Inorganic ions like nitrate (NO3–), calcium (Ca2+), hydrogen carbonate (HCO–3), potassium (K+), iron (Fe), magnesium (Mg2+) and phosphate (PO43-) are key components of molecules in living things. Here are a few examples of where they can be found and what their role is within plants.
Nitrate ions are extracted by plants from the soil, and their nitrogen atoms used for other things. There are of course the nitrogenous bases in DNA (adenine, guanine, cytosine and thymine) as well as amino acids – hence amino acids. Get it get it.
This of course applies to all life since all life does have DNA (or RNA) and amino acids.
Calcium ions have a key role in calcium pectate which I have just googled. I’m afraid what I found is far too hilarious to ignore:
“Calcium pectate, a pectin fiber that adds crispness to fruits and vegetables, also has potent cholesterol-lowering properties.”
Crispness. There you go. Crunchy kale. Crisp apples. Tooth-chipping swede. Crunch.
Anyway, back to the calcium pectate. The calcium ions bind to pectin (a carbohydrate) in plant cell walls creating a pectate salt, and contribute to its strength and stability. It’s present in all fruit and vegetables.
Hydrogen carbonate acts as an intermediary product between CO2 released from cellular respiration and water, and its reverse reaction releases CO2 back in the lungs for expiration.
Potassium, alongside sodium, are key ions in metabolism as they maintain concentration gradients in nerve signals, glucose absorption and other cellular functions.
These concentration gradients are maintained via a protein pump found on the cell membrane that is able to recognise these ions and selectively pump them to the opposite side of the cell membrane, in order to keep the equilibrium of ions either side.
Haemoglobin which is a good friend circling oxygen round the bod for max performance and non-dead status has iron ions at its core to actually bind the oxygen. Apparently we have an inch of an iron nail’s worth of iron in our body? BOO YAH IT’S ‘APPENIN.
Magnesium ions are central to photosynthesis in plants because they are a constituent of chlorophyll. Chlorophyll is the pigment that enables the use of light in extracting chemical energy from water (water and carbon dioxide are used in photosynthesis to make glucose).
Spot magnesium right at the heart of it, and notice a familiar neighbour?
Righty, onto our last superstar inorganic ion of the day: phosphate. Phosphate is a key part of ATP and ADP (adenosine triphosphate and its dephosphorylated sibling, adenosine diphosphate).
Now you haven’t yet been introduced to this usual suspect – rude. ATP has energy in its third phosphate group, which is always broken to release it. This happens all the time and makes ATP the energy currency of living systems. During cellular respiration, ADP receives the energy back to make more ATP and the cycle goes on.