Polysaccharides Flashcards
(23 cards)
What are polysaccharides?
Long chains of sugars
Name three examples of polysaccharides.
- Starch
- Glycogen
- Cellulose
What type of glucose is starch made of?
α-glucose
What type of glucose is cellulose made of?
β-glucose
Are polysaccharides soluble or insoluble?
Insoluble
What is the primary function of starch and glycogen?
Energy-storage molecules
Where is starch primarily found?
In plants
Where is glycogen primarily found?
In animals
What are the two forms of starch?
- Amylose
- Amylopectin
How does glycogen’s structure differ from amylopectin?
Glycogen is more heavily branched and has shorter chains
Why are polysaccharides insoluble?
To prevent decreasing the water potential of the cell
What allows amylose to be compact?
It coils
What is the biochemical test for starch?
Using iodine solution
What color change indicates the presence of starch when tested with iodine?
blue-black
What structural feature of cellulose results in straight and unbranched chains?
Alternating glycosidic bonds
What type of bonds form between parallel cellulose chains?
Weak hydrogen bonds
What is the main function of cellulose in plants?
To provide structure and support to cell walls
What is a similarity between the structures of cellulose and glycogen?
Both contain glycosidic bonds
What is a difference between cellulose and glycogen regarding glucose type?
Glycogen is made of α-glucose, cellulose is made of β-glucose
True or False: Glycogen is unbranched.
False
Fill in the blank: The exoskeletons of many animals are largely composed of the polysaccharide _______.
chitin
How do cellulose chains contribute to their strength?
They form microfibrils with many hydrogen bonds
How do you perform the starch test?
- food sample into a test tube
- add few drops of iodine
3.if starch is present it turns blue-black, if not it turns orange.
