Carbohydrates Flashcards
What is a monosaccharide?
monomers from which larger carbohydrates are made
Give three examples of monosaccharides.
glucose, fructose and galactose
What is a disaccharide?
Two monosaccharides joined by a glycosidic bond through a condensation reaction
Give three examples of disaccharides
maltose, lactose and sucrose
What is maltose formed from?
two glucose monosaccharides
What is lactose formed from?
glucose and galactose
What is sucrose formed from?
glucose and fructose
What is a polysaccharide?
a large molecule formed from the condensation reaction of many glucose units joined by glycosidic bonds
What are the two isomers of glucose?
a glucose and b glucose
How does a and b glucose differ?
a glucose has two hydroxide groups facing downward whereas b glucose has one hydroxide facing upward and one facing downward
What are the three polysaccharides?
Starch, glycogen and cellulose
What is the structure of starch?
- starch is formed of amylose and amylopectin
What is the structure of amylose?
- amylose is an unbranched chain of glucose molecules joined by 1.4 glycosidic bonds.
- This means it is unbranched and coiled, compact
What is the structure of amylopectin?
- branched and made up of 1,4 and 1,6 glycosidic bonds
- contains many side chains which can be acted upon by enzymes
What are the properties of starch?
- it is insoluble so it does not affect the osmotic potential of cells
- it is large and insoluble so it doesn’t diffuse out of cells
- compact, can be stored
- it has branched ends which enzymes can act on so it can be easily broken down