carbohydrates Flashcards
1
Q
what is a monosaccharide?
A
a single sugar unit
2
Q
give 2 examples of monosaccharides
A
- ribose
- glucose
3
Q
give 3 examples of disaccharides
A
- maltose
- lactose
- sucrose
4
Q
give 3 examples of polysaccharides
A
- starch
- cellulose
- glycogen
5
Q
how are carbohydrates bonded?
A
glycosidic bond
6
Q
what makes glucose a hexose monosaccharide?
A
contains 6 carbon atoms
7
Q
state the difference between alpha and beta glucose
A
in alpha glucose, the right hand carbon atom has hydrogen on top and hydroxide on the bottom
- the other way round in beta
8
Q
why is glucose soluble?
A
due to hydrogen bonding
9
Q
state 4 characteristics of glucose
A
- small
- soluble
- easily transported
- easily oxidised
10
Q
describe how a di/poly saccharide forms
A
- hydroxyl groups interact
- glycosidic bond forms between carbon 1 and carbon 4
- water is released
- condensation reaction
11
Q
describe amylose
A
- linear
1-4 glycosidic bonds - soluble
- helix chain (resistant to digestion, slow energy release)
- alpha glucose
12
Q
describe amylopectin
A
- branched
- 1-4 and 1-6 glycosidic bonds
- insoluble
- faster glucose release
13
Q
describe the structure and function of starch
A
- made of amylose and amylopectin
- joined by glycosidic bonds
- storage
14
Q
describe the structure and function of glycogen
A
- alpha glucose
- insoluble (doesn’t affect cell’s water potential)
- branched
- free ends so molecules can easily be added/removed
- storage
- many in liver/muscle for respiration
- glucose storage in animals
15
Q
describe the structure and function of cellulose
A
- insoluble
- beta glucose
- alternate monomers flipped
- linear
- hydrogen bonds form microfibrils which form strong fibres for cell walls
- 1-4 glycosidic bonds
- can stretch
- matrix provides strength
- fibres are permeable so water and solutes reach cell surface membrane
