Carbohydrates: Chitin | A-level Biology | OCR, AQA, Edexcel
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Carbohydrates: Chitin in a Snap!
Carbohydrates: Chitin in a Snap! Unlock the full A-level Biology course at http://bit.ly/2tjNT60 created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University.
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The key points covered in this video include:
1. Structural Polysaccharides - Chitin
2. Structure of Chitin
Structural Polysaccharides - Chitin
As well as cellulose in plants, structural polysaccharides can be found in other organisms, such as fungi and insects. In fungi, a polysaccharide called chitin is used to strengthen the cell wall. In insects, chitin is also used to give strength to their exoskeleton. Chitin is also waterproof which helps insects prevent water loss from their body.
Structure of Chitin
Chitin has a similar structure to cellulose, as it is also composed of many β-glucose molecules joined together with 1,4 glycosidic bonds. However, chitin differs as it also contains acetylamine groups bonded to carbon 2 of the β-glucose monosaccharide. Like in cellulose, the β-glucose molecules are inverted to form the 1,4 glycosidic bonds. This means that the chitin chains are straight. The long, straight chitin chains lie parallel to each other, with hydrogen bonds forming cross-links between the chains. The cross-linked chitin chains bundle together to form stronger microfibrils. These strong chitin microfibrils are deposited around the cell, adding strength to the fungal cell wall.
Summary
Chitin is a polysaccharide that is used to strengthen fungal cell walls
Chitin is also used to strengthen and waterproof insect exoskeletons
Chitin has a similar structure to cellulose, with the addition of an acetylamine group on carbon 2 of the β-glucose molecules
The chitin chains are very long and straight and are held together by thousands of cross-linking hydrogen bonds
The chitin chains bundle into stronger microfibrils which add strength to fungal cell walls
SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* Oxbridge tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks.
Sign up today and together, let’s make A-level Biology a walk in the park!
The key points covered in this video include:
1. Structural Polysaccharides - Chitin
2. Structure of Chitin
Structural Polysaccharides - Chitin
As well as cellulose in plants, structural polysaccharides can be found in other organisms, such as fungi and insects. In fungi, a polysaccharide called chitin is used to strengthen the cell wall. In insects, chitin is also used to give strength to their exoskeleton. Chitin is also waterproof which helps insects prevent water loss from their body.
Structure of Chitin
Chitin has a similar structure to cellulose, as it is also composed of many β-glucose molecules joined together with 1,4 glycosidic bonds. However, chitin differs as it also contains acetylamine groups bonded to carbon 2 of the β-glucose monosaccharide. Like in cellulose, the β-glucose molecules are inverted to form the 1,4 glycosidic bonds. This means that the chitin chains are straight. The long, straight chitin chains lie parallel to each other, with hydrogen bonds forming cross-links between the chains. The cross-linked chitin chains bundle together to form stronger microfibrils. These strong chitin microfibrils are deposited around the cell, adding strength to the fungal cell wall.
Summary
Chitin is a polysaccharide that is used to strengthen fungal cell walls
Chitin is also used to strengthen and waterproof insect exoskeletons
Chitin has a similar structure to cellulose, with the addition of an acetylamine group on carbon 2 of the β-glucose molecules
The chitin chains are very long and straight and are held together by thousands of cross-linking hydrogen bonds
The chitin chains bundle into stronger microfibrils which add strength to fungal cell walls
5 سال پیش
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