Reef Chemistry Question of the Day #93 Element Ratios

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #93

When organisms grow, they use specific amounts of the various building blocks of matter. Since most of the basic biochemicals of life are similar in different organisms (proteins, fats, DNA, etc.), the relative amount of certain atoms incorporated are similar. In the case of phytoplankton, for example, this is called the Redfield ratio of certain nutrients taken up from the water, with the C, N and P shown below representing carbon, nitrogen, and phosphorus atoms, the relative amounts taken up by typical phytoplankton or algae are best represented by which of the following?


A. Carbon > nitrogen > phosphorus
B. Carbon > phosphorus > nitrogen
C. Nitrogen > carbon > phosphorus
D. Nitrogen > phosphorus > carbon

Good luck!



































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[beaslbob]

A.

sounds as good as any

 

[tonizzy22]

Answer is A C106:N161

 

[tonizzy22]

LOL emote was not intended.

 

[beaslbob]

every get the feeling Randy has some point on the redfield ratio?

 

[Cory]

I'm going to say A but thought C, but after I seen the ratio posted up there I knew it was A.

So organisms take up elements. What about my sea anemone? If the sodium level was lower but sulphur was higher would that cause a problem to the animals?

 

[Nano sapiens]

Everyone got this one

A:

C:N = 106:16:1

 

[Randy Holmes-Farley]

And the answer is...A. Carbon > nitrogen > phosphorus yes, everyone got it!

Most tissues have roughly similar ratios unless they incorporate things like energy storage molecules (fat, poly(hydroxybutyric acid), etc.) or structural elements (wood, calcium carbonate, etc.) or some other special purpose chemicals stored up (venoms, etc.).

Cory, a sea anemone will actively exclude both chloride and sulfate. Meaning it has less inside than seawater contains,. Same for sodium. But I do not know about how problematic it is for a creature to be in an off ratio of chloride to sulfate, for example.