1.1 Carbohydrates Flashcards
What are the features of a monosaccharide?
fructose, galactose, ribose
general formula - (CH2O)n
can be triose, pentose or hexose sugars
What are the features of a disaccharide?
2 monosaccharides joined together in a condensation reaction
sucrose, lactose, maltose
What are the features of a polysaccharide?
starch, glycogen, cellulose
form compact molecules
physically and chemically inactive
insoluble in water - don’t affect water potential
Describe the structure of alpha glucose
carbon 1 - hydrogen above hydroxyl group
c2 - H, OH
c3 - OH, H
c4 - H, OH
c5 - CH2OH, H
Describe the structure of beta glucose
carbon 1 - hydroxyl group above hydrogen
c2 - H, OH
c3 - OH, H
c4 - H, OH
c5/6 - CH2OH, H
and an oxygen between c5 and c1
Describe the structure of pentose ribose
oxygen
c1 - H, OH
c2 - H, OH
c3 - H, OH
c4/5 - CH2OH, H
Describe how a condensation reaction works
a molecule of water is removed from the 2 molecules reacting as a bond is formed between them
What are the 3 types of bonds formed in a condensation reaction?
glycosidic
ester
peptide
What occurs in a hydrolysis reaction?
the bond formed in the condensation reaction is broken by the addition of 1 molecule of water
How does the structure of glucose relate to its function?
glucose
- is an energy sure - it can be used in respiration to make ATP
- it is soluble so it can be transported through an organisms body
Describe the structure of starch
made up of amylose and amylopectin:
- amylose is unbranched polymer that forms compact spirals. it is made up of 1,4 alpha glucose molecules
-amylopectin is a branched polymer - it can be broken off rapidly for energy. its made from 1,4 and a few 1,6 alpha glucose molecules
How does the structure of starch relate to its function?
combination of branched and straight-chain molecules
amylopectin releases glucose for cellular respiration rapidly when needed - its branched so breaks down quicker
amylose releases glucose slowly, over a longer period of time
How does the structure of glycogen relate to its function?
- its the only carbohydrate energy store found in animals
- it is formed from alpha glucose with many 1,6 and a few 1,4 glycosidic bonds
- very compact
- branches mean it can break down quickly so it is ideal for active tissues with constant high rate of cellular respiration
- this is why it is found in muscles and the liver
How does the structure of cellulose relate to its function?
cellulose molecules are made of beta glucose molecules - 1,4 glycosidic bonds
every other molecule is inverted so bonding can occur
this means cellulose is an extremely strong material
