The Parts of the Leaf Introduction to Photosynthesis

Up Close with a Leaf… Important Parts: Epidermis/Cuticle Stoma and Guard Cells Vascular Bundle Spongy Mesophyll

Epidermis/Cuticle The epidermis is an outer layer of cells that protects the plant. It is coated with a cuticle, a waxy covering that surrounds a plant. It helps keep water in the plant – thus preventing it from wilting! Cuticle Epidermis

Stoma and Guard Cells Stoma are openings on the underside of a leaf that allow gas to pass in and out of the leaf. To prevent water loss stoma are surrounded by guard cells that open and close the stoma. On the left is a picture of an open stoma while the right shows a closed stoma.

Vascular Bundles: Composed of two parts Xylem cells form tubes that bring water from the roots to the rest of the plant. Phloem cells form tubes that bring food from the leaves to the rest of the plant. Vascular Bundle

Mesophyll Cells Mesophyll cells are cells inside of the leaf that contain numerous chloroplasts

Chloroplasts Chloroplasts are the organelle in plant cells responsible for converting light energy into chemical energy.

Chloroplasts: Three important parts The thylakoid converts light energy to chemical energy. This is where CHLOROPHYLL is located! Thylakoids are stacked like pancakes in stacks known collectively as grana (granum). Area of the chloroplast outside of the thylakoid is called the stroma. (Notice the ‘r’. Do not mix this up with the stoma.)