1.2 - Carbohydrates Flashcards
What is an isomer?
A compound with the same formula but a different arrangement of atoms
How are monosaccharides classified?
Classified by the number of carbon atoms
What is alpha glucose found in?
Starch and glycogen
What is beta glucose found in?
Plant cell walls, cellulose
What bonds do carbohydrates form?
Glycosidic bonds by a condensation reaction
Example of a disaccharide?
Maltose, Lactose, Sucrose
Example of a polysaccharide?
Starch, Glycogen, Cellulose
What is the test for a non-reducing sugar?
No colour change so…
1) Heat sample with dilute HCl.
2) Neutralise by adding sodium hydrogen carbonate.
3) Heat with Benedict’s, positive test with give a coloured precipitate, negative will stay blue”
What is the test for reducing sugars?
1) Add Benedict’s solution. To test for the presence of a sugar.
2) Heat the mixture.
3) Observe the colour change: blue is the weakest concentration, and brick red is the highest concentration.
blue -> green -> yellow -> orange -> brick-red”
What is starch broken down into?
Maltose and glucose by hydrolysis.
Where is starch found?
Found in chloroplast and stomata.
What is starch/glycogen formed from?
Formed from alpha glucose
Why is starch used in energy storage?
It is dense and soluble
What does starch form?
Bonds to form amylopectin
Where is glycogen found?
Muscle cells in animals
What is glycogen used in?
Energy storage as it is insoluble and dense
What is cellulose formed from?
Beta glucose, for,in only 1-4 glycosidic bonds
What is the function of cellulose?
Structural
Where do the glycosidic bonds form in cellulose?
Between inverted monomers
What is a myofibrils?
Many parallel chains of cellulose
Where do hydrogen bonds form between myofibrils?
Between parallel chains which prevents water entering the molecule
What is amylose?
Long, unbranched chain of alpha glucose. Its structure makes in compact and good for storage
What is amylopectin?
Long, unbranched chain of alpha glucose, side branches allow the enzymes to get to glycosidic bonds easily, meaning glucose can be released quickly.
Is starch soluble?
Starch is insoluble in water and doesn’t affect water potential, meaning glucose can be released quickly.
