Why do grains have so many more carbs than other plant foods, like nuts or lettuce?

Question

Googling isn’t helping, because the results are all from health and diet pages. I’m trying to find a science answer.

[Request] Please try and actually explain this to a 5-10yo. I have a kid in that age range who’s the one actually asking the question. I can do my best to bring an “I graduated high school” answer down to his level, but I might struggle to bring an “I’ve completed some college and have a basic background in biochemistry” answer to his level. Thanks!

In: 62

Answer 1

I won’t go into the evolutionary *why* (for many crops we grow nowadays, selective breeding and/or GM techniques have made them do things that really don’t make a lot of sense for the plants themselves), but the biochemical *how* boils down to “while many plants have the set of tools necessary to take in nutrients from soil + energy from sunlight to make all sorts of molecules they need, grain-like plants also have (and use) particular tools to make lots of carbs.”

Making large carbohydrates out of little bits of carbon, hydrogen and oxygen is nothing strictly special when you have the enzymes to do it. Humans synthesize all sorts of things from smaller building blocks, too. You can eat almost any blend of protein in your everyday diet and turn it into big muscle fibers, finger nails, you name it.

Answer 2

I won’t go into the evolutionary *why* (for many crops we grow nowadays, selective breeding and/or GM techniques have made them do things that really don’t make a lot of sense for the plants themselves), but the biochemical *how* boils down to “while many plants have the set of tools necessary to take in nutrients from soil + energy from sunlight to make all sorts of molecules they need, grain-like plants also have (and use) particular tools to make lots of carbs.”

Making large carbohydrates out of little bits of carbon, hydrogen and oxygen is nothing strictly special when you have the enzymes to do it. Humans synthesize all sorts of things from smaller building blocks, too. You can eat almost any blend of protein in your everyday diet and turn it into big muscle fibers, finger nails, you name it.