Dissect the anatomy of icosahedral, rod-shaped, and bacteriophage virus structures in electron micrographs
Animation and microphotography illustrating the structural diversity of viruses.
Encyclopædia Britannica, Inc.
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Encyclopædia Britannica, Inc.Erik Gregersen, astronomy and space exploration editor, discusses space junk—material left floating in space after past space missions—and how the problem is getting worse every day.
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Encyclopædia Britannica, IncSee the world through a deer's eyes. This visual comparison highlights the key differences between human trichromatic vision and deer dichromatic vision, showing how deer perceive shades of blue and yellow while red and orange hues appear muted.Media Editor: Meg Matthias
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Encyclopædia Britannica, Inc.Learn about phytoplankton, plantlike types of microscopic algae that live suspended in bodies of water such as oceans. The term phytoplankton comes from the Greek words phyton (“plant”) and planktos (“wandering”). Examples of planktonic algae include diatoms and dinoflagellates.
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Encyclopædia Britannica, Inc.The cycle of infection results in the death of the host cell and the release of many virus particles, called virions.
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Encyclopædia Britannica, Inc.Bacterial DNA can pass from one cell to another through the processes of conjugation and transduction.
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© Massachusetts Institute of Technology (A Britannica Publishing Partner)Learn how a benign bacterial virus can be used to improve the performance of lithium-oxygen storage batteries.
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Encyclopædia Britannica, Inc.Animation of an icosahedral (20-sided) virus.
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Transcript
NARRATOR: Different viruses have different shapes. Some look roughly spherical under the electron microscope, but their exact geometry is an icosahedron, a figure with 20 triangular faces.
There are also rod-shaped viruses. The rod has two layers wrapped together. At the center is a strand of nucleic acid; the outside shell is protein spirally wound in a long helix.
Probably the most dramatically shaped viruses are called bacteriophages, or phages. The head of the phage is a hollow protein capsule that contains nucleic acid. Beneath that is a shaft called a sheath. Attached to the sheath are leglike tail fibers.
There are also rod-shaped viruses. The rod has two layers wrapped together. At the center is a strand of nucleic acid; the outside shell is protein spirally wound in a long helix.
Probably the most dramatically shaped viruses are called bacteriophages, or phages. The head of the phage is a hollow protein capsule that contains nucleic acid. Beneath that is a shaft called a sheath. Attached to the sheath are leglike tail fibers.
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