1.2.8 - Polysaccharides Flashcards
What Are Polysaccharides?
Are repeating chains of many monosaccharides, joined by glycosidic bonds in a condensation reaction.
What Can Polysaccharides Be?
(2 Points)
~ Branched or unbranched.
~ Straight or coiled.
What Are Examples Of Polysaccharides?
(3 Points)
~ Starch.
~ Glycogen.
~ Cellulose.
What Does It Mean When A Polysaccharide Is Branched?
Increases the rate at which the polysaccharide can be broken down.
What Does It Mean When A Polysaccharide Is Straight?
Makes the molecules suitable for constructing cellular structures. E.g. Cellulose.
What Does It Mean When A Polysaccharide Is Coiled?
Makes the molecule more compact and suitable for storage.
What Are Starch & Glycogen Useful As?
Storage polysaccharides.
Why Are Starch & Glycogen Useful Storage Polysaccharides?
(2 Points)
~ Compact.
~ Insoluble.
Starch & Glycogen Are Compact, What Does This Mean?
Large quantities can be stored.
Starch & Glycogen Are Insoluble, What Does This Mean?
They will have no osmotic effect.
How Does Glucose Have An Osmotic Effect?
It increases the solute concentration of a cell, causing water to move in by osmosis.
Describe Starch
(4 Points)
~ Main energy storage material in plants.
~ Stored as granules inside plant cells.
~ Cells get energy from glucose, plants store excess glucose as starch. Once a plant needs more glucose for energy it breaks down starch to release the glucose.
~ Starch is a mixture of Amylose + Amylopectin.
Describe AMYLOSE As A Component Of Starch
(2 Points)
~ Long, unbranded helix-shaped chain with 1,4 glycosidic bonds between alpha-glucose molecules.
~ The helix shape enables it to be more compact, making it good for storage as more can be fit in a small space.
Describe AMYLOPECTIN As A Component Of Starch
(2 Points)
~ Branched, containing 1,4 and 1,6 glycosidic bonds between the alpha glucose molecules.
~ Its side branches allow the enzymes to break down the molecule to access the glycosidic bonds easily, allowing for quick release of glucose.
Describe Glycogen
(6 Points)
~ Main energy storage material in animals and fungi.
~ Animals store access glucose as glycogen.
~ Highly branched and not coiled.
~ Contains 1,4 and 1,6 glycosidic bonds.
~ More branched than amylopectin, means that stored glucose can be released quicker, essential for animals.
~ Very compact and large, so very good for storage.
