1.2- CARBOHYDRATES- MONOSACCHARIDES Flashcards
What unusual feature do carbon atoms have?
very readily form bonds with other carbon atoms
What does carbon atoms very readily forming bonds with other carbon atoms mean?
sequence of carbon atoms of various lengths to be built up
What does a sequence of carbon atoms of various lengths building up form?
a ‘backbone’ along which other atoms can be attached
What does a ‘backbone’ along which other atoms can be attached permit?
a large number of diff types and sizes of molecule, all based on carbon
What did the versatile carbon atom cause?
variety of life that exists on Earth
What are carbon-containing molecules known as?
organic molecules
What are most polymers made up of?
carbon
hydrogen
oxygen
nitrogen
What is the basic monomer unit in carbohydrates?
sugar- saccharide
Single monomer saccharide
monosaccharide
Pair of monosaccharides combined to form
disaccharide
monosaccharides combined in much larger numbers
polysaccharides
What are monosaccharides
sweet-tasting, soluble substance
general formula of monosaccharide
(CH₂O)ₙ
ₙ- any number from 3-7
E.g. of monosaccharides
glucose, galactose and frutcose
What is glucose and formula?
hexose (6-carbon) sugar
formula- C₆H₁₂O₆
What are all monosaccharides and some disaccharides?
reducing sugars
What is reduction?
chemical reaction involving gain of electrons or hydrogen
So what is a reducing sugar?
sugar that can donate electrons to another chemical, in this case Benedict’s reagent
What is the test for reducing sugar
Benedict’s test
What is Benedict’s solution
alkaline solution of copper (II) sulfate
What happens when a reducing sugar is heated with Benedict’s reagent?
forms an insoluble red precipitate of copper (I) oxide
How is the benedict test carried out?
1) add 2cm³ of food sample to test tube. if not in liquid form, grind up in water
2) add an equal vol of benedict’s reagent
3) heat mixture in a gently boiling water bath for 5 mins
