D16 plant cell wall

Question 1

What is the structure of a plant cell wall?

Answer 1

A plant cell wall is mostly composed of cellulose

The cellulose molecules are polymers of beta glucose (polysacheride), which form 1,4 glycosidic bonds.

They form microfibrils which are then held together by many hydrogen bonds which provides strength to the cell wall.

(microfibrils which are aggregated into fibres embedded in a polysaccharide)

Question 2

What are the 3 functions of a plant cell wall (introduction only)

Answer 2

Transport

Mechanical strength

Communication between cells

Question 3

What are the 3 functions of a plant cell wall

A* answer”Transport”

Answer 3

There are gaps between the cellulose microfibres which makes the plant cell wall fully permeable to water, dissolved molecules and ions

The space outside the cell where solution moves is called the apoplast

The apoplast pathway is the main way water enters the root of a plant

Question 4

What are the 3 functions of a plant cell wall

A* answer” Mechanical Strength”

Answer 4

The structure of cellulose microfibrils and their laminated arrangement make the cell wall very strong.

When the vacuole is full of solution, the cell contents push against the cell wall, which resists expansion and the cell become turgid supporting the plant.

Question 5

What are the 3 functions of a plant cell wall

A* answer”Communication between cells”

Answer 5

1. Cell walls have pores called pits through which strands of cytoplasm called plasmodesmata (SIngular - Plasmodesma) pass
2. Each plant cell has approximately 100,000 plasmodesmata connecting them to other cells
3. The plasmodesma are found where there is no cellulose thickening between two cells
4. The strand of cytoplasm runs from one cell to the next
5. The network of cytoplasm in connected cels is called the SYMPLAST.
6. The symplast pathway is important in later transport through a plant.