1.3 — carbohydrates: monosaccharides and disaccharides Flashcards
what is another name for monosaccharides?
simple sugars
monosaccharides are s______, s____-t______ and are found in many foods such as f_____, v_________ and g____. what are the missing terms?
soluble/sweet-tasting/fruits/vegetables/grains
what is the general formula of monosaccharides and what range of numbers can ‘n’ be?
the general formula — (CH2O)n
the range of n — 3-7
how are monosaccharides classified?
according to the number of carbon atoms in each molecule
what is a hexose sugar?
a sugar with 6 carbon atoms
what is a ribose sugar?
a sugar with 5 carbon atoms
what are three examples of a hexose sugar?
glucose, fructose and galactose
what are two examples of pentose sugars?
ribose and deoxyribose
what is the formula of glucose?
C6H12O6
what are the two isomers of glucose?
alpha and beta
what position is the hydroxyl group in alpha glucose?
at the bottom of the molecule
what position is the hydroxyl group in beta glucose?
at the top of the molecule
glucose is used as the _______ energy source in animals and plants. what is the missing term?
primary
what two features of glucose help it function as an energy source?
1 . it is soluble — the hydroxyl groups can form hydrogen bonds with water, so it can be transported around organisms
- its bonds store lots of energy — this energy is released when the bonds are broken
when are disaccharides formed and by what bond?
when two monosaccharides join together though condensation reaction by a glycosidic bond
what are three examples of disaccharides?
maltose, sucrose and lactose
where is maltose found?
in grains and cereals
what is sucrose used for?
a transport sugar in plants
where is lactose?
in milk (as the main carbohydrate)
what two monosaccharides form maltose?
2x alpha glucose
what two monosaccharides form sucrose?
glucose x fructose
what two monosaccharides form lactose?
glucose x galactose
how are disaccharides formed?
condensation reactions between two monosaccharides
how are disaccharides broken down?
hydrolysis reactions
what is the covalent bond between disaccharides?
glycosidic bond
how are 1,4 glycosidic bonds formed?
the OH group on carbon one reacting with the OH group on carbon four of another monosaccharide
what happens when a water molecule is added to a disaccharide?
the 1,4 glycosidic bonds is broken to release the 2 monosaccharides
how is glucose soluble and what is the outcome?
the hydroxyl groups can form hydrogen bonds with water, so it can be transported around organisms
