Carbohydrates Flashcards
What is carbon and its properties?
- 6 electrons, can form covalent bonds
-4 on outer shell so forms 4 bonds
What are carbohydrates and their main function in organisms?
- made up of carbon, oxygen and hydrogen
- used as an energy source and structural materials
What are the properties of monosaccharides and examples?
- simple sugars
- all contain a C=O (carbonyl group) and at least two OH (hydroxyl groups)
- most common are glucose (alpha or beta), fructose + galactose
- reducing sugars —> can ‘donate’ electrons to other chemicals
What are properties of glucose and two types?
- C6H12O6
- contains 6 carbons = hexose sugar
- major energy source for cells; highly soluble
- exist as structural isomers, alpha or beta
~ only difference is position of -OH attached to carbon 1 (alpha below, beta above)
Describe/Draw the structure of glucose (either type)
C1, 2, 3, 4 attached to OH and H; C5 attached to C6 which is CH2OH, plus Oxygen
What are properties of fructose and galactose?
fructose - very soluble + is main sugar in fruits/nectar
- pentose sugar
galactose - not as soluble but important role in production of glycoproteins/lipids
- also a hexose sugar
What are disaccharides + main types
- formed with two monosaccharides
-maltose (gluc+gluc), sucrose (gluc+fruc), lactose (gluc+galac)
How are disaccharides formed ?
In a condensation reaction between two monosaccharides - results in a 1,4 glycosidic bond between C1 and C4 + releases water
What polysaccharides is starch made up of?
- amylose + amylopectin
Describe properties of amylose
- made up of many alpha glucoses w/ 1,4 glycosidic bonds
- unbranched so can form a helix held together by many hydrogen bonds
Describe properties of amylopectin
- also formed from 1,4 glycosidic bonds of alpha glucoses
- BUT has branches ~ every 25-30, which are 1,6 glycosidic bonds
- more branches = more ends for enzymes to hydrolysis (converting it back to simple sugars), so is more immediate source of energy
