Biological molecules: Carbohydrates Flashcards
What are biological molecules?
Substances where a C-H bond is present
What is a monomer?
The individual molecules that make up polymers
Why is carbon dioxide an inorganic molecule?
It doesn’t have the C-H bond
What chemical elements are polymers usually based on?
Carbon, hydrogen, oxygen and nitrogen
What is a monosaccharide?
The basic monomer unit of carbohydrates
What is a disaccharide?
2 monosaccharide units joined together to form a glycosidic bond in a condensation reaction
What is a polysaccharide?
A long chain of monosaccharides
Give the four monomers you need to know and their corresponding polymer
Amino acids - proteins
Nucleotides - nucleic acids (DNA, RNA)
glycerol and fatty acids - triglyceride fats
Monosaccharides - polysaccharides (these are under carbohydrates which refers to both monomer and polymer)
What is the general formula of a monosaccharide?
(CH ₂O)n where n can be any number from 3 to 7
Give three examples of monosaccharides
Glucose, fructose and galactose
What kind of sugar is glucose?
A hexose sugar because it had 6 carbons
What are the two isomers of glucose and draw them.
Alpha glucose and beta glucose ( drawing in camera roll)
What is a reducing sugar?
A sugar that can donate electrons to (or reduce) another chemical (in this case that chemical is benedicts solution)
What is reduction?
A chemical reaction involving the gain of electrons or hydrogen
What is the test for reducing sugars and how do you carry it out?
Benedict’s test:
- Add 2cm of the food sample to be tested in a test tube and it should be in liquid for, by grinding it up in water
- Add an equal volume of benedict’s reagent
- Heat the mixture in a gently boiling water bath for 5 minutes. If reducing sugar is present, solution turns orange-brown