cell wall

Hannah Wislang
Flashcards by Hannah Wislang, updated more than 1 year ago
Hannah Wislang
Created by Hannah Wislang over 4 years ago


100 cells biology Flashcards on cell wall, created by Hannah Wislang on 03/30/2016.

Resource summary

Question Answer
Primary cell wall Produced by young cells and is thin and fexiable to allow the cell to grow
Cell wall composition made of hemicellulose and pectin
Hemicellulose Is a heterogeneous group of polysaccharides, long chains of one sugar and short side chains of another sugar form a rigid structure
Pectin Is a branched negatively charged polysaccharide they bind water and have a gel like property
Secondary cell wall Is produced after the cell has stopped growing, not all cells have a secondary cell wall. they are thicker and stronger than the primary cell wall so provide more structural support.
Secondary cell wall is made up of Multiple layers, the microfibrils in each layer have different orientations, which strengthens the cell wall
Chemical characteristics of the secondary cell wall Has more cellulose and less pectin and 15-35% lignin
Lignin is the second most Abundent organic marcomolecule and is a complex phenolic poylmer
Lignin function Provides strength and rigidity and hydrophobicity to the cell wall
Pit field An area with multiple plasmademata
Plasmademata Are Cytoplasmic channels that connect the cytoplasm of adjacent cells, they make the cytoplasm continuous
Plamademata function Allow the exchange of small molecules are to small to let organelles through
Extensions are associated with... Extensibility
When extentions are arranged in an unorganised way The cell is able to extent and expand
When extensions are arranged in a cross linked way The cell wall becomes dehydrated and strengthens which means that the cell cannot get any bigger
Synthesis of the primary wall Cellulose mircofibrials are made in the plasma membrane and secreted out into the outside space outside the cell.
Pectin and hemicellulose polysaccharides are made in the Golgi apparatus, They are packaged up into secretory vesicles these vesicles then bind to the plasma membrane and release the contents out of the cell
Extensions produced in the Rough endoplasmic reticulum are transferred to the cell wall via the golgi
In the cytoplasm of the cell sucrose is present The glucose part of the sucrose molecule is broken off, the glucose molecules are then binded to each other by the enzyme cellulose synthase. This occurs in the plasma membrane.
These cellulose chains are then Released out of the plasma membrane
The plant controls were cellulose Is laid down, cellulose synthase covers the width of the plasma membrane so it is able to interact with the microtubules. Cellulose synthase can travel along the microtubules releasing cellulose. This allows for tight control on where cellulose is put, which is important for cell shape
The orientation of the cellulose mircofibrils Influences the cell morphology. Cellulose being laied out along the x axis will prevent the cell from getting wider
Cell wall function Acts as a protective barrier, protects against fungi, when a plant is affected by a fungi the cells can produce a fungicide containing inclusion bodies, neighbouring cells can also secrete the fungicide into the cell wall to protect themselves
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