Introduction

Bacteriophages are viruses that infect bacteria. Historically, interest in bacteriophages was first generated by the possibility of using bacteriophages as biological antibiotics. This interest is periodically revived when difficulties are encountered with the use of chemical antibiotics. Interest in bacteriophages was also generated by both the short life cycle and the simple (short) genome of bacteriophages. These characteristics were useful in developing the science of molecular genetics. Bacteriophages were a favourite for asking questions about transfer of biological information via DNA replication, transcription (copying of RNA from DNA) and translation (using the information in RNA to assemble proteins). Today, bacteriophages are used to carry small pieces of the DNA of higher organisms. The purpose is to determine the nucleotide sequence of the pieces and, ultimately, the nucleotide sequence of the whole genome of higher organisms. Basic science uses bacterio-phages as models for understanding how separate molecules assemble to form a complex structure. The questions asked in these studies are fundamental: How do biological motors work? How is specificity maintained in intermolecular binding? How is accuracy assured during assembly? To what extent is biological form determined by either pathway of assembly or energetics of the final structure? Are errors corrected during assembly of biological macro-molecules? Are separate biochemical processes integrated in the context of the interior of a cell? Pursuit of the answers to all these questions requires purification of bacteriophage particles.

Purification of both bacteriophages and bacterio-phage-like particles is also needed for other types of study. Bacteriophage-like particles are present in both lakes and oceans. Some are true bacteriophages. Others are viruses that infect algae, rather than bacteria. Environmental biologists detect and sometimes purify these particles without knowing what they are. Purification helps establish what they are, both biologically and chemically. Finally, bacteriophages are model viruses. Study of the evolution of bacterio-phages helps in the understanding of the evolution of other viruses, including pathogenic viruses. A major advantage of studying bacteriophages is their comparatively short life cycle. For example, bacterio-phage T7 has a 13 min life cycle at 37°C and a 25 min life cycle at 30°C. The host cell is Escherichia coli. Most other bacteriophages that infect E. coli have life cycles less than 60 min at 37°C. Thus, studies of evolution are achieved more quickly than they are with any other organism. Also, the short life cycle of bacterioph-ages reduces the time needed to grow them.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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