Revision notes topic questions past papers

must be rotated to 180° to each other

Due to the inversion of the β-glucose molecules many hydrogen bonds form between the

long chains giving cellulose it’s strength

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CIE AS Biology (9700) 2019-2021 Revision Notes

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2. Biological Molecules

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CIE AS Biology (9700) 2019-2021 Resources

REVISION NOTES 

 

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Page 30

Cellulose is used as a structural component due to the strength it has from the many

hydrogen bonds that form between the long chains of β-glucose molecules

Cellulose – function

Cellulose is the main structural component of cell walls due to its strength which is a

result of the many hydrogen bonds found between the parallel chains of microfibrils

The high tensile strength of cellulose allows it to be stretched without breaking which makes

it possible for cell walls to withstand turgor pressure

The cellulose fibres and other molecules (eg. lignin) found in the cell wall form a matrix which

increases the strength of the cell walls

The strengthened cell walls provides support to the plant

Cellulose fibres are freely permeable which allows water and solutes to leave or reach the

cell surface membrane

As few organisms have the enzyme (cellulase) to hydrolyse cellulose it is a source of fibre

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