Cell WallThese are found in plant cells onlyCell walls provide mechanical support

and protection

Because the wall prevents the cell from bursting this allows turgor pressure to give the plant support

The wall is made from cellulose and other polysaccharides

Fungi and Prokaryotes have cell walls made of other substances

The cell wall is made in Golgi

apparatus

Golgi vesicles move to the cell plate (at the equator of a dividing cell) at the end of nuclear division Golgi vesicles

containing Calcium pectate

Forming cell plate with middle lamella being formed

Note the vesicle membrane surrounds the new wall

The vesicles fuse to form the middle

lamellaThis contains Calcium Pectate which

holds the neighbouring cell walls together

The membranes from the vesicles fuse to form the cell surface membrane

• The primary cell wall is made next• This is made of cellulose molecules

that are bundled together to form microfibrils

The bundles are held by Hydrogen-

bonds These are in turn bundles to form

cellulose fibresHemicellulose and pectins hold fibres

togetherCellulose has a high tensile strength

The primary cell wall laid down in different

directionsThere are gaps in the wall called

plasmodesmata through which cytoplasmic connections are made between cells

The Secondary wall is only laid down once the cell has stopped growing

The cellulose fibres are laid in different directions which increases the strength

They may have lignin or suberin addedThe cellulose cell wall is freely permeable.Water and ions move through the spaces

between the cellulose fibres. This is called the apoplast