Structure and function of the sheet
Cuticle / cuticle (lat. cutis = skin) covers the outer walls of the epidermis; consists of a water-impermeable, hydrophobic wax layer, which prevents the evaporation of water.
epidermis (Greek epi = about, derma: skin) is located between the cuticle and palisade tissue; transparent, there are no chloroplasts in the epidermis, so that light comes through to the palisade tissues; The cell walls of the epidermis give the leaf stability and protect against external influences
palisade tissue: located between epidermis and sponge tissue; very rich in chloroplasts responsible for photosynthesis
spongy tissue: between palisade tissue and cuticle; only a few chloroplasts compared to the palisade tissue; Main function: control of gas exchange -> CO2 diffuses into the leaf, O2 and H2O steam out
Guard cells / stomata: are located on the underside of leaves in the epidermis. If there is little water in the cell, the guard cells are closed. With increasing water content, the guard cells open and release water vapor; For this CO flows2 into the cell interior
vascular bundles: surrounds the xylem (ensures transport of water) and the phloem (ensures the transport of loosened nutrients) through the plant; In addition, the vascular bundle has a supporting function