Polysaccharides Flashcards
What are polysaccharides made by?
Condensation reaction between many glucose monomers.
Where is starch found?
Found in starch grains inside plant cells e.g inside chloroplasts.
What is the function of starch?
It is an insoluble store of glucose.
What is starch made up of?
Formed from 2 polymers of alpha glucose - amylose and amylopectin.
What reaction makes amylose?
Condensation reaction with a 1,4 glycosidic bond.
Structure of amylose?
An unbranched chain of glucose molecules joined by 1, 4 glycosidic bonds. As a result amylose is coiled into a helix and thus a very compact molecule storing a lot of energy.
What reaction forms amylopectin?
Condensation reaction made from 1-4 and 1-6 glycosidic bonds.
Structure of amylopectin?
Branched.
Difference between the structure of amylose and amylopectin?
Amylopectin is a branched polymer.
Amylose is a straight polymer which spirals up.
What is glycogen made up of?
Alpha glucose.
Where is glycogen found?
In animals inside muscle and liver cells.
What is the function of glycogen?
Insoluble store of glucose.
What reaction forms glycogen?
Many condensation reactions between alpha glucose.
What type of bonds are present in glycogen?
1-6 and 1-4 glycosidic bonds.
What other structure is similar to glycogen?
Amylopectin
What is the difference in structure between glycogen and amylopectin?
Glycogen has more 1-6 glycosidic bonds compared to amylopectin.
Structure of glycogen?
Highly branched and highly compact.
How does the structure of glycogen lead to the function?
Branched structure increases surface area for rapid hydrolysis back to glucose. Insoluble - won’t affect water potential.
Insoluble - doesn’t diffuse out of cells.
How does the structure of starch lead to the function?
Insoluble - doesn’t affect water potential so water isn’t drawn into the cells by osmosis.
Large and insoluble - it doesn’t diffuse out of cells.
Compact - a lot of glucose can be stored in a small space.
What is cellulose made up of?
Beta glucose.
Where is cellulose found?
In the cell wall of plant cells.
Function of cellulose?
Provides structural strength to cell wall which prevents the cell from bursting when it becomes turgid with water.
What reaction forms cellulose?
Condensation reaction 1-4 glycosidic bonds so it only has straight chains.
Structure of cellulose?
Long straight chains lie parallel held together by many hydrogen bonds. This is a fibril.
