Where does the energy in food come from?
a. proteins, carbohydrates, or fats
b. atp
c. food, by itself, doesn't contain energy, but the digestive system creates it.
d. the chemical bonds holding the food molecules together
e. combining water with any sort of food creates energy.

A. Proteins, Carbohydrates, or fats

Explanation:

There are essential nutrients for life in which we can include carbohydrates, fats, proteins, minerals, vitamins, fiber, and water.  The main nutrients we use for energy are carbohydrates, fats, and proteins. This is because they contain calories in them and the calories are what our body needs to create energy.

Our bodies, like a car, need fuel to function. The fuel we need comes from food. The food has energy stored in it so whenever we eat food, that stored energy is transferred to us. This food act as fuel for the cells in our body so they can carry all the metabolic processes and give us the energy to move, run, think, talk, digest and all of the biological processes we need to survive.

answer; both surfaces of the membrane are nonpermeable

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?