3.3 Carbohydrates Flashcards
What elements are carbohydrates made of?
C, H, O
What is a polymer?
A molecule made up of many similar smaller molecules (monomers) bonded together
What is the name of the monomers that make up carbohydrates?
Monosaccharides
What is a monosaccharide?
A single sugar molecule
Give 3 examples of monosaccharides?
Glucose, fructose, ribose
What is formed when two monosaccharides are linked?
Disaccharide
Give 3 examples of disaccharides
Lactose, sucrose, maltose
What is formed when 3 or more monosaccharides are linked together?
Polysaccharide
Give 3 examples of polysaccharides.
Glycogen, cellulose and starch
What is the formula for glucose?
C6H12O6
What type of monosaccharide is glucose? Why is this the case?
Hexose monosaccharide - glucose has 6 carbons
What are the properties of glucose?
Polar, soluble
How does the structure of glucose relate to its function?
Due to the solubility of glucose, it dissolves in the cell’s cytoplasm so can easily be transported
What is a condensation reaction?
A reaction between 2 molecules resulting in the formation of a larger molecule and the release of a water molecule.
What is a hydrolysis reaction?
Breakdown of a molecule into 2 smaller molecules requiring the addition of a water molecule.
What is the name of the bond between glucose molecules?
Glycosidic bond
What happens when two alpha glucose molecules are next to each other?
- The 2 OH/hydroxyl groups react
- 2H atoms + 1O atoms are removed from the 2 glucose monomers and join to form a water molecule
- 1,4 glycosidic bond forms between the 2 monomers, forming disaccharide maltose
What does “1,4 glycosidic bond” mean?
There is a glycosidic bond between Carbon 1 of one glucose monomer and Carbon 4 of another glucose monomer
What molecule do you get when glucose and fructose are combined?
Sucrose
What molecule do you get when glucose and galactose are combined?
Lactose
What is a pentose monosaccharide?
A monosaccharide with 5 carbons
What is formed when many alpha glucose molecules are joined by glycosidic bonds?
Starch
How is starch formed?
When many alpha glucose molecules are joined by glycosidic bonds
What are the 2 molecules which starch is composed of?
Amylose + amylopectin
How is amylose formed?
When alpha glucose molecules are joined only by 1-4 glycosidic bonds
How is the structure of amylose related to its properties?
The angle of the bonds forming amylose means the molecule twists to form a helix, stabilised by H bonds within.
This makes amylose more compact (good for storage) and less soluble than glucose.
How is amylopectin formed?
Formed by 1-4 glycosidic bonds between alpha gluc mlcs but also some 1-6 glycosidic bonds between alpha gluc mlcs formed by condensation reactions
How does the structure of amylopectin relate to its
..
What are the 2 key structural differences between amylose and amylopectin?
Amylose is unbranched, amylopectin is branched
