CELL WALLBy: Eetu Eklund and Austin Hurdle

Structure

Cell walls consist of 3 types of layers Middle lamella: This is the first layer formed during

cell division. It makes up the outer wall of the cell and is shared by adjacent cells. It is composed of pectic compounds and protein.

Primary wall: This is formed after the middle lamella and consists of a rigid skeleton of cellulose microfibrils embedded in a gel-like matrix composed of pectic compounds, hemicellulose, and glycoproteins.

Secondary wall: formed after cell enlargement is completed. The secondary wall is extremely rigid and provides compression strength. It is made of cellulose, hemicellulose and lignin. The secondary wall is often layered.

Location

The cell wall is at the outer edges of a plant cell.

The cell wall protects the cell form its outside surroundings.

The cell wall maintains the cell’s shape.

It controls the cell’s rate and direction in which it grows. Provide tensile strength and limited plasticity which are important for:

keeping cells from rupturing from turgor pressure turgor pressure provides support for non-woody tissues

Thick walled cells provide mechanical support Tubes for long-distance transport Cutinized walls prevent water loss Provide mechanical protection from insects & pathogens Physiological & biochemical activities in the wall contribute to cell-cell

communication

Function

Cell Walls are only existent in a plant cell

Works cited http://www.google.com/imgres?

q=Plant+cell+microscope+image&um=1&hl=en&safe=active&rls=com.microsoft:en-us&tbm=isch&tbnid=mhbZdnzoYb1fNM:&imgrefurl=http://www.williamsclass.com/SeventhScienceWork/CellTheoryParts.htm&docid=ro9oSBG1RdiTqM&imgurl=http://www.williamsclass.com/SeventhScienceWork/ImagesCells/ElodeCells.jpg&w=523&h=478&ei=BAADT5_DD-Hg0QGvy7xN&zoom=1&iact=hc&vpx=381&vpy=265&dur=359&hovh=215&hovw=235&tx=188&ty=130&sig=104202251081147810074&page=1&tbnh=123&tbnw=135&start=0&ndsp=18&ved=1t:429,r:7,s:0&biw=1280&bih=599

http://sites.bio.indiana.edu/~hangarterlab/courses/b373/lecturenotes/cellwall/cellwall.html

http://www.google.com/imgres?q=Plant+cell+microscope+image&um=1&hl=en&safe=active&rls=com.microsoft:en-us&tbm=isch&tbnid=ZiozKbYVooJAlM:&imgrefurl=http://photo.net/digital-camera-forum/00Lqz8&docid=iq7F-GsxvqGbxM&imgurl=http://static.photo.net/attachments/bboard/00L/00LrAE-37443684.jpg&w=1024&h=768&ei=BAADT5_DD-Hg0QGvy7xN&zoom=1&iact=hc&vpx=507&vpy=183&dur=47&hovh=194&hovw=259&tx=161&ty=100&sig=104202251081147810074&page=10&tbnh=112&tbnw=149&start=188&ndsp=23&ved=1t:429,r:11,s:188&biw=1280&bih=599