Carbohydrates - Monosaccharides - 1.2 Flashcards
What are carbohydrates?
Carbon molecules (carbo) combined with water (hydrate).
What are carbon-containing molecules known as?
Organic molecules
What is the variety of life that lives on earth a consequence of?
Organisms being based on the versatile carbon atom.
What is a monomer?
One of many small molecules that combine to form larger ones known as polymers.
What are some examples of monomers?
- Monosaccharides
- Amino Acids
- Nucleotides
What are polymers?
Molecules made from many monomers joined together.
What are some examples of polymers?
- Carbohydrates
- Proteins
What are the four elements that make up most polymers?
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
What is the basic carbohydrate monomer?
A sugar known as a saccharide.
What is a single carbohydrate monomer called?
Monosaccharide
What is a pair of carbohydrate monomers called?
Disaccharide
What are many carbohydrate monomers called?
Polysaccharides
What are monosaccharides?
Sweet-tasting, soluble substances that have the general formula (CH20)n, where n can be any number from three to seven.
What are example of monosaccharides?
- Glucose
- Galactose
- Fructose
What are the two isomers of glucose?
- Alpha-glucose
- Beta-glucose
What are reducing sugars?
All monosaccharides and some disaccharides (e.g. maltose) are reducing sugars.
What is reduction?
A chemical reaction involving the gain of electrons or hydrogen.
What is a reducing sugar?
A sugar that can donate electrons to (or reduce) another chemical.
What is the test for reducing sugars?
The Benedict’s test
What is Benedict’s reagent?
An alkaline solution of copper (II) sulphate.
What happens when a reducing sugar is heated with Benedict’s reagent?
An insoluble red precipitate of copper (II) oxide
What is the Benedict’s test for reducing sugar?
- Add 2cm3 of the food sample to be tested to a test tube. If the sample is not already in liquid form, first grind it up in water.
- Add an equal volume of Benedict’s reagent.
- Heat the mixture in a gently boiling water bath for five minutes.
- If reducing sugar is present, solution turns orange-brown.
