I don't know if they protect the leaf but there are stomata on the bottom of a leaf. Hope this helps! Sorry for being unreliable...
Definetly cellulose
The Culticle
The cuticle - a waxy layer that protects a leaf's moisture.
The answer is no, because, on the top of a leaf there is the, cuticle, then the upper epidermis cells underneath, which you can see these, because you can see a sort of jigzaw pattern on the top of the leaf. but on the bottom of a leaf there are tiny, guard cells, a guard cell is a cell that lets in carbon dioxide to the leaf, but only on the bottom of the leaf. if you have ever wondered why a leaf is greener on the top, than the bottom of a leaf, is because, sunlight can easily reach the top of a leaf, this is called photosynthesis, but on the bottom of a leaf, it only gets sunlight from refections from the ground, because the bottom of the leaf does not have any visible contact with the sun.
a small leaf like thing called a sepal
cuticle layer
There is more chlorophyll in the top of the leaf than there is on the bottom
A microscopic biologic organism within an individual leaf of a branch of a tree or plant.
The cuticle in a leaf is the waxy covering on top and bottom of the leaf. It is used to conserve water.
the bottom will have more chlorophyll
It's called the "Shade Leaf"
A leaf has a flat, thin structure with an outer epidermis layer that protects the leaf. Inside the leaf, there are layers of cells known as mesophyll, which contain chloroplasts for photosynthesis. The veins of the leaf transport water and nutrients throughout the leaf.