Photosynthesis and Thermodynamics

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Basic Postulates:
1) Plant function is understood on the basis of chemistry and physics.
2) Four of the five kingdoms are studied by plant physiologists; mostly gymnosperms and angiosperms (plantae).
3) The cell is the fundamental unit of life (cell theory):
a. All living things are composed from/of cells.
b. Life doesn't exist in units smaller than cells.
c. Biogenesis - Cells arise from pre-existing cells.
4) Eukaryotic cells contain membrane-bound organelles.
5) Cells are characterized by macromolecules (starch, cellulose).
6) Cells have proteins and nucleic acids (DNA, RNA).
7) In multicellular organisms, cells are organized into tissues and organs; different cells may have different structures and functions.
8) Living organisms are self-generating structures.
9) Organisms grow and develop within environments and interact.
10) Structure and function are inter-dependent.

Source: http://www.uic.edu/classes/bios/bios100/labs/plantanatomy.htm

Plant Cells
1) Parenchyma - thin cell wall and sometimes isodiametric, living. Found in pith, cortex, mesophyll, and other tissues.
2) Cell Wall - many protistans and most fungal and plant cells are surrounded by a cell wall
? Primary Wall (1° wall) - usually thin (1-3 nm), 9-25% cellulose. Microfibrils are constructed and long unbranched cellulose molecules bound together in cylindrical fibers. 1° wall begins to form between cells that are completing cell division; a cell plate forms where a new call wall will divide the 2 daughter cells. Cellulose microfibrils are embedded in a matrix of other materials, principle among them the hemicelluloses, which form a branching, molecular network filled with water. A typical primary wall may contain 25-50% hemicelluloses. Other materials of the matrix are pectic substances (calcium pectate) - a cementing substance - which makes up 10-35% of 1° wall. 1° wall also contains about 10% protein, which plays an important role in cell growth.

? Secondary Cell Wall (2° wall or SCW) - much thicker than 1° wall, especially those in xylem tissues that, when mature, provide support for plant or will conduct fluid under tension; the protoplast secretes a secondary wall after the cell has ...