3.3 Carbohydrates Flashcards
What elements do carbohydrates contain?
carbon, hydrogen and oxygen
What ratio do the elements appear in?
Cx(H2O)y (general formula)
What are carbohydrates known as?
saccharides or sugars
What is a simple sugar?
- monosaccharide
- e.g. glucose, fructose and ribose
- 2 mono = 1 disaccharide
- 2+ mono = polysaccharide
What are some examples of polysaccharides?
Glycogen, cellulose, and starch
What are some examples of disaccharides?
Lactose and Sucrose
What are the main components of glucose?
- formula of C6H12O6
- monosaccharide composed of six carbons (hexose)
- two variations: alpha and beta
What’s the difference between alpha glucose and beta glucose?
OH group on carbon one are in different positions
Beta = above carbon, like carbon 3
Alpha = below carbon, like carbon 2 and 4
What is a condensation reaction in terms of carbohydrates?
2 alpha glucose molecules side by side, Hydroxyl groups interact - bonds broken and made (-H2O)
What is the bond called between two carbohydrate molecules?
Glycosidic bond eg. 2 glucose= 1 maltose
What are some other sugars?
- Fructose and Galactose (hexose monosaccharides)
- Galactose and glucose = lactose
- Ribose (RNA) and Deoxyribose (DNA) (pentose monosaccharides)
What are the main components of starch?
- glucose made by photosynthesis in plant cells
- chemical energy store
- eg. amylose (1,4 Glycosidic bonds, stabilized by hydrogen bonding within the molecule, less soluble)#
- eg. amylopectin (1,4 Glycosidic bonds followed by 1,6 every 25 glucose subunits)
What are the main components of Glycogen?
- energy store in animals and fungi
- more branches than amylopectin, more compact
- free ends where glucose added can be added or removed
- insoluble
What are hydrolysis reactions?
+H2O, reverse of condensation reactions
