About.com Biology

Viruses May Help Stop Bacterial Infections

Sat, 21 Nov 2009 05:00:57 +0000


Bacteriophage Structure © Gary E. Kaiser

Viruses are unique organisms that can infect humans, plants and even bacteria. Texas A&M University researchers are exploring the possibility of using knowledge gained from bacteriophages (bacteria infecting viruses) to help fight bacterial infections in humans.

A single virus particle (virion) is in and of itself essentially inert. It lacks needed components that cells have to reproduce. Once a virus has infected a cell, it will "marshal" the cell's ribosomes, enzymes and much of the cellular machinery to reproduce. Viral reproduction produces many progeny, that when complete, leave the host cell to infect other cells in the organism. In order for the newly formed bacteriophages to be able to leave the host cell, they must penetrate the bacterial cell wall.

The researchers in this study have determined the specific enzyme that is responsible for the destruction of the cell wall. Researcher Sun Qingan states, "This finding enables us to better understand the release process and provides us with a possible target when we want to control the destruction of bacteria cell walls or prohibit this action in some infectious diseases." The enzyme, R12, breaks down the bacterial cell wall from inside the cell causing the bacterium to split open.

Learn more about this discovery:

How Viruses Destroy Bacteria Science Daily

Viruses May Help Stop Bacterial Infections originally appeared on About.com Biology on Saturday, November 21st, 2009 at 05:00:57.

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Bacteria in Cigarettes

Fri, 20 Nov 2009 10:00:05 +0000


Photo courtesy Photos8.com

According to a study to be published in the journal Environmental Health Perspectives, researchers have discovered that cigarettes contain hundreds of different types of bacteria. This is another in a long line of reasons to avoid cigarette and other tobacco use. Cigarette smoking is known to cause various health problems such as cancer, cardiovascular disease and respiratory disease.

In the study, four different cigarette brands were tested and found to contain hundreds of bacteria species ranging from those found in the soil to bacteria that cause disease in humans. Lead researcher Amy Sapkota states, "If these organisms can survive the smoking process, and we believe they can, then they could possibly go on to contribute to both infectious and chronic illnesses in both smokers and individuals who are exposed to environmental tobacco smoke." The next step in the research process is to determine if these bacteria can in fact survive the smoking process and cause or contribute to human diseases.

Learn more about this discovery:

Cigarettes Harbor Many Pathogenic Bacteria Science Daily

Bacteria in Cigarettes originally appeared on About.com Biology on Friday, November 20th, 2009 at 10:00:05.

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Bacterial Rope Builders

Wed, 18 Nov 2009 14:02:32 +0000


Microscopic view of ropes built in culture by cyanobacteria. Arizona State University

Researchers have discovered that some bacteria, known as cyanobacteria, have acquired the ability to build rope-like structures to prevent soil erosion. Cyanobacteria are typically found in areas such as sandy desert soils, coastal sand flats and various marine and fresh water environments. They often grow in large colonies and produce nitrogen in the soil that is important for plant growth.

Cyanobacteria found in the sandy desert soils of the Colorado Plateau have evolved to develop the ability to grow in thick cords that extend to a few inches in length. This size enables the cyanobacteria to hold onto sand grains that would otherwise be blown or washed away. While this ability may reduce the microbe's access to light or nutrients, it also stabilizes the soil and promotes colonization by various other microbes.

Learn more about this discovery:

Bacterial Ropes Tie Down Shifting Southwest Science Daily

Bacterial Rope Builders originally appeared on About.com Biology on Wednesday, November 18th, 2009 at 14:02:32.

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Wireless Phones Affect the Brain

Sat, 14 Nov 2009 05:00:33 +0000


FreeDigitalPhotos.net

Research studies have shown that cell phone and other wireless phone use affects the brain. Radiation from these phones causes levels of a protein called transthyretin to rise in the blood. This protein is found in the choroid plexus (blood-brain barrier) which separates blood from cerebrospinal fluid in the brain. This barrier protects the brain from harmful substances in the blood.

While the researchers can't say for certain that wireless phone use produces any health risks, they caution against excessive use, especially in children and teens. The effects of long-term exposure to wireless phone radiation have yet to be determined. What we do know is that microwaves from these types of phones definitely have a biological impact on the brain.

Learn more about this discovery:

Wireless Phones Can Affect The Brain Science Daily

Wireless Phones Affect the Brain originally appeared on About.com Biology on Saturday, November 14th, 2009 at 05:00:33.

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Dark Chocolate Reduces Stress

Fri, 13 Nov 2009 08:00:26 +0000


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More good news for chocolate lovers: researchers have discovered that eating dark chocolate can reduce stress and change the body's metabolism. As a caution to those who have a tendency to consume a little too much chocolate, it only takes about an ounce and a half of dark chocolate a day to trigger a reduction in stress hormone levels. It is best to consume dark chocolate in moderation as it does contain a fair amount of calories.

This is just the latest in a string of discoveries about the beneficial effects of eating chocolate. Previous studies have shown that chocolate acts as an antioxidant, reduces blood pressure, increases blood flow to the brain, and even acts a painkiller. Researchers have also found that cocoa beans, which are used to make chocolate, contain antibacterial agents that can help fight tooth decay.

Learn more about this discovery:

Dark Chocolate Helps Ease Emotional Stress Science Daily

Dark Chocolate Reduces Stress originally appeared on About.com Biology on Friday, November 13th, 2009 at 08:00:26.

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Animal Cells

Wed, 11 Nov 2009 14:04:46 +0000


Normal Uterine Cells National Cancer Institute

Animal cells are eukaryotic cells, which are cells that have a membrane-bound nucleus. Unlike in prokaryotic cells, where the genetic material is not separated from the rest of the cell, animal cells contain a nucleus that houses the cell's DNA.

In addition to the nucleus, animal cells also contain other membrane-bound organelles, or tiny cellular structures, that carry out specific functions necessary for normal cellular operation. Organelles have a wide range of responsibilities that include everything from producing hormones and enzymes to providing energy for animal cells. Some examples of organelles that are found in typical animal cells include:

Another characteristic of animal cells is that most are diploid, meaning that they have a full complement of genetic material consisting of homologous chromosome pairs. In other words, diploid cells contain two sets of chromosomes (one chromosome donated from each parent). Not all animal cells however are diploid. Animal reproductive cells, also called gametes, are haploid cells. Haploid cells contain only one set of chromosomes.

More About Animal Cells:

Animal Cells originally appeared on About.com Biology on Wednesday, November 11th, 2009 at 14:04:46.

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DNA Structure

Sat, 07 Nov 2009 05:00:30 +0000


DNA Double Helix NASA

With the popularity of many crime scene investigation shows, DNA has become a household term. It is the basic building block for our genetic structure and contains all the information needed for growth, development and reproduction. With the exception of identical twins, each person's DNA is unique. So, what exactly is DNA? DNA or deoxyribonucleic acid is a type of macromolecule known as a nucleic acid. It is shaped like a twisted double helix and is composed of long strands of alternating sugars and phosphate groups, along with nitrogenous bases (adenine, thymine, guanine and cytosine). DNA is organized into chromosomes and housed within the nucleus of our cells.

Learning about DNA can be interesting and fun. Constructing DNA models is a great way to learn about DNA structure, function and replication. You can also discover how to extract DNA from a banana or make a candy DNA model.

DNA Structure originally appeared on About.com Biology on Saturday, November 7th, 2009 at 05:00:30.

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Learning Language in the Womb

Fri, 06 Nov 2009 16:16:21 +0000


Image: Canwest News Service

Did you know that babies learn elements of language before they are even born? While still in their mother's womb, fetuses can memorize sounds and melodies in both music and language. Researchers have now discovered that babies reproduce intonations of language patterns that they have memorized while in the womb.

This study centered around the analysis of crying melody patterns of French and German infants. It was discovered that French newborns produce rising crying patterns, while German newborns produce falling crying patterns. As researcher Angela Friederici explains, "In French, a lot of words have stress at the end, so that the intonation rises, while in German, it is mostly the opposite." This study shows that newborns produce sounds with intonation patterns that are familiar. Evidence from additional studies also suggests that by the time a baby reaches four months old, intonations of the mother tongue are firmly fixed in the brain.

Learn more about this discovery:

Language Learning Starts From The Womb Science Daily

Learning Language in the Womb originally appeared on About.com Biology on Friday, November 6th, 2009 at 16:16:21.

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Army Ant Adoption

Wed, 04 Nov 2009 16:52:41 +0000


Soldier Army Ants Image: Daniel Kronauer/Harvard University

In army ant colonies everything begins and ends with the queen. The queen produces eggs that develop into soldiers or workers. The worker ants forage for food and take care of the queen's brood, while the soldier ants defend the colony. When the queen dies, the colony vanishes. Researchers from the Harvard Museum of Comparative Zoology and the University of Copenhagen have determined what happens to army ant colony members once the queen is gone.

It appears that individual ants from most queenless colonies are incorporated into nearby colonies rather than killed. Of the ten queenless colonies studied, seven were adopted into other colonies. One colony remained on its own and produced a small number of winged males with the ability to venture off to find young queens.

Learn more about this discovery:

Orphan Army Ants Adopted Harvard University

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Army Ant Adoption originally appeared on About.com Biology on Wednesday, November 4th, 2009 at 16:52:41.

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Pumpkin Rinds Inhibit Microbes

Fri, 30 Oct 2009 13:00:43 +0000


FreeDigitalPhotos.net

Pumpkins are not just good for making Jack-o'-Lanterns or pumpkin pie. Researchers revealed that pumpkin rinds contain proteins that inhibit the growth of microbes. These antimicrobial proteins could be used to develop treatments for fungal diseases that effect humans and plants.

In the study, pumpkin rind proteins were shown to restrict the growth of the fungus that induces vaginal yeast infections and diaper rash. Another encouraging discovery was that treating the fungus with the pumpkin protein appeared to cause no toxic effects. The protein was also effective at prohibiting fungal growth in plant crops.

Learn more about this discovery:

Pumpkin Skin May Scare Away Germs Science Daily

Pumpkin Rinds Inhibit Microbes originally appeared on About.com Biology on Friday, October 30th, 2009 at 13:00:43.

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