Cell Structure and Function
Applying Cell Structure and Function
Bacteria are some of the most common organisms made of prokaryotic cells. People generally think of bacteria as dangerous, but most bacteria are harmless. Some bacteria are actually beneficial to humans and society. For example, a bacterium called Bifidobacterium animalis is a rod-shaped bacterium that can be found in the large intestines of most mammals, including humans. Part of the genus Bifidobacterium, these rod-shaped bacteria help maintain the body's digestive balance. They attach themselves to the wall of the large intestine, where they compete for food and space. A healthy body with a large colony of B. animalis has little room and few nutrients to spare for the harmful bacteria that may try to invade. They are also excellent producers of acids that reduce pH. This helps prevent harmful bacteria that thrive in basic environments from living and reproducing in the intestines.
Some kinds of bacteria are used to remove pollutants from contaminated areas. These bacteria are able to degrade hydrocarbons and use oil as their source of energy. In areas where oil is naturally present, communities of microbes are usually well-established and diverse. After the Deepwater Horizon oil spill in the Gulf of Mexico, naturally occurring bacteria helped break down methane in the oil by converting it into carbon dioxide and water. These bacteria prevented large amounts of methane from being released into the atmosphere and contributing to global warming. Bacteria are also useful in bioremediation for sequestering heavy metals at polluted sites.
STEM and Cell Structure and Function
Even though the structures within cells are extremely small, the processes they carry out are highly complex and essential for the survival of an organism. These processes include protein synthesis and replication of genetic material. Molecular biologists are scientists who study these processes to develop ways to treat diseases, protect the environment, improve agricultural crops, and understand the processes underlying evolution.
Molecular biologists study the chemical compounds and processes that make life possible. What sets them apart from other biologists is that they study life at the molecular level. Their studies take them to the very foundation of living cells. Some molecular biologists study very large molecules, notably nucleic acids and proteins, while others may be concerned with a specific type of cell. In addition, molecular biologists may work on a variety of important problems. A molecular biologist might work on discovering the genetic basis of a disease or creating a new vaccine. Another might work to discover the entire genetic code of an organism or on genetically modifying a crop species. Some molecular biologists study evolutionary paths, while others help law enforcement identify a criminal from DNA evidence.
Even though molecular biologists are interested in the tiniest units of life, they do not spend all day looking through a microscope. In addition to doing research, people in this field often work as teachers and scientific advisors. Molecular biologists frequently collaborate with other experts as part of their research.
Teacher Note
Refer to the Examining Cells and Tissues Teacher Guide.
