What does baking soda, used for making cakes rise, have to do with human blood and the acidification of our increasingly polluted oceans? Quite a lot, according to researchers at Ben-Gurion University of the Negev in Beersheba who have laid the groundwork for a new understanding of how our blood functions.
Their discovery is so important that physiology textbooks around the world will have to be modified according to the new findings. Prof. Ehud Pines of the of the chemistry department and his team have experimentally demonstrated that carbonic acid plays a much greater role in how our blood manages its acidity than previously imagined.
His results were published recently in Proceedings of the [US] National Academy of Sciences America (PNAS). The prestigious paper follows a substantial grant from the US National Institutes of Health (NIH) that he received with Prof. James T. Hynes of the University of Colorado at Boulder to explore the role of carbonic acid in the blood. Pines’ team also included doctoral student Daniel Aminov and Dr. Dina Pines.
Carbonic acid is either created from CO2 and water or by mixing an acid with bicarbonate, which is just the familiar baking soda. When mixed with even a weak acid such as lemon juice, it produces carbonic acid which then breaks down into CO2 and water. CO2 is a gas, which explains its for making cake dough rise.
Carbonic acid is unstable, and when it breaks down, it produces carbon dioxide and water. In our bodies, it turns out there is a lot of “baking soda” in our blood, which helps regulate the amount of carbon dioxide our bodies are producing and helps keep the acidity of our blood constant. However, carbonic acid was considered too unstable to be significantly reactive as an acid before breaking down into carbon dioxide and water.
But now, Pines and his team have shown that carbonic acid does react as an acid; it lasts just milliseconds, but in that span, it manages to “protonate” biological bases and to supply biological reaction centers with protons which are necessary to sustain life-sustaining processes. Protonation means adding positive charges to a molecule, which changes its chemical properties and reactivity. They demonstrated that it must play a much more significant role than aqueous protons, which, until now, were considered the major players in this very common basic chemical reaction in our blood.
This discovery of one of the basic properties of carbonic acid in our blood could force scientists to reconsider much of what we thought we knew about how our blood keeps us alive with a whole raft of implications. How do drugs react with the carbonic acid in our blood? How does physical trauma affect carbonic acid protonation? These are the questions with which scientists, physicians and drug makers must now contend.
Their discovery of the protonation capabilities of carbonic acid also has major implications in another environment entirely where a similar situation exists – the acidification of the oceans. A new UN report released recently warned that rising acidification in the oceans represents a major threat to their food-producing capabilities and the well-being of most organisms that live there.
In particular, it was suggested that the rising acidity of the oceans dissolves the skeleton of corals, which make them prone to mechanical destruction by strong waves and storms. As a result, corals are being destroyed all over the world – as is painfully evident in the big coral reefs off the shores of Australia. Including carbonic acid in the calculation of the marine biology balance increases the severity of the UN assessment and the projected ill-effects of ocean acidification due to the rising CO2 concentration in Earth’s atmosphere. Future additional infusions of carbonic acid because of rising amounts of CO2 in the atmosphere caused by human activities could mitigate that acidification.
