method involved growing vegetables and fruits with low nutrient inputs and no pesticides. The second method involved treating the food with pesticides and adding low nutrient inputs in the soil. The third method involved using high nutrient inputs along with pesticides.

After harvesting and analyzing of the food, the researchers found no difference in nutritional content between the organically grown and traditionally grown foods. In fact, the only major difference between the crops was that the organically grown crops yielded much less produce.

Learn more about this study, see:

• Organic Food Has No More Nutritional Value Than Food Grown With Pesticides, Study Shows (Science Daily)

Photo courtesy PDPhoto.org

Whether fair or unfair, most people make judgments about others based on appearance. Scientists believe that people determine the intentions of others by looking at their face and facial expressions. In fact, one quick glance at a person's face is all it takes to influence how you feel about them.

With the help of a computer program, scientists from Princeton University have determined the types of faces people consider to be trustworthy or untrustworthy. Characteristics of a trustworthy face include a U-shaped mouth and upturned eyebrows. Characteristics of an untrustworthy face include lips that are curled at the edges and eyebrows that are turned down.

It was also determined that people make evaluations about dominance based on facial observations. If you have a squared, broad chin, you have a characteristic of a dominant person. People with baby face characteristics are considered to be least dominant.

Scientists believe that face-seeking is a hard-wired phenomena in humans. There is also speculation that the brain contains a special mechanism that is used for evaluating faces.

Learn more about this study, see:

• Whom Do We Fear Or Trust? (Science Daily)

Image courtesy of Carolina Biological Supply/Access Excellence

Blood vessels are intricate networks of hollow tubes that transport blood throughout the entire body. There are several types of blood vessels:

• Arteries - elastic vessels that transport blood away from the heart.
  
• Veins - elastic vessels that transport blood to the heart.
  
• Capillaries - extremely small vessels located within the tissues of the body that transport blood from the arteries to the veins.
  
• Sinusoids - extremely small vessels located within the liver, spleen and bone marrow.

Blood travels from the heart via arteries to smaller arterioles, then to capillaries or sinusoids, to venules, to veins and back to the heart. This continuous cycle of blood flow is known as the cardiac cycle.

Migratory Wildebeest in the Serengeti Photograph: Nathan Gregory

Scientists have discovered a disturbing trend among migratory animals. It appears that animal migration is in severe decline all over the world. In some cases, animal migration has ceased altogether.

What are the causes for the decline in migration? They can be narrowed down to four main threats. They are the destruction of habitat, the erection of obstructions, over exploitation, and change in climate.

Scientists believe that the decline in migration is a significant issue due to the impact that migrating animals have on other animals and the environment.

Let's consider wildebeest for example. They play an important ecological role in the Serengeti. They are herbivores that consume large quantities of vegetation and redistribute nutrients through the expulsion of waste. They also provide food for the many predators of the Serengeti. If these migrating animals were to decline in great numbers, there would be severe consequences for the animals and vegetation of the Serengeti.

Learn more about this study, see:

• Going, Going, Gone: Is Animal Migration Disappearing (PLoS Biology)
  Wilcove DS, Wikelski M (2008) PLoS Biol 6(7): e188