Svedberg converter
Convert sedimentation coefficients between svedbergs and seconds, the unit ribosomes are named after.
That's about the same as a bacterial ribosome. At 100,000 g it would settle about 24.71 mm an hour.
What it means
How fast does it settle?
Svedberg values depend on shape as well as mass, which is why they do not add: the 30S and 50S subunits make a 70S ribosome.
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Three things worth knowing
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30S + 50S = 70S
Not 80. Joining the subunits makes a more compact particle, which settles less than the sum of its parts would suggest.
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Svedberg built the machine
Theodor Svedberg invented the ultracentrifuge in the 1920s and won a Nobel Prize for showing that proteins are molecules of definite size, not random aggregates.
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It is not a molecular weight
A long thin molecule settles more slowly than a compact one of the same mass, so S values cannot be converted into daltons without knowing the shape.
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Background
About svedbergs
A svedberg is 10⁻¹³ seconds, and it measures how fast a particle settles in a centrifuge per unit of applied acceleration. Bigger and denser particles have higher values.
It is also why ribosome parts have such strange names: the bacterial ribosome is 70S, made from a 30S and a 50S subunit. They do not add up, because shape matters as much as mass.