The Theme of Biology in Stoichiometry

Water from a Camel: Storing Water as Tristearin

Who would have thought we could get a lesson in stoichiometry from camels? True story. What's the first thing you think of when you imaging a camel? It's probably not their dashing good looks. Instead we typically recognize camels by their humps (their humps, their lovely camel humps).

Did you ever really think why a camel has humps? There actually is a biological importance to those humps. Camels live in a harsh environment. Think about it. The desert: no food, no water, no shelter. Sometimes camels can go for days without eating or drinking. Can you guess how they survive? Their (lovely camel) humps.

Camels live in a harsh environment.

To combat the lack of resources in the desert camels actually store energy and water in their humps in the form of tristearin. It's that fancy long chain molecule shown below. Oxidation of tristearin produces water and energy. Who knew camels were so smart.

Tristearin Molecule.

Here's the reaction going on inside those humps. We balanced the equation for you.

2 C₅₇H₁₁₀O₆ + 163 O₂ → 114 CO₂ + 110 H₂O

Let's try out a problem based on our humped friend. What mass of water in grams is produced from 2.5 kg of fat (tristearin)?

First off all, let's convert 2.5 kg of fat into moles of fat. Remember the fat is the tristearin:

Now let's convert from moles of fat to moles of water:

Finally, we just need to convert moles of water to grams of water:

We'll never look at a camel the same way again.