L10 - Polysaccharides Flashcards
What is a polysaccharide?
Many monosaccharide monomers joined by glycosidic bonds
Describe the structure of glucose
C6H12O6
Hexo sugar
What is the function of glucose?
respiratory substrate
good source of energy
How is glucose adapted for its function?
small + soluble
which makes it a good metabolite
describe the structure of starch (in general)
alpha glucose monomers in polysaccharides
What is the function of starch?
storage polymer in plants
broken down to release glucose for energy
How is starch adapted for its function?
very compact, large, insoluble
which makes it ideal for storage
hydrolysis easily (to release monomer)
what are the two types of starch?
amylose
amylopectin
describe the structure of amylose?
1,4 glycosidic bond
describe the structure of amylopectin?
1,4 glycosidic bond + occasional 1,6 glycosidic bonds which causes branching
describe the structure of glycogen
Alpha glucose monomers in polysaccharides
1,4 glycosidic bonds
1,6 glycosidic bonds (more than amylopectin, so more branched)
What is the function of glycogen?
Storage polymer in animals
Broken down to release glucose for energy
how is glycogen adapted for its function?
large, insoluble, compact
describe the structure of cellulose
Beta glucose monomers in polysaccharides
Straight chain cause of inverted beta glucoses
Cross links across parallel chains (hydrogen bonds)
What is the function of cellulose?
Structural polymer in plant cell walls
How is cellulose adapted for its function?
strong
cross links
How do you test for starch?
Place 2cm3 of starch solution in a boiling tube
Add a few drops of iodine
Observe the colour (light brown - black)
Place In a water bath of boiling water + observe any changes
Place in a beaker of cold water + observe any changes
