3.1.2.4 Polysaccharides structure and function and the starch test Flashcards
How is the structure of cellulose suited to its function?
- β-Glucose molecules can form long straight chains
- Parallel chains of cellulose form hydrogen bond ‘cross links’ which add strength
- Cellulose is arranged into microfibrils and then fibres, which add yet more strength
Which type of bond forms between adjacent α-glucose molecules in glycogen?
α 1-4 glycosidic bonds
Unbranched starch (amylose) coils into a…
compact helix structure
What test is described below:
Place 2 cm3 of the sample being tested into a test tube
Add 2 drops of iodine solution
A blue black colouration indicates a positive result
The test for starch
Identify the polysaccharide
Starch (amylose)
Identify the polysaccharide
Starch (amylopectin)
What form does starch take within plant cells?
Starch grains
Which type of bond forms between branching α-glucose molecules in glycogen?
α 1-6 glycosidic bonds
Which type of bond forms between unbranched starch (amylose) molecules?
α 1-4 glycosidic bonds
Identify the polysaccharide
Cellulose
How is glycogen different to starch?
Glycogen has many more branches
Identify the polysaccharide
Glycogen (more branches than starch)
Which type of organism contains starch?
Plants
What form does glycogen take in cells?
granules within muscle and liver cells
What type of reaction occurs when monosaccharides join?
Condensation reaction