Properties of plants T4 Flashcards
Describe the structure of a cellulose cell wall.
3
- Polymer/chain of B-glucose.
- Cellulose molecules held together by hydrogen bonds as microfibrils.
- Microfibrils arranged in parallel/criss cross.
- Matrix/hemicelluloses/pectin.
Is cellulose branched?
No.
The monomers are held together by glycosidic bonds in an unbranched chain.
What is meant by the term tissue?
One or a few types of cells working together for the same function.
Describe the function of the xylem.
2
- Transport of water.
- Transport of minerals.
- Structural support.
Describe the structure of a cellulose microfibril.
4
- Cellulose contains beta-glucose.
- Glucose molecules joined by a condensation reaction.
- Forming glycosidic bonds.
- Only 1,4 glycosidic bonds.
- Unbranched straight chains.
- Microfibril composed of many cellulose molecules.
- Cellulose chains held together by hydrogen bonds.
The concentration of magnesium ions in the soil was found to be very low.
Explain the effects of a shortage of magnesium ions on a plant.
(3)
- Shortage of magnesium ions limits production of chlorophyll.
- Lack of glucose/carbohydrate/cellulose due to less photosynthesis.
- Therefore plant leaves may be yellow/plants may be small.
Why does the food store in seeds contain starch rather than cellulose?
(1)
Starch is branched so supplies energy quicker then cellulose.
Explain why starch must be broken down before it can be used by the cells of the growing plant.
(2)
- To produce glucose/maltose.
- Which is soluble/so can enter cells easily/transported/used in respiration.
What is the role of sclerenchyma fibres?
Provide support.
Purpose of phloem?
Transporting organic nutrients around the plant body.
Such as sugar and amino acids.
How do you cross the plant cell wall?
Through the plasmodesmata.
Through pits in the cell wall.
How is the xylem strong?
Is lignified.
Solutes and water can’t be absorbed.
