Biological Molecules Flashcards
What are the three categories of molecules in living organisms?
Carbohydrates, proteins, and lipids.
What do organic molecules contain?
Carbon.
What are carbohydrates made of?
Long chains of simple sugars.
What is glucose?
A simple sugar (a monosaccharide).
What is formed when 2 glucose molecules join together?
Maltose (a disaccharide).
What can form when many glucose molecules join together?
Starch, glycogen, or cellulose (a polysaccharide).
What are most fats in the body made up of?
Triglycerides.
What is the basic unit of triglycerides?
1 glycerol molecule chemically bonded to 3 fatty acid chains.
How are lipids divided?
Into fats (solids at room temperature) and oils (liquids at room temperature).
What are proteins made of?
Long chains of amino acids.
How many different amino acids are there?
About 20.
What is the significance of the ‘R’ group in amino acids?
It is different for each amino acid.
What happens when amino acids are joined together?
A protein is formed.
What results from the arrangement of amino acids?
Hundreds of thousands of different proteins.
What is the food test for glucose?
Add Benedict’s solution to the sample, heat, and observe the color change.
What indicates a positive test for glucose?
A color change from blue to orange or brick red.
How do you test for starch?
Add drops of iodine solution to the food sample.
What indicates a positive test for starch?
A color change from orange-brown to blue-black.
What is the food test for protein?
Add drops of Biuret solution to the food sample.
What indicates a positive test for protein?
A color change from blue to violet/purple.
How do you test for lipids?
Mix the food sample with ethanol, then add to cold water.
What indicates a positive test for lipids?
A cloudy emulsion forming.
Elements
Test for Glucose
