Human Respiration is Carbon Neutral

The very first time you learned about carbon dioxide was probably in grade school: We breathe in oxygen and breathe out carbon dioxide. Any eight-year-old can rattle off this fact. More specifically, the mitochondria within our cells perform cellular respiration: they burn carbohydrates (in the example shown below, glucose) in the oxygen that we breathe in to yield carbon dioxide and water, which we exhale as waste products, as well as energy, which is required to maintain...

 Eating Fish During Pregnancy

I dive deep into the research, its strong currents pushing me first one way—fish is good!—and then the other—mercury is bad!—and finally surface with a seemingly obvious conclusion: eat fish, lots of it, just not the mercury-laden kind. This is harder than it sounds. Fish, to me, has meant a pink slab of tuna steak or a creamy slice of swordfish (or that coveted tuna-salad sandwich). Now I set about getting acquainted with the ocean’s other inhabitants: small fish at the bottom of ...

 Carbon Dating

Of all the elements, carbon is the one that seems most indispensable to life - the one without which life on any planet is hardest to envisage. This is because of carbon's remarkable capacity for forming chains and rings and other complex molecular architectures. It enters the food web via photosynthesis, which is the process whereby green plants take in carbon dioxide molecules from the atmosphere and use energy from sunlight to combine the carbon atoms with water to make sugars. All the car...

 Carbon Dating

Of all the elements, carbon is the one that seems most indispensable to life - the one without which life on any planet is hardest to envisage. This is because of carbon's remarkable capacity for forming chains and rings and other complex molecular architectures. It enters the food web via photosynthesis, which is the process whereby green plants take in carbon dioxide molecules from the atmosphere and use energy from sunlight to combine the carbon atoms with water to make sugars. All the car...