1A - Carbohydrates 2: Polysaccharides Flashcards
1
Q
polysaccharides
A
- made of many monosaccharide units joined by condensation reactions that create glycosidic bonds
- no sweet taste
2
Q
oligosaccharides
A
molecules with 3 - 10 sugar units
3
Q
true polysaccharides
A
molecules containing 11 or more monosaccharides
4
Q
hydrolysis
A
- a reaction in which bonds are broken by the addition of a molecule of water
- the glycosidic bond between glucose units is split by hydrolysis
5
Q
monosaccharides and disaccharides as an energy source
A
- good source of instant ATP
- eg fructose is easily absorbed in the body and converted into glucose
- cannot be used to store energy, bcs they are chemically active and are very soluble in water which affects the water balance of the cells
6
Q
why are polysaccharides ideal as energy storage molecules within a cell
A
- form compact molecules (takes up little space)
- physically and chemically inactive (do not interfere with other functions of the cell)
- not very soluble in water (have almost no effect on water potential within a cell and cause no osmotic water movements
7
Q
starch (functions, properties, its monos and its compounds)
A
- energy store in plants
- insoluble and compact
- consists of long-chained a-glucose
- mixture of two compounds: amylose and amylopectina
8
Q
amylose
A
- unbranched polymer (200 - 500 glucose units)
- as the chain lengthens the molecules spirals => more compact for storage
- has only 1, 4-glycosidic bonds
9
Q
amylopectin
A
- branched polymer of glucose units
- the branching chains have many terminal glucose units that can be broken off when energy is needed
- has both 1,4-glycosidic and 1,6-glycosidic bonds
10
Q
glycogen
A
- only carbohydrate energy store in animals (and fungi)
- chemically very similar to amylopectin, but has more 1,6-glycosidic bonds => more side branches => glycogen broken down very rapidly
- ideal for animals which require rapid release of energy at certain times
