The Structure of Leaves
Julia Wellons, Sophia Kinnear, Tyler Rathkamp, Andrew Zhang
Structures and Functions
Stoma (Stomata)-these tiny pores are the way by which carbon dioxide enters the leaf, and oxygen exits
Vein- water is absorbed and by the roots and is delivered to the leaves in veins.
Chloroplast- The organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of arguing molecules from carbon dioxide and water.
Thylakoid-a disk shaped membranous sac inside the chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis.
Granum- a stack of Thykaloids
Chlorophyll- a light-absorbing pigment in the chloroplasts that plays a central role in converting solar energy to chemical energy.
Carbon Dioxide- enters through the stomata on the underside of the leaf
Oxygen- Exhaled through the stomata
The shape of a leaf is determined by balancing the need to dissipate heat and the need to have the largest surface area to capture the most sunlight. Leaves at the top of a tree tend to be thinner and smaller to better dissipate heat, and the thinness also allows light to pass completely through the leaf to let leaves below capture sunlight as well. The leaves at the bottom of a tree tend to be larger and thicker to better capture sunlight.
The climate affects leaves as because the shape of leaves depend on the amount of sunlight a leaf gets and the humidity of the air. Needle shaped leaves, like those of the evergreen, have a smaller amount of surface area to prevent water loss in dry winters, as well as a far thicker cuticle.
Campbell, Neil A. Biology: Concepts & Connections. Custom ed. Vol. 6. New York: Pearson Learning Solutions, 2009. Print.