Rev Flashcards
What is the polysaccharide energy store in plants?
Starch
Where is starch most commonly found?
In photosynthesising cells, leaves and seeds
How is starch stored?
It is compacted into dense insoluble grains
What is starch stored in?
Amyloplast
What two polysaccharides does starch consist of?
Amylase + amylopectin
Describe the structure of amylase:
A long chain of alpha glucose molecules
Coiled into a helix shape (storage purposes)
Two accessible ends where enzymes can bind
Describe the structure of amylopectin:
A long chain of alpha glucose molecules join bye 1-4 glyosidic bonds
Occasionally has 1-6 glycosidic bond
What does the addition of 1-6 glycosidic bonds mean amylopectin has?
The additional 1-6 glycosidic means amylopectin has side branches with more accessible ends
This allows amylopectin to be released quicker than amylose
What is the polysaccharide store animals?
Glycogen
What type of cells is glycogen found in?
Cells with a high metabolic rate e.g liver and muscle cells
Describe the structure of glycogen:
A long chain of alpha glucose molecules join bye 1-4 glyosidic bonds
Occasionally has 1-6 glycosidic bond
Why does glycogen have a high number of accessible ends? And why is this important?
This allows it to be rapidly hydrolysed to an alpha glucose. This important because animals require a faster metabolic rate than plants.
What type of polysaccharide is cellulose
A structural polysaccharide
Describe the structure of cellulose:
A long chain of beta glucose molecules joined by 1-4 glyosidic bonds
What do beta glucose molecules in cellulose have to do to form 1-4 glycosidic bonds
Invert 180 degrees
