Carbs - Cellulose Flashcards
What is made from cellulose?
The cell wall of plants
What is cellulose am example of?
A structural polysaccharide
What does cellulose do?
What does it make the cell?
It is very strong and stops plant cells bursting when too much water enters by osmosis
It makes the cell turgid
What does the turgidity of cellulose provide?
Enough strength to each cell to support the whole plant
What is cellulose composed of?
It’s structure
It’s composed of many thousands of ß-glucose molecules joined together by 1,4 glycosidic bonds
What must happen to be able to for, the 1,4 glycosidic bonds?
Each ß-glucose molecule must be inverted by 180° from the previous molecule
Why does each ß-glucose molecule need to be inverted?
The inversions keep cellulose from colliding and results in a long, straight chain
What does straight cellulose chains allow?
It allows many chains to run parallel to each other
What does having chains running parallel to each other result in?
What forms between the hydroxyl groups?
What does this result in?
Hydroxyl groups being in close proximity
Hydrogen bonds form between the hydroxyl groups on adjacent chains
Which results I’m cross-linking between cellulose chains
How is cellulose strong?
While each individual hydrogen bond is weak the many thousands of hydrogen bonds collectively make cellulose very strong
How are stronger fibres formed?
The hydrogen bonds that cross-link the cellulose chains allow the chains to form into stronger fibres
Fibres
How is extra strength provided to the plant cell wall?
(4)
- cellulose chains bundle together to form microfibrils
- microfibrils bundle together to form larger fibres called macrofibrils (fibres)
- macrofibrils (fibres) wrap around plant cells in multiple layers at different angles
- the wrapping fo the strong cellulose fibres around the plant cell provides extra strength
Cellulose if the main component of plant walls. What does it make it in the world?
The most abundant organic material
Why is cellulose not an easily digestible food source?
Because it’s very hard to break down by hydrolysis
Why is it hard to break cellulose down by hydrolysis?
Because most animals lack the cellulase enzyme needed to break the 1,4 glycosidic bonds between ß-glucose molecules
What type of animal has a way to break down cellulose?
Herbivores
How do herbivores break down cellulose?
They have a symbiotic bacteria in their guts which produces the cellulase enzyme
How does being able to digest cellulose benefit herbivores?
They can digest a larger portion of their diet and gain more energy
Why is cellulose important to the human diet?
Because it provides the fibre needed to keep the digestive system healthy
