4. Biological Molecules Flashcards
Importance of Biological Molecules
Build Structure
Metabolic Reactions
Chemical elements in Carbohydrates
Carbon, Hydrogen, Oxygen C,H,O
Chemical elements in Lipids
Carbon, Hydrogen, Oxygen C,H,O
Chemical elements in Protiens
Carbon, Hydrogen, Oxygen, Nitrogen, and Sulpher (C,H,O,N,S)
Small amounts of other elements
What Smaller molecules are starch and glycogen made from?
Gulcose
Smaller particles of protein
Amino Acids
Smaller particles of fats and lipids
Fatty acids and glycerol
what the hell is carbohydrates made of. the answer is Carbohydrates
Long chains of simple sugars
Glucose is a simple sugar ( a monosaccharide)
When 2 glucose molecules join together maltose is formed (a disaccharide)
When lots of glucose molecules join together starch, glycogen or cellulose can form (a polysaccharide)
Fats
my mother and father
Most fats (lipids) in the body are made up of triglycerides Their basic unit is 1 glycerol molecule chemically bonded to 3 fatty acid chains The fatty acids vary in size and structure Lipids are divided into fats (solids at room temperature) and oils (liquids at room temperature)
what the hell are protienes Proteins
Long chains of amino acids
There are about 21 different amino acids
They all contain the same basic structure but the ‘R’ group is different for each one
When amino acids are joined together a protein is formed
The amino acids can be arranged in any order, resulting in hundreds of thousands of different proteins
Even a small difference in the order of the amino acids results in a different protein being formed
How do you test for starch?
We can use iodine to test for the presence or absence of starch in a food sample.
Add drops of iodine solution to the food sample
A positive test will show a colour change from orange-brown to blue-black
Iink: https://www.savemyexams.co.uk/notes/igcse-biology-cie-new/4-biological-molecules/4-2-food-tests/
Test for reducing sugars?
Add Benedict’s solution into sample solution in test tube
Heat at 60 – 70 °c in water bath for 5 minutes
Take test tube out of water bath and observe the colour
Iink: https://www.savemyexams.co.uk/notes/igcse-biology-cie-new/4-biological-molecules/4-2-food-tests/
Test for Protiens
Add drops of Biuret solution to the food sample
Test for lipids
Food sample is mixed with 2cm3 of ethanol and shaken
The ethanol is added to an equal volume of cold water
Test for Vitamin C
Add 1cm3 of DCPIP solution to a test tube
Add a small amount of food sample (as a solution)
