Carrots

Someone once told me that baby carrots are really just normal carrots chopped into smaller pieces. I thought that was a lie until now. I was eating some baby carrots when I came across this one:

Apparently, this chunk of carrot escaped the machine that forms baby carrots from larger ones. Now I have proof that baby carrots don't exist naturally. Anyways, this reminds me of something interesting:

Why are carrots orange?

I'm sure everyone has asked this question at some point, but the answer is always indirect. You'll probably hear something like, "They're orange because they have a lot of beta-carotene in them." Well, if anyone has ever wondered why beta-carotene is orange, I can answer that. Here's the chemical structure of beta-carotene: 

beta-Carotene

One of the most obvious characteristics of beta-carotene is its conjugation. Generally, this means that the molecule has alternating single and double bonds. Furthermore, it means that the p-orbitals are overlapping, and electron delocalization is occurring. In other words, the electrons in beta-carotene (and other conjugated systems) are special. These special, delocalized electrons are capable of absorbing photons with wavelengths that correspond to visible light. The reason why carrots are orange is because beta-carotene is capable of absorbing photons with a certain wavelength; this causes humans to perceive them as orange. 

FYI: You might have noticed the structure of beta-carotene closely resembles that of vitamin A. This is because beta-carotene can be a metabolic precursor to vitamin A (aka retinol).