Carbohydrates Flashcards
What’s a polymer?
Large, complex molecules composed of large chains of monomer s joined together.
What’s a monomer?
Small, basic molecular unit.
3 examples of monomers
Amino acids, monosaccharides and nucleotides
What type of bond is formed between a two monosaccharides during a condensation reaction?
Glycosidic
Glucose+glucose=?
Maltose
Glucose+fructose=?
Sucrose
Glucose+galactose=?
Lactose
What’s sugar a general term for?
Monosaccharides and disaccharides.
What’s the test for sugars called?
Benedict’s test
How do you test for a reducing sugar?
Add Benedict’s reagent to sample and heat.
Positive=coloured precipitate.
Blue>brick red
How do you test for a non-reducing sugar?
Neg for reducing sugar.
Get sample and add dilute hcl and heat.
Neutralise with sodium hydrogencarbonate.
Carry out Benedict’s test- add Benedict’s reagent and heat.
Pos= colour change, blue>brick red.
What’s starch the main energy storage material in?
Plants
How do plants store excess glucose?
As starch
What does a plant do when it needs more glucose for energy?
Breaks down starch
Which two polysaccharides is starch a mixture of?
Amylose and amylopectin
What structure does amylose have?
Long, unbranched chain of alpha glucose.
Coiled shape.
Why does amylose have a coiled structre?
The angles of the glycosidic bonds
Why’s amylose good for storage?
Compact- due to coiled structure.
Fit more in a small space.
What’s the structure of amylopectin?
Long, branched chain of alpha glucose.
Side branches.
Why can the glucose in amylopectin be released quickly?
Side branches allow enzymes to break down molecule to get at glycosidic bonds easily.
How does starch not cause water to enter cells by osmosis?
Insoluable in water
Doesn’t affect water potential
Good for storage
How do you do the iodine test for starch?
Add iodine dissolved in potassium iodide solution to sample.
Pos= browny-orange to blue-black colour change.
What’s glycogen the main energy storage material in?
Animals.
How do animals store excess glucose?
As glycogen (another polysaccharide of alpha glucose)
What’s the structure of glycogen?
Similar to amylopectin but more side branches.
Why is amylopectins structure important for energy release in animals?
Lots of branches means stored glucose can be released quickly.
Why is amylopectin good for storage?
Compact.
What is cellulose a major component in?
Plant cell walls.
What’s cellulose’s structure?
Long, unbranched chains of beta-glucose.
Straight cellulose chains.
Bonds that link cellulose chains?
Hydrogen
What are the storm fibres formed when cellulose chains link?
Microfibrils.
