What are leaves and what do they do?

Photosynthesis

•The process in which plants turn water and carbon dioxide into sugar is called photosynthesis.

•Plants use sunlight to turn water and carbon dioxide into glucose (sugar).

Photosynthesis (continued)

•Cells in the plants leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components.

•Carbon dioxide then enters the leaf and combines with the stored energy in the chloroplasts through a chemical reaction to produce a simple sugar.

•The sugar is then transported from the leaf to the rest of the plant or tree to be used for energy.

•Oxygen is released from the leaf through the process of Photosynthesis.

Why are leaves green?

•There are different color pigments in leaves. They are Chlorophyll, Xanthophyl, Carotene, and Anthocyanins.

•Chlorophyll is the most abundant pigment in a leaf and gives it a green color. The other pigments cannot be seen.

Autumn Leaves

•In Autumn, the days grow shorter and the temperature drops.

•Leaves respond to the decreasing amount of sunlight by producing less and less chlorophyll.

•When chlorophyll production stops, the other pigments in the leaves begin to show through.

Factors that influence the amount of fall color the leaves will wear each year include:

•Rain•Amount of sugar in the leaves•Wind•Temperatures

Cool, bright sunny days and chilly nights create the brightest colors. The colors also depend on the makeup of the trees and other plants.

Leaf Colors

•YELLOW- This is caused by the pigment Xanthophyl.Some trees that turn this leaf color are: Ash, Birch, Beech, Butternut, Elm, Hickory,Poplar, and Black Maple.

•RED- This is caused by the pigment Anthocyanin.Some trees that turn this leaf color are: Northern Red Oak, Red Maple, and Sumac.

•ORANGE- This is caused by the pigment Carotene.Some trees that turn this leaf color are: Sugar Maple and some Oaks.

Winter is Coming!Leaves can freeze in the winter. They must be shed so that the rest of the plant can survive throughout the winter.

•A layer of cells, called the separation layer, forms at the base of the leaf stem.

•When this layer is complete, the leaf is separated from the tissue that connected it to the branch, and it falls.

Oak leaves are an exception. They never fully detach and remain on the tree throughout the winter.

Evergreen trees do not lose their leaves because their leaves contain substances that resist freezing.

Leaves Lesson-Fifth GradeCreated by

Janice Sullivan

EDU 6621Integrating Technology Into The Curriculum

Professor Morote

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